Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

22 files changed, 4914 insertions, 0 deletions

diff --git a/third_party/rust/png/.cargo-checksum.json b/third_party/rust/png/.cargo-checksum.json
new file mode 100644
index 0000000000..7ab63698df
--- /dev/null
+++ b/third_party/rust/png/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{"CHANGES.md":"8e911a50bdb41ddae0e40f629a1e1e6be7a50e7351ed5c2879c7cf69f49e2ecf","Cargo.lock":"816e27b455f10525f6c17db52aa3ab5c149bd73d8b70f68f884e689b8be5469f","Cargo.toml":"eb9223a451850fd57aa564fcf5f8a42729fe25f55ca3ce78f4578b7361ae1555","Dockerfile":"c11639c29932f0ce19bd51d48ddbbe95cfe2baf978e1432d83a02e8c00273b62","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"eaf40297c75da471f7cda1f3458e8d91b4b2ec866e609527a13acfa93b638652","README.md":"86b59909aec85ba466fb3821bf0a4beee741486f1199401d12b6f9039951ccd7","benches/README.md":"0c60c3d497abdf6c032863aa47da41bc6bb4f5ff696d45dec0e6eb33459b14b0","benches/decoder.rs":"81a13f5c731f674cc21a6aa472bcf4cc6c3581a41b1e002fa3996fc9a6e0dfe5","examples/pngcheck.rs":"afc0b028c08302d6c041e90201d217482237d09a4495adc360a97c385b311cdb","examples/show.rs":"ccd00c9d1cb7b6b1c2e181994dec6ebdee32c7d5ac9c5bc5592de4496256d696","fuzzit.sh":"b9e93f9bd504b0277dbdecc5148099b7c02080a14d694a71f31cba7a8fa06a11","src/chunk.rs":"f8aa01e68683b5cd41ac2580ac11f2d6a6190c52007e3f115dc5b7c3b0354e63","src/common.rs":"a0bc64f16cfdf511925a2869d9fda70ed07272a8278c1d2db142821babd4c931","src/decoder/mod.rs":"5cdb1cdbc7b52846053437b9730f150284929db1dc174280f3485cb25f9528c9","src/decoder/stream.rs":"656a694867c66cac107a1be981baf9429a232a5f077dcd120be47f5c1afcde91","src/encoder.rs":"a50bdece254e79ed4f633488ea49a5bf2d657bbcf0af552249305ca855b086cf","src/filter.rs":"d21d6f3d87044a6dd71d17e3fcdf23bf41fe23486123dc683c5b63b4e9b33c68","src/lib.rs":"533ca87e8771468637d4cdc0a2def4737b1e74e98ff69a8c11296d905e8ad34e","src/traits.rs":"0a5ae6012e567acdf46aff9d09e89c713d3fa7c399e32a3580b07b86b5f87ef5","src/utils.rs":"ff368caa4ecf41401b51f9d1f693f014079ae2fa369b668505bbc1b1b065d4f6"},"package":"ef859a23054bbfee7811284275ae522f0434a3c8e7f4b74bd4a35ae7e1c4a283"}
\ No newline at end of file
diff --git a/third_party/rust/png/CHANGES.md b/third_party/rust/png/CHANGES.md
new file mode 100644
index 0000000000..f7b038013c
--- /dev/null
+++ b/third_party/rust/png/CHANGES.md
@@ -0,0 +1,24 @@
+## 0.15.3
+
+* Fix panic while trying to encode empty images. Such images are no longer
+  accepted and error when calling `write_header` before any data has been
+  written. The specification does not permit empty images.
+
+## 0.15.2
+
+* Fix `EXPAND` transformation to leave bit depths above 8 unchanged
+
+## 0.15.1
+
+* Fix encoding writing invalid chunks. Images written can be corrected: see
+  https://github.com/image-rs/image/issues/1074 for a recovery.
+* Fix a panic in bit unpacking with checked arithmetic (e.g. in debug builds)
+* Added better fuzzer integration
+* Update `term`, `rand` dev-dependency
+* Note: The `show` example program requires a newer compiler than 1.34.2 on
+  some targets due to depending on `glium`. This is not considered a breaking
+  bug.
+
+## 0.15
+
+Begin of changelog
diff --git a/third_party/rust/png/Cargo.lock b/third_party/rust/png/Cargo.lock
new file mode 100644
index 0000000000..8d48d1f87d
--- /dev/null
+++ b/third_party/rust/png/Cargo.lock
@@ -0,0 +1,1142 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "adler32"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "andrew"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "line_drawing 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rusttype 0.7.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "walkdir 2.2.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "xdg 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "xml-rs 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "android_glue"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "approx"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "num-traits 0.2.9 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "arrayref"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "arrayvec"
+version = "0.4.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "nodrop 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "arrayvec"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "autocfg"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "backtrace"
+version = "0.3.40"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "backtrace-sys 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-demangle 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "backtrace-sys"
+version = "0.1.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cc 1.0.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "base64"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "bitflags"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "blake2b_simd"
+version = "0.5.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "arrayref 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "arrayvec 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "constant_time_eq 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "block"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "byteorder"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "c2-chacha"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "ppv-lite86 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "cc"
+version = "1.0.46"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "cfg-if"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "cgl"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "gleam 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "cloudabi"
+version = "0.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "cocoa"
+version = "0.18.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "block 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-foundation 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-graphics 0.17.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "foreign-types 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+ "objc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "constant_time_eq"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "core-foundation"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "core-foundation-sys 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "core-foundation-sys"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "core-graphics"
+version = "0.17.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-foundation 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "foreign-types 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "crc32fast"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.6.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "deflate"
+version = "0.7.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "adler32 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "dirs"
+version = "2.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "dirs-sys 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "dirs-sys"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+ "redox_users 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "dlib"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libloading 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "downcast-rs"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "failure"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "backtrace 0.3.40 (registry+https://github.com/rust-lang/crates.io-index)",
+ "failure_derive 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "failure_derive"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "synstructure 0.12.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "fnv"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "foreign-types"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "foreign-types-shared 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "foreign-types-shared"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "fuchsia-cprng"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "getopts"
+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "unicode-width 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "getrandom"
+version = "0.1.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasi 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "gl_generator"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "khronos_api 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "xml-rs 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "gl_generator"
+version = "0.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "khronos_api 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "xml-rs 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "gleam"
+version = "0.6.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "gl_generator 0.13.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "glium"
+version = "0.24.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "backtrace 0.3.40 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "gl_generator 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "glutin 0.20.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "smallvec 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "glob"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "glutin"
+version = "0.20.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "android_glue 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cgl 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cocoa 0.18.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-foundation 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-graphics 0.17.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "glutin_egl_sys 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "glutin_gles2_sys 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "glutin_glx_sys 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "glutin_wgl_sys 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libloading 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "objc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "osmesa-sys 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "shared_library 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-client 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winit 0.19.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "glutin_egl_sys"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "gl_generator 0.13.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "glutin_gles2_sys"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "gl_generator 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "objc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "glutin_glx_sys"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "gl_generator 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "x11-dl 2.18.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "glutin_wgl_sys"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "gl_generator 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "inflate"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "adler32 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "khronos_api"
+version = "3.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "libc"
+version = "0.2.65"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "libloading"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cc 1.0.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "line_drawing"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "num-traits 0.2.9 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "lock_api"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "scopeguard 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "log"
+version = "0.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "malloc_buf"
+version = "0.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "maybe-uninit"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "memmap"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "nix"
+version = "0.14.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cc 1.0.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+ "void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "nodrop"
+version = "0.1.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "num-traits"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "objc"
+version = "0.2.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "malloc_buf 0.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "ordered-float"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "num-traits 0.2.9 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "osmesa-sys"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "shared_library 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "parking_lot"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "lock_api 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parking_lot_core 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "parking_lot_core"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+ "redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "smallvec 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "percent-encoding"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "pkg-config"
+version = "0.3.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "png"
+version = "0.15.3"
+dependencies = [
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crc32fast 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "deflate 0.7.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "getopts 0.2.21 (registry+https://github.com/rust-lang/crates.io-index)",
+ "glium 0.24.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "glob 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "inflate 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "term 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "ppv-lite86"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "proc-macro2"
+version = "0.4.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "quote"
+version = "0.6.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "getrandom 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_chacha 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_hc 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "c2-chacha 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "rand_core"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "getrandom 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_os"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "raw-window-handle"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rdrand"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "redox_syscall"
+version = "0.1.56"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "redox_users"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "failure 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_os 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rust-argon2 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rust-argon2"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "base64 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "blake2b_simd 0.5.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-utils 0.6.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rustc-demangle"
+version = "0.1.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "rustc_version"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rusttype"
+version = "0.7.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rusttype 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rusttype"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "approx 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "arrayvec 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ordered-float 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "stb_truetype 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "same-file"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi-util 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "scopeguard"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "semver"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "semver-parser"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "shared_library"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "smallvec"
+version = "0.6.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "smithay-client-toolkit"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "andrew 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "dlib 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memmap 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "nix 0.14.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-client 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-commons 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-protocols 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "stb_truetype"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "syn"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "synstructure"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "term"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "dirs 2.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "unicode-width"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "unicode-xid"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "unicode-xid"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "void"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "walkdir"
+version = "2.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "same-file 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-util 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wasi"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "wayland-client"
+version = "0.21.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "downcast-rs 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+ "nix 0.14.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-commons 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-scanner 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-sys 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wayland-commons"
+version = "0.21.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "nix 0.14.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-sys 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wayland-protocols"
+version = "0.21.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-client 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-commons 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-scanner 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-sys 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wayland-scanner"
+version = "0.21.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "xml-rs 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wayland-sys"
+version = "0.21.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "dlib 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "winapi"
+version = "0.3.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "winapi-util"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "winit"
+version = "0.19.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "android_glue 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "backtrace 0.3.40 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cocoa 0.18.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-foundation 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "core-graphics 0.17.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "objc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "percent-encoding 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "raw-window-handle 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "smithay-client-toolkit 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wayland-client 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+ "x11-dl 2.18.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "x11-dl"
+version = "2.18.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)",
+ "maybe-uninit 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "pkg-config 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "xdg"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "xml-rs"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[metadata]
+"checksum adler32 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "5d2e7343e7fc9de883d1b0341e0b13970f764c14101234857d2ddafa1cb1cac2"
+"checksum andrew 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9b7f09f89872c2b6b29e319377b1fbe91c6f5947df19a25596e121cf19a7b35e"
+"checksum android_glue 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "000444226fcff248f2bc4c7625be32c63caccfecc2723a2b9f78a7487a49c407"
+"checksum approx 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f0e60b75072ecd4168020818c0107f2857bb6c4e64252d8d3983f6263b40a5c3"
+"checksum arrayref 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "0d382e583f07208808f6b1249e60848879ba3543f57c32277bf52d69c2f0f0ee"
+"checksum arrayvec 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)" = "cd9fd44efafa8690358b7408d253adf110036b88f55672a933f01d616ad9b1b9"
+"checksum arrayvec 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cff77d8686867eceff3105329d4698d96c2391c176d5d03adc90c7389162b5b8"
+"checksum autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "1d49d90015b3c36167a20fe2810c5cd875ad504b39cff3d4eae7977e6b7c1cb2"
+"checksum backtrace 0.3.40 (registry+https://github.com/rust-lang/crates.io-index)" = "924c76597f0d9ca25d762c25a4d369d51267536465dc5064bdf0eb073ed477ea"
+"checksum backtrace-sys 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)" = "5d6575f128516de27e3ce99689419835fce9643a9b215a14d2b5b685be018491"
+"checksum base64 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0b25d992356d2eb0ed82172f5248873db5560c4721f564b13cb5193bda5e668e"
+"checksum bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
+"checksum blake2b_simd 0.5.8 (registry+https://github.com/rust-lang/crates.io-index)" = "5850aeee1552f495dd0250014cf64b82b7c8879a89d83b33bbdace2cc4f63182"
+"checksum block 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "0d8c1fef690941d3e7788d328517591fecc684c084084702d6ff1641e993699a"
+"checksum byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a7c3dd8985a7111efc5c80b44e23ecdd8c007de8ade3b96595387e812b957cf5"
+"checksum c2-chacha 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "214238caa1bf3a496ec3392968969cab8549f96ff30652c9e56885329315f6bb"
+"checksum cc 1.0.46 (registry+https://github.com/rust-lang/crates.io-index)" = "0213d356d3c4ea2c18c40b037c3be23cd639825c18f25ee670ac7813beeef99c"
+"checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
+"checksum cgl 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "55e7ec0b74fe5897894cbc207092c577e87c52f8a59e8ca8d97ef37551f60a49"
+"checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
+"checksum cocoa 0.18.5 (registry+https://github.com/rust-lang/crates.io-index)" = "1706996401131526e36b3b49f0c4d912639ce110996f3ca144d78946727bce54"
+"checksum constant_time_eq 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "995a44c877f9212528ccc74b21a232f66ad69001e40ede5bcee2ac9ef2657120"
+"checksum core-foundation 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)" = "25b9e03f145fd4f2bf705e07b900cd41fc636598fe5dc452fd0db1441c3f496d"
+"checksum core-foundation-sys 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e7ca8a5221364ef15ce201e8ed2f609fc312682a8f4e0e3d4aa5879764e0fa3b"
+"checksum core-graphics 0.17.3 (registry+https://github.com/rust-lang/crates.io-index)" = "56790968ab1c8a1202a102e6de05fc6e1ec87da99e4e93e9a7d13efbfc1e95a9"
+"checksum crc32fast 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ba125de2af0df55319f41944744ad91c71113bf74a4646efff39afe1f6842db1"
+"checksum crossbeam-utils 0.6.6 (registry+https://github.com/rust-lang/crates.io-index)" = "04973fa96e96579258a5091af6003abde64af786b860f18622b82e026cca60e6"
+"checksum deflate 0.7.20 (registry+https://github.com/rust-lang/crates.io-index)" = "707b6a7b384888a70c8d2e8650b3e60170dfc6a67bb4aa67b6dfca57af4bedb4"
+"checksum dirs 2.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "13aea89a5c93364a98e9b37b2fa237effbb694d5cfe01c5b70941f7eb087d5e3"
+"checksum dirs-sys 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "afa0b23de8fd801745c471deffa6e12d248f962c9fd4b4c33787b055599bde7b"
+"checksum dlib 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "77e51249a9d823a4cb79e3eca6dcd756153e8ed0157b6c04775d04bf1b13b76a"
+"checksum downcast-rs 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5fe414cc2fd4447b7da94b27ddfb6831a8a06f35f6d077ab5613ec703866c49a"
+"checksum failure 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "f8273f13c977665c5db7eb2b99ae520952fe5ac831ae4cd09d80c4c7042b5ed9"
+"checksum failure_derive 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "0bc225b78e0391e4b8683440bf2e63c2deeeb2ce5189eab46e2b68c6d3725d08"
+"checksum fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "2fad85553e09a6f881f739c29f0b00b0f01357c743266d478b68951ce23285f3"
+"checksum foreign-types 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f6f339eb8adc052cd2ca78910fda869aefa38d22d5cb648e6485e4d3fc06f3b1"
+"checksum foreign-types-shared 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "00b0228411908ca8685dba7fc2cdd70ec9990a6e753e89b6ac91a84c40fbaf4b"
+"checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
+"checksum getopts 0.2.21 (registry+https://github.com/rust-lang/crates.io-index)" = "14dbbfd5c71d70241ecf9e6f13737f7b5ce823821063188d7e46c41d371eebd5"
+"checksum getrandom 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "e7db7ca94ed4cd01190ceee0d8a8052f08a247aa1b469a7f68c6a3b71afcf407"
+"checksum gl_generator 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "39a23d5e872a275135d66895d954269cf5e8661d234eb1c2480f4ce0d586acbd"
+"checksum gl_generator 0.13.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ca98bbde17256e02d17336a6bdb5a50f7d0ccacee502e191d3e3d0ec2f96f84a"
+"checksum gleam 0.6.19 (registry+https://github.com/rust-lang/crates.io-index)" = "cae10d7c99d0e77b4766e850a60898a17c1abaf01075531f1066f03dc7dc5fc5"
+"checksum glium 0.24.0 (registry+https://github.com/rust-lang/crates.io-index)" = "213290166315d0ff3cf48dd76a31f3ad57c934182d3e87aeec890f2747226a21"
+"checksum glob 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
+"checksum glutin 0.20.1 (registry+https://github.com/rust-lang/crates.io-index)" = "6e5cc17ac6cb35704f434faaa5bb5e4254a66f50853976c7e6f00aee09ff1bf2"
+"checksum glutin_egl_sys 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "772edef3b28b8ad41e4ea202748e65eefe8e5ffd1f4535f1219793dbb20b3d4c"
+"checksum glutin_gles2_sys 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "89996c30857ae1b4de4b5189abf1ea822a20a9fe9e1c93e5e7b862ff0bdd5cdf"
+"checksum glutin_glx_sys 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "1290a5ca5e46fcfa7f66f949cc9d9194b2cb6f2ed61892c8c2b82343631dba57"
+"checksum glutin_wgl_sys 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "f801bbc91efc22dd1c4818a47814fc72bf74d024510451b119381579bfa39021"
+"checksum inflate 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)" = "1cdb29978cc5797bd8dcc8e5bf7de604891df2a8dc576973d71a281e916db2ff"
+"checksum khronos_api 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2db585e1d738fc771bf08a151420d3ed193d9d895a36df7f6f8a9456b911ddc"
+"checksum lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+"checksum libc 0.2.65 (registry+https://github.com/rust-lang/crates.io-index)" = "1a31a0627fdf1f6a39ec0dd577e101440b7db22672c0901fe00a9a6fbb5c24e8"
+"checksum libloading 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f2b111a074963af1d37a139918ac6d49ad1d0d5e47f72fd55388619691a7d753"
+"checksum line_drawing 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5cc7ad3d82c845bdb5dde34ffdcc7a5fb4d2996e1e1ee0f19c33bc80e15196b9"
+"checksum lock_api 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f8912e782533a93a167888781b836336a6ca5da6175c05944c86cf28c31104dc"
+"checksum log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)" = "14b6052be84e6b71ab17edffc2eeabf5c2c3ae1fdb464aae35ac50c67a44e1f7"
+"checksum malloc_buf 0.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "62bb907fe88d54d8d9ce32a3cceab4218ed2f6b7d35617cafe9adf84e43919cb"
+"checksum maybe-uninit 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "60302e4db3a61da70c0cb7991976248362f30319e88850c487b9b95bbf059e00"
+"checksum memmap 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6585fd95e7bb50d6cc31e20d4cf9afb4e2ba16c5846fc76793f11218da9c475b"
+"checksum nix 0.14.1 (registry+https://github.com/rust-lang/crates.io-index)" = "6c722bee1037d430d0f8e687bbdbf222f27cc6e4e68d5caf630857bb2b6dbdce"
+"checksum nodrop 0.1.14 (registry+https://github.com/rust-lang/crates.io-index)" = "72ef4a56884ca558e5ddb05a1d1e7e1bfd9a68d9ed024c21704cc98872dae1bb"
+"checksum num-traits 0.2.9 (registry+https://github.com/rust-lang/crates.io-index)" = "443c53b3c3531dfcbfa499d8893944db78474ad7a1d87fa2d94d1a2231693ac6"
+"checksum objc 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "915b1b472bc21c53464d6c8461c9d3af805ba1ef837e1cac254428f4a77177b1"
+"checksum ordered-float 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "18869315e81473c951eb56ad5558bbc56978562d3ecfb87abb7a1e944cea4518"
+"checksum osmesa-sys 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "88cfece6e95d2e717e0872a7f53a8684712ad13822a7979bc760b9c77ec0013b"
+"checksum parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f842b1982eb6c2fe34036a4fbfb06dd185a3f5c8edfaacdf7d1ea10b07de6252"
+"checksum parking_lot_core 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "b876b1b9e7ac6e1a74a6da34d25c42e17e8862aa409cbbbdcfc8d86c6f3bc62b"
+"checksum percent-encoding 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d4fd5641d01c8f18a23da7b6fe29298ff4b55afcccdf78973b24cf3175fee32e"
+"checksum pkg-config 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)" = "72d5370d90f49f70bd033c3d75e87fc529fbfff9d6f7cccef07d6170079d91ea"
+"checksum ppv-lite86 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "74490b50b9fbe561ac330df47c08f3f33073d2d00c150f719147d7c54522fa1b"
+"checksum proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)" = "cf3d2011ab5c909338f7887f4fc896d35932e29146c12c8d01da6b22a80ba759"
+"checksum proc-macro2 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "9c9e470a8dc4aeae2dee2f335e8f533e2d4b347e1434e5671afc49b054592f27"
+"checksum quote 0.6.13 (registry+https://github.com/rust-lang/crates.io-index)" = "6ce23b6b870e8f94f81fb0a363d65d86675884b34a09043c81e5562f11c1f8e1"
+"checksum quote 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "053a8c8bcc71fcce321828dc897a98ab9760bef03a4fc36693c231e5b3216cfe"
+"checksum rand 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "3ae1b169243eaf61759b8475a998f0a385e42042370f3a7dbaf35246eacc8412"
+"checksum rand_chacha 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "03a2a90da8c7523f554344f921aa97283eadf6ac484a6d2a7d0212fa7f8d6853"
+"checksum rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
+"checksum rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9c33a3c44ca05fa6f1807d8e6743f3824e8509beca625669633be0acbdf509dc"
+"checksum rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
+"checksum rand_hc 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
+"checksum rand_os 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "7b75f676a1e053fc562eafbb47838d67c84801e38fc1ba459e8f180deabd5071"
+"checksum raw-window-handle 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9db80d08d3ed847ce4fb3def46de0af4bfb6155bd09bd6eaf28b5ac72541c1f1"
+"checksum rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
+"checksum redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)" = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84"
+"checksum redox_users 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "4ecedbca3bf205f8d8f5c2b44d83cd0690e39ee84b951ed649e9f1841132b66d"
+"checksum rust-argon2 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "4ca4eaef519b494d1f2848fc602d18816fed808a981aedf4f1f00ceb7c9d32cf"
+"checksum rustc-demangle 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)" = "4c691c0e608126e00913e33f0ccf3727d5fc84573623b8d65b2df340b5201783"
+"checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
+"checksum rusttype 0.7.9 (registry+https://github.com/rust-lang/crates.io-index)" = "310942406a39981bed7e12b09182a221a29e0990f3e7e0c971f131922ed135d5"
+"checksum rusttype 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "6fa38506b5cbf2fb67f915e2725cb5012f1b9a785b0ab55c4733acda5f6554ef"
+"checksum same-file 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "585e8ddcedc187886a30fa705c47985c3fa88d06624095856b36ca0b82ff4421"
+"checksum scopeguard 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b42e15e59b18a828bbf5c58ea01debb36b9b096346de35d941dcb89009f24a0d"
+"checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
+"checksum semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
+"checksum shared_library 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "5a9e7e0f2bfae24d8a5b5a66c5b257a83c7412304311512a0c054cd5e619da11"
+"checksum smallvec 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)" = "ab606a9c5e214920bb66c458cd7be8ef094f813f20fe77a54cc7dbfff220d4b7"
+"checksum smithay-client-toolkit 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "2ccb8c57049b2a34d2cc2b203fa785020ba0129d31920ef0d317430adaf748fa"
+"checksum stb_truetype 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "824210d6fb52cbc3ad2545270ead6860c7311aa5450642b078da4515937b6f7a"
+"checksum syn 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "66850e97125af79138385e9b88339cbcd037e3f28ceab8c5ad98e64f0f1f80bf"
+"checksum synstructure 0.12.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3f085a5855930c0441ca1288cf044ea4aecf4f43a91668abdb870b4ba546a203"
+"checksum term 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c0863a3345e70f61d613eab32ee046ccd1bcc5f9105fe402c61fcd0c13eeb8b5"
+"checksum unicode-width 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "7007dbd421b92cc6e28410fe7362e2e0a2503394908f417b68ec8d1c364c4e20"
+"checksum unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"
+"checksum unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "826e7639553986605ec5979c7dd957c7895e93eabed50ab2ffa7f6128a75097c"
+"checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
+"checksum walkdir 2.2.9 (registry+https://github.com/rust-lang/crates.io-index)" = "9658c94fa8b940eab2250bd5a457f9c48b748420d71293b165c8cdbe2f55f71e"
+"checksum wasi 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b89c3ce4ce14bdc6fb6beaf9ec7928ca331de5df7e5ea278375642a2f478570d"
+"checksum wayland-client 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)" = "49963e5f9eeaf637bfcd1b9f0701c99fd5cd05225eb51035550d4272806f2713"
+"checksum wayland-commons 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)" = "40c08896768b667e1df195d88a62a53a2d1351a1ed96188be79c196b35bb32ec"
+"checksum wayland-protocols 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)" = "4afde2ea2a428eee6d7d2c8584fdbe8b82eee8b6c353e129a434cd6e07f42145"
+"checksum wayland-scanner 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)" = "bf3828c568714507315ee425a9529edc4a4aa9901409e373e9e0027e7622b79e"
+"checksum wayland-sys 0.21.13 (registry+https://github.com/rust-lang/crates.io-index)" = "520ab0fd578017a0ee2206623ba9ef4afe5e8f23ca7b42f6acfba2f4e66b1628"
+"checksum winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"
+"checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+"checksum winapi-util 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7168bab6e1daee33b4557efd0e95d5ca70a03706d39fa5f3fe7a236f584b03c9"
+"checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
+"checksum winit 0.19.5 (registry+https://github.com/rust-lang/crates.io-index)" = "1e96eb4bb472fa43e718e8fa4aef82f86cd9deac9483a1e1529230babdb394a8"
+"checksum x11-dl 2.18.4 (registry+https://github.com/rust-lang/crates.io-index)" = "be65e1342a3baae65439cd03306778831a3d133b0d20243a7fb83fd5cf403c58"
+"checksum xdg 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d089681aa106a86fade1b0128fb5daf07d5867a509ab036d99988dec80429a57"
+"checksum xml-rs 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "541b12c998c5b56aa2b4e6f18f03664eef9a4fd0a246a55594efae6cc2d964b5"
diff --git a/third_party/rust/png/Cargo.toml b/third_party/rust/png/Cargo.toml
new file mode 100644
index 0000000000..2e57fab7fe
--- /dev/null
+++ b/third_party/rust/png/Cargo.toml
@@ -0,0 +1,56 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies
+#
+# If you believe there's an error in this file please file an
+# issue against the rust-lang/cargo repository. If you're
+# editing this file be aware that the upstream Cargo.toml
+# will likely look very different (and much more reasonable)
+
+[package]
+edition = "2018"
+name = "png"
+version = "0.15.3"
+authors = ["nwin <nwin@users.noreply.github.com>"]
+exclude = ["tests/*"]
+description = "PNG decoding and encoding library in pure Rust"
+categories = ["multimedia::images"]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/image-rs/image-png.git"
+[dependencies.bitflags]
+version = "1.0"
+
+[dependencies.crc32fast]
+version = "1.2.0"
+
+[dependencies.deflate]
+version = "0.7.12"
+optional = true
+
+[dependencies.inflate]
+version = "0.4.2"
+[dev-dependencies.getopts]
+version = "0.2.14"
+
+[dev-dependencies.glium]
+version = "0.24"
+features = ["glutin"]
+default-features = false
+
+[dev-dependencies.glob]
+version = "0.3"
+
+[dev-dependencies.rand]
+version = "0.7.0"
+
+[dev-dependencies.term]
+version = "0.6.1"
+
+[features]
+benchmarks = []
+default = ["png-encoding"]
+png-encoding = ["deflate"]
+unstable = []
diff --git a/third_party/rust/png/Dockerfile b/third_party/rust/png/Dockerfile
new file mode 100644
index 0000000000..780e28c09b
--- /dev/null
+++ b/third_party/rust/png/Dockerfile
@@ -0,0 +1,5 @@
+FROM rustlang/rust:nightly
+WORKDIR /image-png
+COPY . .
+RUN cargo install cargo-fuzz
+RUN cargo fuzz run decode -- -runs=0
diff --git a/third_party/rust/png/LICENSE-APACHE b/third_party/rust/png/LICENSE-APACHE
new file mode 100644
index 0000000000..16fe87b06e
--- /dev/null
+++ b/third_party/rust/png/LICENSE-APACHE
@@ -0,0 +1,201 @@
+                              Apache License
+                        Version 2.0, January 2004
+                     http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+   "License" shall mean the terms and conditions for use, reproduction,
+   and distribution as defined by Sections 1 through 9 of this document.
+
+   "Licensor" shall mean the copyright owner or entity authorized by
+   the copyright owner that is granting the License.
+
+   "Legal Entity" shall mean the union of the acting entity and all
+   other entities that control, are controlled by, or are under common
+   control with that entity. For the purposes of this definition,
+   "control" means (i) the power, direct or indirect, to cause the
+   direction or management of such entity, whether by contract or
+   otherwise, or (ii) ownership of fifty percent (50%) or more of the
+   outstanding shares, or (iii) beneficial ownership of such entity.
+
+   "You" (or "Your") shall mean an individual or Legal Entity
+   exercising permissions granted by this License.
+
+   "Source" form shall mean the preferred form for making modifications,
+   including but not limited to software source code, documentation
+   source, and configuration files.
+
+   "Object" form shall mean any form resulting from mechanical
+   transformation or translation of a Source form, including but
+   not limited to compiled object code, generated documentation,
+   and conversions to other media types.
+
+   "Work" shall mean the work of authorship, whether in Source or
+   Object form, made available under the License, as indicated by a
+   copyright notice that is included in or attached to the work
+   (an example is provided in the Appendix below).
+
+   "Derivative Works" shall mean any work, whether in Source or Object
+   form, that is based on (or derived from) the Work and for which the
+   editorial revisions, annotations, elaborations, or other modifications
+   represent, as a whole, an original work of authorship. For the purposes
+   of this License, Derivative Works shall not include works that remain
+   separable from, or merely link (or bind by name) to the interfaces of,
+   the Work and Derivative Works thereof.
+
+   "Contribution" shall mean any work of authorship, including
+   the original version of the Work and any modifications or additions
+   to that Work or Derivative Works thereof, that is intentionally
+   submitted to Licensor for inclusion in the Work by the copyright owner
+   or by an individual or Legal Entity authorized to submit on behalf of
+   the copyright owner. For the purposes of this definition, "submitted"
+   means any form of electronic, verbal, or written communication sent
+   to the Licensor or its representatives, including but not limited to
+   communication on electronic mailing lists, source code control systems,
+   and issue tracking systems that are managed by, or on behalf of, the
+   Licensor for the purpose of discussing and improving the Work, but
+   excluding communication that is conspicuously marked or otherwise
+   designated in writing by the copyright owner as "Not a Contribution."
+
+   "Contributor" shall mean Licensor and any individual or Legal Entity
+   on behalf of whom a Contribution has been received by Licensor and
+   subsequently incorporated within the Work.
+
+2. Grant of Copyright License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   copyright license to reproduce, prepare Derivative Works of,
+   publicly display, publicly perform, sublicense, and distribute the
+   Work and such Derivative Works in Source or Object form.
+
+3. Grant of Patent License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   (except as stated in this section) patent license to make, have made,
+   use, offer to sell, sell, import, and otherwise transfer the Work,
+   where such license applies only to those patent claims licensable
+   by such Contributor that are necessarily infringed by their
+   Contribution(s) alone or by combination of their Contribution(s)
+   with the Work to which such Contribution(s) was submitted. If You
+   institute patent litigation against any entity (including a
+   cross-claim or counterclaim in a lawsuit) alleging that the Work
+   or a Contribution incorporated within the Work constitutes direct
+   or contributory patent infringement, then any patent licenses
+   granted to You under this License for that Work shall terminate
+   as of the date such litigation is filed.
+
+4. Redistribution. You may reproduce and distribute copies of the
+   Work or Derivative Works thereof in any medium, with or without
+   modifications, and in Source or Object form, provided that You
+   meet the following conditions:
+
+   (a) You must give any other recipients of the Work or
+       Derivative Works a copy of this License; and
+
+   (b) You must cause any modified files to carry prominent notices
+       stating that You changed the files; and
+
+   (c) You must retain, in the Source form of any Derivative Works
+       that You distribute, all copyright, patent, trademark, and
+       attribution notices from the Source form of the Work,
+       excluding those notices that do not pertain to any part of
+       the Derivative Works; and
+
+   (d) If the Work includes a "NOTICE" text file as part of its
+       distribution, then any Derivative Works that You distribute must
+       include a readable copy of the attribution notices contained
+       within such NOTICE file, excluding those notices that do not
+       pertain to any part of the Derivative Works, in at least one
+       of the following places: within a NOTICE text file distributed
+       as part of the Derivative Works; within the Source form or
+       documentation, if provided along with the Derivative Works; or,
+       within a display generated by the Derivative Works, if and
+       wherever such third-party notices normally appear. The contents
+       of the NOTICE file are for informational purposes only and
+       do not modify the License. You may add Your own attribution
+       notices within Derivative Works that You distribute, alongside
+       or as an addendum to the NOTICE text from the Work, provided
+       that such additional attribution notices cannot be construed
+       as modifying the License.
+
+   You may add Your own copyright statement to Your modifications and
+   may provide additional or different license terms and conditions
+   for use, reproduction, or distribution of Your modifications, or
+   for any such Derivative Works as a whole, provided Your use,
+   reproduction, and distribution of the Work otherwise complies with
+   the conditions stated in this License.
+
+5. Submission of Contributions. Unless You explicitly state otherwise,
+   any Contribution intentionally submitted for inclusion in the Work
+   by You to the Licensor shall be under the terms and conditions of
+   this License, without any additional terms or conditions.
+   Notwithstanding the above, nothing herein shall supersede or modify
+   the terms of any separate license agreement you may have executed
+   with Licensor regarding such Contributions.
+
+6. Trademarks. This License does not grant permission to use the trade
+   names, trademarks, service marks, or product names of the Licensor,
+   except as required for reasonable and customary use in describing the
+   origin of the Work and reproducing the content of the NOTICE file.
+
+7. Disclaimer of Warranty. Unless required by applicable law or
+   agreed to in writing, Licensor provides the Work (and each
+   Contributor provides its Contributions) on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+   implied, including, without limitation, any warranties or conditions
+   of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+   PARTICULAR PURPOSE. You are solely responsible for determining the
+   appropriateness of using or redistributing the Work and assume any
+   risks associated with Your exercise of permissions under this License.
+
+8. Limitation of Liability. In no event and under no legal theory,
+   whether in tort (including negligence), contract, or otherwise,
+   unless required by applicable law (such as deliberate and grossly
+   negligent acts) or agreed to in writing, shall any Contributor be
+   liable to You for damages, including any direct, indirect, special,
+   incidental, or consequential damages of any character arising as a
+   result of this License or out of the use or inability to use the
+   Work (including but not limited to damages for loss of goodwill,
+   work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses), even if such Contributor
+   has been advised of the possibility of such damages.
+
+9. Accepting Warranty or Additional Liability. While redistributing
+   the Work or Derivative Works thereof, You may choose to offer,
+   and charge a fee for, acceptance of support, warranty, indemnity,
+   or other liability obligations and/or rights consistent with this
+   License. However, in accepting such obligations, You may act only
+   on Your own behalf and on Your sole responsibility, not on behalf
+   of any other Contributor, and only if You agree to indemnify,
+   defend, and hold each Contributor harmless for any liability
+   incurred by, or claims asserted against, such Contributor by reason
+   of your accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
+
+APPENDIX: How to apply the Apache License to your work.
+
+   To apply the Apache License to your work, attach the following
+   boilerplate notice, with the fields enclosed by brackets "[]"
+   replaced with your own identifying information. (Don't include
+   the brackets!)  The text should be enclosed in the appropriate
+   comment syntax for the file format. We also recommend that a
+   file or class name and description of purpose be included on the
+   same "printed page" as the copyright notice for easier
+   identification within third-party archives.
+
+Copyright [yyyy] [name of copyright owner]
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
diff --git a/third_party/rust/png/LICENSE-MIT b/third_party/rust/png/LICENSE-MIT
new file mode 100644
index 0000000000..ea471f02b7
--- /dev/null
+++ b/third_party/rust/png/LICENSE-MIT
@@ -0,0 +1,25 @@
+Copyright (c) 2015 nwin
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/third_party/rust/png/README.md b/third_party/rust/png/README.md
new file mode 100644
index 0000000000..abcceb6a32
--- /dev/null
+++ b/third_party/rust/png/README.md
@@ -0,0 +1,39 @@
+# PNG Decoder/Encoder
+[![Build Status](https://travis-ci.org/image-rs/image-png.svg?branch=master)](https://travis-ci.org/image-rs/image-png)
+[![Documentation](https://docs.rs/png/badge.svg)](https://docs.rs/png)
+[![Crates.io](https://img.shields.io/crates/v/png.svg)](https://crates.io/crates/png)
+![Lines of Code](https://tokei.rs/b1/github/image-rs/image-png)
+[![License](https://img.shields.io/crates/l/png.svg)](https://github.com/image-rs/image-png)
+[![fuzzit](https://app.fuzzit.dev/badge?org_id=image-rs)](https://app.fuzzit.dev/orgs/image-rs/dashboard)
+
+PNG decoder/encoder in pure Rust.
+
+It contains all features required to handle the entirety of [the PngSuite by
+Willem van Schack][PngSuite].
+
+[PngSuite]: http://www.schaik.com/pngsuite2011/pngsuite.html
+
+## pngcheck
+
+The `pngcheck` utility is a small demonstration binary that checks and prints
+metadata on every `.png` image provided via parameter. You can run it (for
+example on the test directories) with
+
+```bash
+cargo run --release --example pngcheck ./tests/pngsuite/*
+```
+
+## License
+
+Licensed under either of
+
+ * Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+ * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
+
+at your option.
+
+### Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any
+additional terms or conditions.
diff --git a/third_party/rust/png/benches/README.md b/third_party/rust/png/benches/README.md
new file mode 100644
index 0000000000..bf13a5544a
--- /dev/null
+++ b/third_party/rust/png/benches/README.md
@@ -0,0 +1,6 @@
+# Getting started with benchmarking
+
+To run the benchmarks you need a nightly rust toolchain.
+Then you launch it with
+
+    rustup run nightly cargo bench --features=benchmarks
diff --git a/third_party/rust/png/benches/decoder.rs b/third_party/rust/png/benches/decoder.rs
new file mode 100644
index 0000000000..7d9cce933c
--- /dev/null
+++ b/third_party/rust/png/benches/decoder.rs
@@ -0,0 +1,25 @@
+#![cfg(feature = "benchmarks")]

+#![feature(test)]

+

+extern crate png;

+extern crate test;

+

+use std::fs::File;

+use std::io::Read;

+

+use png::Decoder;

+

+#[bench]

+fn bench_big(b: &mut test::Bencher) {

+    let mut data = Vec::new();

+    File::open("tests/pngsuite/PngSuite.png").unwrap().read_to_end(&mut data).unwrap();

+    let decoder = Decoder::new(&*data);

+    let (info, _) = decoder.read_info().unwrap();

+    let mut image = vec![0; info.buffer_size()];

+    b.iter(|| {

+        let decoder = Decoder::new(&*data);

+        let (_, mut decoder) = decoder.read_info().unwrap();

+        test::black_box(decoder.next_frame(&mut image)).unwrap();

+    });

+    b.bytes = info.buffer_size() as u64

+}

diff --git a/third_party/rust/png/examples/pngcheck.rs b/third_party/rust/png/examples/pngcheck.rs
new file mode 100644
index 0000000000..6cd0b5b7e2
--- /dev/null
+++ b/third_party/rust/png/examples/pngcheck.rs
@@ -0,0 +1,360 @@
+#![allow(non_upper_case_globals)]
+
+extern crate getopts;
+extern crate glob;
+extern crate png;
+
+use std::io;
+use std::io::prelude::*;
+use std::path::Path;
+use std::fs::File;
+use std::env;
+
+use getopts::{Matches, Options, ParsingStyle};
+use term::{color, Attr};
+
+fn parse_args() -> Matches {
+    let args: Vec<String> = env::args().collect();
+    let mut opts = Options::new();
+    opts.optflag("c", "", "colorize output (for ANSI terminals)")
+        .optflag("q", "", "test quietly (output only errors)")
+        //.optflag("t", "", "print contents of tEXt chunks (can be used with -q)");
+        .optflag("v", "", "test verbosely (print most chunk data)")
+        .parsing_style(ParsingStyle::StopAtFirstFree);
+    if args.len() > 1 {
+        match opts.parse(&args[1..]) {
+            Ok(matches) => return matches,
+            Err(err) => println!("{}", err)
+        }
+    }
+    println!("{}", opts.usage(&format!("Usage: pngcheck [-cpt] [file ...]")));
+    std::process::exit(0);
+}
+
+#[derive(Clone, Copy)]
+struct Config {
+    quiet: bool,
+    verbose: bool,
+    color: bool
+}
+
+fn display_interlaced(i: bool) -> &'static str {
+    if i {
+        "interlaced"
+    } else {
+        "non-interlaced"
+    }
+}
+
+fn display_image_type(bits: u8, color: png::ColorType) -> String {
+    use png::ColorType::*;
+    format!(
+        "{}-bit {}",
+        bits,
+        match color {
+            Grayscale => "grayscale",
+            RGB => "RGB",
+            Indexed => "palette",
+            GrayscaleAlpha => "grayscale+alpha",
+            RGBA => "RGB+alpha"
+        }
+    )
+}
+// channels after expansion of tRNS
+fn final_channels(c: png::ColorType, trns: bool) -> u8 {
+    use png::ColorType::*;
+    match c {
+        Grayscale => 1 + if trns { 1 } else { 0 },
+        RGB => 3,
+        Indexed => 3 + if trns { 1 } else { 0 },
+        GrayscaleAlpha => 2,
+        RGBA => 4
+    }
+}
+fn check_image<P: AsRef<Path>>(c: Config, fname: P) -> io::Result<()> {
+    // TODO improve performance by resusing allocations from decoder
+    use png::Decoded::*;
+    let mut t = term::stdout().ok_or(io::Error::new(
+        io::ErrorKind::Other,
+        "could not open terminal"
+    ))?;
+    let mut data = vec![0; 10*1024];
+    let data_p = data.as_mut_ptr();
+    let mut reader = io::BufReader::new(File::open(&fname)?);
+    let fname = fname.as_ref().to_string_lossy();
+    let n = reader.read(&mut data)?;
+    let mut buf = &data[..n];
+    let mut pos = 0;
+    let mut decoder = png::StreamingDecoder::new();
+    // Image data
+    let mut width = 0;
+    let mut height = 0;
+    let mut color = png::ColorType::Grayscale;
+    let mut bits = 0;
+    let mut trns = false;
+    let mut interlaced = false;
+    let mut compressed_size = 0;
+    let mut n_chunks = 0;
+    let mut have_idat = false;
+    macro_rules! c_ratio(
+        // TODO add palette entries to compressed_size
+        () => ({
+            compressed_size as f32/(
+                height as u64 *
+                (width as u64 * final_channels(color, trns) as u64 * bits as u64 + 7)>>3
+            ) as f32
+        });
+    );
+    let display_error = |err| -> Result<_, io::Error> {
+        let mut t = term::stdout().ok_or(io::Error::new(
+            io::ErrorKind::Other,
+            "could not open terminal"
+        ))?;
+        if c.verbose {
+            if c.color {
+                print!(": ");
+                t.fg(color::RED)?;
+                writeln!(t, "{}", err)?;
+                t.attr(Attr::Bold)?;
+                write!(t, "ERRORS DETECTED")?;
+                t.reset()?;
+            } else {
+                println!(": {}", err);
+                print!("ERRORS DETECTED")
+            }
+            println!(" in {}", fname);
+        } else {
+            if !c.quiet { if c.color {
+                t.fg(color::RED)?;
+                t.attr(Attr::Bold)?;
+                write!(t, "ERROR")?;
+                t.reset()?;
+                write!(t, ": ")?;
+                t.fg(color::YELLOW)?;
+                writeln!(t, "{}", fname)?;
+                t.reset()?;
+            } else {
+                println!("ERROR: {}", fname)
+            }}
+            print!("{}: ", fname);
+            if c.color {
+                t.fg(color::RED)?;
+                writeln!(t, "{}", err)?;
+                t.reset()?;
+            } else {
+                println!("{}", err);
+            }
+            
+        }
+        Ok(())
+    };
+    
+    if c.verbose {
+        print!("File: ");
+        if c.color {
+            t.attr(Attr::Bold)?;
+            write!(t, "{}", fname)?;
+            t.reset()?;
+        } else {
+            print!("{}", fname);
+        }
+        print!(" ({}) bytes", data.len())
+            
+    }
+    loop {
+        if buf.len() == 0 {
+            // circumvent borrow checker
+            assert!(!data.is_empty());
+            let n = reader.read(unsafe {
+                ::std::slice::from_raw_parts_mut(data_p, data.len())
+            })?;
+
+            // EOF
+            if n == 0 {
+                println!("ERROR: premature end of file {}", fname);
+                break;
+            }
+            buf = &data[..n];
+        }
+        match decoder.update(buf, &mut Vec::new()) {
+            Ok((_, ImageEnd)) => {
+                if !have_idat {
+                    display_error(png::DecodingError::Format("IDAT chunk missing".into()))?;
+                    break;
+                }
+                if !c.verbose && !c.quiet {
+                    if c.color {
+                        t.fg(color::GREEN)?;
+                        t.attr(Attr::Bold)?;
+                        write!(t, "OK")?;
+                        t.reset()?;
+                        write!(t, ": ")?;
+                        t.fg(color::YELLOW)?;
+                        write!(t, "{}", fname)?;
+                        t.reset()?;
+                    } else {
+                        print!("OK: {}", fname)
+                    }
+                    println!(
+                        " ({}x{}, {}{}, {}, {:.1}%)",
+                        width,
+                        height,
+                        display_image_type(bits, color),
+                        (if trns { "+trns" } else { "" }),
+                        display_interlaced(interlaced),
+                        100.0*(1.0-c_ratio!())
+                    )
+                } else if !c.quiet {
+                    println!("");
+                    if c.color {
+                        t.fg(color::GREEN)?;
+                        t.attr(Attr::Bold)?;
+                        write!(t, "No errors detected ")?;
+                        t.reset()?;
+                    } else {
+                        print!("No errors detected ");
+                    }
+                    println!(
+                        "in {} ({} chunks, {:.1}% compression)",
+                        fname,
+                        n_chunks,
+                        100.0*(1.0-c_ratio!())
+                    )
+                }
+                break
+            },
+            Ok((n, res)) => {
+                buf = &buf[n..];
+                pos += n;
+                match res {
+                    Header(w, h, b, c, i) => {
+                        width = w;
+                        height = h;
+                        bits = b as u8;
+                        color = c;
+                        interlaced = i;
+                    }
+                    ChunkBegin(len, type_str) => {
+                        use png::chunk;
+                        n_chunks += 1;
+                        if c.verbose {
+                            let chunk = String::from_utf8_lossy(&type_str);
+                            println!("");
+                            print!("  chunk ");
+                            if c.color {
+                                t.fg(color::YELLOW)?;
+                                write!(t, "{}", chunk)?;
+                                t.reset()?;
+                            } else {
+                                print!("{}", chunk)
+                            }
+                            print!(
+                                " at offset {:#07x}, length {}",
+                                pos - 4, // substract chunk name length
+                                len
+                            )
+                        }
+                        match type_str {
+                            chunk::IDAT => {
+                                have_idat = true;
+                                compressed_size += len
+                            },
+                            chunk::tRNS => {
+                                trns = true;
+                            },    
+                            _ => ()
+                        }
+                    }
+                    ImageData => {
+                        //println!("got {} bytes of image data", data.len())
+                    }
+                    ChunkComplete(_, type_str) if c.verbose => {
+                        use png::chunk::*;
+                        match type_str {
+                            IHDR => {
+                                println!("");
+                                print!(
+                                    "    {} x {} image, {}{}, {}",
+                                    width,
+                                    height,
+                                    display_image_type(bits, color),
+                                    (if trns { "+trns" } else { "" }),
+                                    display_interlaced(interlaced),
+                                );
+                            }
+                            _ => ()
+                        }
+                    }
+                    AnimationControl(actl) => {
+                        println!("");
+                        print!(
+                            "    {} frames, {} plays",
+                            actl.num_frames,
+                            actl.num_plays,
+                        );
+                    }
+                    FrameControl(fctl) => {
+                        println!("");
+                        println!(
+                            "    sequence #{}, {} x {} pixels @ ({}, {})",
+                            fctl.sequence_number,
+                            fctl.width,
+                            fctl.height,
+                            fctl.x_offset,
+                            fctl.y_offset,
+                            /*fctl.delay_num,
+                            fctl.delay_den,
+                            fctl.dispose_op,
+                            fctl.blend_op,*/
+                        );
+                        print!(
+                            "    {}/{} s delay, dispose: {}, blend: {}",
+                            fctl.delay_num,
+                            if fctl.delay_den == 0 { 100 } else {fctl.delay_den},
+                            fctl.dispose_op,
+                            fctl.blend_op,
+                        );
+                    }
+                    _ => ()
+                }
+                //println!("{} {:?}", n, res)
+            },
+            Err(err) => {
+                let _ = display_error(err);
+                break
+            }
+        }
+    }
+    Ok(())
+}
+
+fn main() {
+    let m = parse_args();
+
+    let config = Config {
+        quiet: m.opt_present("q"),
+        verbose: m.opt_present("v"),
+        color: m.opt_present("c")
+    };
+
+    for file in m.free {
+        let result = if file.contains("*") {
+            glob::glob(&file).map_err(|err| {
+                io::Error::new(io::ErrorKind::Other, err)
+            }).and_then(|mut glob| glob.try_for_each(|entry| {
+                entry.map_err(|err| {
+                    io::Error::new(io::ErrorKind::Other, err)
+                }).and_then(|file| {
+                    check_image(config, file)
+                })
+            }))
+        } else {
+            check_image(config, &file)
+        };
+
+        result.unwrap_or_else(|err| {
+            println!("{}: {}", file, err);
+            std::process::exit(1)
+        });
+    }
+}
diff --git a/third_party/rust/png/examples/show.rs b/third_party/rust/png/examples/show.rs
new file mode 100644
index 0000000000..9185b8f77e
--- /dev/null
+++ b/third_party/rust/png/examples/show.rs
@@ -0,0 +1,199 @@
+extern crate glium;
+extern crate glob;
+extern crate png;
+
+use std::env;
+use std::io;
+use std::fs::File;
+use std::borrow::Cow;
+use std::path;
+use std::error::Error;
+
+use glium::{Surface, Rect, BlitTarget};
+use glium::texture::{RawImage2d, ClientFormat};
+use glium::glutin::{self, Event, VirtualKeyCode, dpi};
+use glium::backend::glutin::Display;
+
+/// Load the image using `png`
+fn load_image(path: &path::PathBuf) -> io::Result<RawImage2d<'static, u8>> {
+    use png::ColorType::*;
+    let decoder = png::Decoder::new(File::open(path)?);
+    let (info, mut reader) = decoder.read_info()?;
+    let mut img_data = vec![0; info.buffer_size()];
+    reader.next_frame(&mut img_data)?;
+
+    let (data, format) = match info.color_type {
+        RGB => (img_data, ClientFormat::U8U8U8),
+        RGBA => (img_data, ClientFormat::U8U8U8U8),
+        Grayscale => (
+            {
+                let mut vec = Vec::with_capacity(img_data.len()*3);
+                for g in img_data {
+                    vec.extend([g, g, g].iter().cloned())
+                }
+                vec
+            },
+            ClientFormat::U8U8U8
+        ),
+        GrayscaleAlpha => (
+            {
+                let mut vec = Vec::with_capacity(img_data.len()*3);
+                for ga in img_data.chunks(2) {
+                    let g = ga[0]; let a = ga[1];
+                    vec.extend([g, g, g, a].iter().cloned())
+                }
+                vec
+            },
+            ClientFormat::U8U8U8U8
+        ),
+        _ => unreachable!("uncovered color type")
+    };
+
+    Ok(RawImage2d {
+        data: Cow::Owned(data),
+        width: info.width,
+        height: info.height,
+        format: format
+    })
+}
+
+fn main_loop(files: Vec<path::PathBuf>) -> io::Result<()> {
+    use glium::glutin::{KeyboardInput, WindowEvent};
+
+    let mut files = files.iter();
+    let image = load_image(files.next().unwrap())?;
+
+    let mut events_loop = glutin::EventsLoop::new();
+    let window = glutin::WindowBuilder::new();
+    let context = glutin::ContextBuilder::new()
+        .with_vsync(true);
+
+    let display = Display::new(window, context, &events_loop)
+        .map_err(|err| io::Error::new(
+            io::ErrorKind::Other,
+            err.description()
+        ))?;
+    // building the display, ie. the main object
+    resize_window(&display, &image);
+    let mut opengl_texture = glium::Texture2d::new(&display, image).unwrap();
+
+    let mut stop = false;
+    let mut res = Ok(());
+    'main: loop {
+        let frame = display.draw();
+        fill_v_flipped(&opengl_texture.as_surface(), &frame, glium::uniforms::MagnifySamplerFilter::Linear);
+        frame.finish().unwrap();
+
+        // polling and handling the events received by the window
+        events_loop.poll_events(|event| {
+            if stop {return;}
+            match event {
+                Event::WindowEvent {event: WindowEvent::CloseRequested, ..} => {
+                    stop = true;
+                    return;
+                }
+                Event::WindowEvent {
+                    event: WindowEvent::KeyboardInput {
+                        input: KeyboardInput {
+                            state: glutin::ElementState::Pressed,
+                            virtual_keycode: code,
+                            ..
+                        },
+                        ..
+                    },
+                    ..
+                } => match code {
+                    Some(VirtualKeyCode::Escape) => {
+                        stop = true;
+                        return;
+                    }
+                    Some(VirtualKeyCode::Right) => {
+                        match files.next() {
+                            Some(path) => {
+                                let image = match load_image(path) {
+                                    Ok(image) => image,
+                                    Err(err) => {
+                                        stop = true;
+                                        res = Err(err);
+                                        return;
+                                    }
+                                };
+                                resize_window(&display, &image);
+                                opengl_texture = glium::Texture2d::new(&display, image).unwrap();
+                            },
+                            None => {
+                                stop = true;
+                                return;
+                            }
+                        }
+                    },
+                    _ => ()
+                },
+                _ => ()
+            }
+        });
+
+        if stop {break 'main;}
+    }
+    res
+}
+
+fn fill_v_flipped<S1, S2>(src: &S1, target: &S2, filter: glium::uniforms::MagnifySamplerFilter)
+where S1: Surface, S2: Surface {
+    let src_dim = src.get_dimensions();
+    let src_rect = Rect { left: 0, bottom: 0, width: src_dim.0 as u32, height: src_dim.1 as u32 };
+    let target_dim = target.get_dimensions();
+    let target_rect = BlitTarget { left: 0, bottom: target_dim.1, width: target_dim.0 as i32, height: -(target_dim.1 as i32) };
+    src.blit_color(&src_rect, target, &target_rect, filter);
+}
+
+fn resize_window(display: &Display, image: &RawImage2d<'static, u8>) {
+    let mut width = image.width;
+    let mut height = image.height;
+    if width < 50 && height < 50 {
+        width *= 10;
+        height *= 10;
+    } else if width < 5 && height < 5 {
+        width *= 10;
+        height *= 10;
+    }
+    display.gl_window().window().set_inner_size(dpi::LogicalSize::new(f64::from(width), f64::from(height)));
+}
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+    if args.len() < 2 {
+        println!("Usage: show files [...]");
+    } else {
+        let mut files = vec![];
+        for file in args.iter().skip(1) {
+            match if file.contains("*") {
+                (|| -> io::Result<_> {
+                    for entry in glob::glob(&file).map_err(|err| {
+                        io::Error::new(io::ErrorKind::Other, err.msg)
+                    })? {
+                        files.push(entry.map_err(|_| {
+                            io::Error::new(io::ErrorKind::Other, "glob error")
+                        })?)
+                    }
+                    Ok(())
+                })()
+            } else {
+                files.push(path::PathBuf::from(file));
+                Ok(())
+            } {
+                Ok(_) => (),
+                Err(err) => {
+                    println!("{}: {}", file, err);
+                    break
+                }
+            }
+
+        }
+        // "tests/pngsuite/pngsuite.png"
+        match main_loop(files) {
+            Ok(_) => (),
+            Err(err) => println!("Error: {}", err)
+        }
+    }
+}
diff --git a/third_party/rust/png/fuzzit.sh b/third_party/rust/png/fuzzit.sh
new file mode 100755
index 0000000000..465730ffb7
--- /dev/null
+++ b/third_party/rust/png/fuzzit.sh
@@ -0,0 +1,16 @@
+# Arguments: fuzz target-id, fuzzer name
+fuzzer_target="$1"
+fuzzer_binary="$2"
+
+ORG_NAME="image-rs"
+FUZZIT_VERSION=2.4.46
+
+# Get cargo-fuzz
+cargo install cargo-fuzz
+# Build the fuzzer binary
+cargo fuzz run "$fuzzer_binary" -- -runs=0
+
+wget -O fuzzit "https://github.com/fuzzitdev/fuzzit/releases/download/v$FUZZIT_VERSION/fuzzit_Linux_x86_64"
+chmod a+x fuzzit
+./fuzzit --version
+./fuzzit create job --type local-regression "$ORG_NAME/$fuzzer_target" "./fuzz/target/x86_64-unknown-linux-gnu/debug/$fuzzer_binary"
diff --git a/third_party/rust/png/src/chunk.rs b/third_party/rust/png/src/chunk.rs
new file mode 100644
index 0000000000..9e24e6e9a0
--- /dev/null
+++ b/third_party/rust/png/src/chunk.rs
@@ -0,0 +1,59 @@
+//! Chunk types and functions
+#![allow(dead_code)]
+#![allow(non_upper_case_globals)]
+
+pub type ChunkType = [u8; 4];
+
+// -- Critical chunks --
+
+/// Image header
+pub const IHDR: ChunkType = [b'I', b'H', b'D', b'R'];
+/// Palette
+pub const PLTE: ChunkType = [b'P', b'L', b'T', b'E'];
+/// Image data
+pub const IDAT: ChunkType = [b'I', b'D', b'A', b'T'];
+/// Image trailer
+pub const IEND: ChunkType = [b'I', b'E', b'N', b'D'];
+
+// -- Ancillary chunks --
+
+/// Transparency
+pub const tRNS: ChunkType = [b't', b'R', b'N', b'S'];
+/// Background colour
+pub const bKGD: ChunkType = [b'b', b'K', b'G', b'D'];
+/// Image last-modification time
+pub const tIME: ChunkType = [b't', b'I', b'M', b'E'];
+/// Physical pixel dimensions
+pub const pHYs: ChunkType = [b'p', b'H', b'Y', b's'];
+
+// -- Extension chunks --
+
+/// Animation control
+pub const acTL: ChunkType = [b'a', b'c', b'T', b'L'];
+/// Frame control
+pub const fcTL: ChunkType = [b'f', b'c', b'T', b'L'];
+/// Frame data
+pub const fdAT: ChunkType = [b'f', b'd', b'A', b'T'];
+
+// -- Chunk type determination --
+
+/// Returns true if the chunk is critical.
+pub fn is_critical(type_: ChunkType) -> bool {
+    type_[0] & 32 == 0
+}
+
+/// Returns true if the chunk is private.
+pub fn is_private(type_: ChunkType) -> bool {
+    type_[1] & 32 != 0
+}
+
+/// Checks whether the reserved bit of the chunk name is set.
+/// If it is set the chunk name is invalid.
+pub fn reserved_set(type_: ChunkType) -> bool {
+    type_[2] & 32 != 0
+}
+
+/// Returns true if the chunk is safe to copy if unknown.
+pub fn safe_to_copy(type_: ChunkType) -> bool {
+    type_[3] & 32 != 0
+}
\ No newline at end of file
diff --git a/third_party/rust/png/src/common.rs b/third_party/rust/png/src/common.rs
new file mode 100644
index 0000000000..014efb751e
--- /dev/null
+++ b/third_party/rust/png/src/common.rs
@@ -0,0 +1,404 @@
+//! Common types shared between the encoder and decoder
+use crate::filter;
+
+use std::fmt;
+
+/// Describes the layout of samples in a pixel
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(u8)]
+pub enum ColorType {
+    Grayscale = 0,
+    RGB = 2,
+    Indexed = 3,
+    GrayscaleAlpha = 4,
+    RGBA = 6
+}
+
+impl ColorType {
+    /// Returns the number of samples used per pixel of `ColorType`
+    pub fn samples(&self) -> usize {
+        use self::ColorType::*;
+        match *self {
+            Grayscale | Indexed => 1,
+            RGB => 3,
+            GrayscaleAlpha => 2,
+            RGBA => 4
+        }
+    }
+    
+    /// u8 -> Self. Temporary solution until Rust provides a canonical one.
+    pub fn from_u8(n: u8) -> Option<ColorType> {
+        match n {
+            0 => Some(ColorType::Grayscale),
+            2 => Some(ColorType::RGB),
+            3 => Some(ColorType::Indexed),
+            4 => Some(ColorType::GrayscaleAlpha),
+            6 => Some(ColorType::RGBA),
+            _ => None
+        }
+    }
+}
+
+/// Bit depth of the png file
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(u8)]
+pub enum BitDepth {
+    One     = 1,
+    Two     = 2,
+    Four    = 4,
+    Eight   = 8,
+    Sixteen = 16,
+}
+
+impl BitDepth {
+    /// u8 -> Self. Temporary solution until Rust provides a canonical one.
+    pub fn from_u8(n: u8) -> Option<BitDepth> {
+        match n {
+            1 => Some(BitDepth::One),
+            2 => Some(BitDepth::Two),
+            4 => Some(BitDepth::Four),
+            8 => Some(BitDepth::Eight),
+            16 => Some(BitDepth::Sixteen),
+            _ => None
+        }
+    }
+}
+
+/// Pixel dimensions information
+#[derive(Clone, Copy, Debug)]
+pub struct PixelDimensions {
+    /// Pixels per unit, X axis
+    pub xppu: u32,
+    /// Pixels per unit, Y axis
+    pub yppu: u32,
+    /// Either *Meter* or *Unspecified*
+    pub unit: Unit,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(u8)]
+/// Physical unit of the pixel dimensions
+pub enum Unit {
+    Unspecified = 0,
+    Meter = 1,
+}
+
+impl Unit {
+    /// u8 -> Self. Temporary solution until Rust provides a canonical one.
+    pub fn from_u8(n: u8) -> Option<Unit> {
+        match n {
+            0 => Some(Unit::Unspecified),
+            1 => Some(Unit::Meter),
+            _ => None
+        }
+    }
+}
+
+/// How to reset buffer of an animated png (APNG) at the end of a frame.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(u8)]
+pub enum DisposeOp {
+    /// Leave the buffer unchanged.
+    None       = 0,
+    /// Clear buffer with the background color.
+    Background = 1,
+    /// Reset the buffer to the state before the current frame.
+    Previous   = 2,
+}
+
+impl DisposeOp {
+    /// u8 -> Self. Using enum_primitive or transmute is probably the right thing but this will do for now.
+    pub fn from_u8(n: u8) -> Option<DisposeOp> {
+        match n {
+            0 => Some(DisposeOp::None),
+            1 => Some(DisposeOp::Background),
+            2 => Some(DisposeOp::Previous),
+            _ => None
+        }
+    }
+}
+
+impl fmt::Display for DisposeOp {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let name = match *self {
+            DisposeOp::None => "DISPOSE_OP_NONE",
+            DisposeOp::Background => "DISPOSE_OP_BACKGROUND",
+            DisposeOp::Previous => "DISPOSE_OP_PREVIOUS",
+        };
+        write!(f, "{}", name)
+    }
+}
+
+/// How pixels are written into the buffer.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(u8)]
+pub enum BlendOp {
+    /// Pixels overwrite the value at their position.
+    Source = 0,
+    /// The new pixels are blended into the current state based on alpha.
+    Over   = 1,
+}
+
+impl BlendOp {
+    /// u8 -> Self. Using enum_primitive or transmute is probably the right thing but this will do for now.
+    pub fn from_u8(n: u8) -> Option<BlendOp> {
+        match n {
+            0 => Some(BlendOp::Source),
+            1 => Some(BlendOp::Over),
+            _ => None
+        }
+    }
+}
+
+impl fmt::Display for BlendOp {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let name = match *self {
+            BlendOp::Source => "BLEND_OP_SOURCE",
+            BlendOp::Over => "BLEND_OP_OVER",
+        };
+        write!(f, "{}", name)
+    }
+}
+
+/// Frame control information
+#[derive(Clone, Copy, Debug)]
+pub struct FrameControl {
+    /// Sequence number of the animation chunk, starting from 0
+    pub sequence_number: u32,
+    /// Width of the following frame
+    pub width: u32,
+    /// Height of the following frame
+    pub height: u32,
+    /// X position at which to render the following frame
+    pub x_offset: u32,
+    /// Y position at which to render the following frame
+    pub y_offset: u32,
+    /// Frame delay fraction numerator
+    pub delay_num: u16,
+    /// Frame delay fraction denominator
+    pub delay_den: u16,
+    /// Type of frame area disposal to be done after rendering this frame
+    pub dispose_op: DisposeOp,
+    /// Type of frame area rendering for this frame
+    pub blend_op: BlendOp,
+}
+
+impl Default for FrameControl {
+    fn default() -> FrameControl {
+        FrameControl {
+            sequence_number: 0,
+            width: 0,
+            height: 0,
+            x_offset: 0,
+            y_offset: 0,
+            delay_num: 1,
+            delay_den: 30,
+            dispose_op: DisposeOp::None,
+            blend_op: BlendOp::Source,
+        }
+    }
+}
+
+impl FrameControl {
+    pub fn set_seq_num(&mut self, s: u32) {
+        self.sequence_number = s;
+    }
+
+    pub fn inc_seq_num(&mut self, i: u32) {
+        self.sequence_number += i;
+    }
+
+}
+
+/// Animation control information
+#[derive(Clone, Copy, Debug)]
+pub struct AnimationControl {
+    /// Number of frames
+    pub num_frames: u32,
+    /// Number of times to loop this APNG.  0 indicates infinite looping.
+    pub num_plays: u32,
+}
+
+/// The type and strength of applied compression.
+#[derive(Debug, Clone)]
+pub enum Compression {
+    /// Default level  
+    Default,
+    /// Fast minimal compression
+    Fast,
+    /// Higher compression level  
+    ///
+    /// Best in this context isn't actually the highest possible level
+    /// the encoder can do, but is meant to emulate the `Best` setting in the `Flate2`
+    /// library.
+    Best,
+    Huffman,
+    Rle,
+}
+
+/// PNG info struct
+#[derive(Debug)]
+pub struct Info {
+    pub width: u32,
+    pub height: u32,
+    pub bit_depth: BitDepth,
+    pub color_type: ColorType,
+    pub interlaced: bool,
+    pub trns: Option<Vec<u8>>,
+    pub pixel_dims: Option<PixelDimensions>,
+    pub palette: Option<Vec<u8>>,
+    pub frame_control: Option<FrameControl>,
+    pub animation_control: Option<AnimationControl>,
+    pub compression: Compression,
+    pub filter: filter::FilterType,
+}
+
+impl Default for Info {
+    fn default() -> Info {
+        Info {
+            width: 0,
+            height: 0,
+            bit_depth: BitDepth::Eight,
+            color_type: ColorType::Grayscale,
+            interlaced: false,
+            palette: None,
+            trns: None,
+            pixel_dims: None,
+            frame_control: None,
+            animation_control: None,
+            // Default to `deflate::Compresion::Fast` and `filter::FilterType::Sub` 
+            // to maintain backward compatible output. 
+            compression: Compression::Fast,
+            filter: filter::FilterType::Sub,
+        }
+    }
+}
+
+impl Info {
+    /// Size of the image
+    pub fn size(&self) -> (u32, u32) {
+        (self.width, self.height)
+    }
+    
+    /// Returns true if the image is an APNG image.
+    pub fn is_animated(&self) -> bool {
+        self.frame_control.is_some() && self.animation_control.is_some()
+    }
+    
+    /// Returns the frame control information of the image
+    pub fn animation_control(&self) -> Option<&AnimationControl> {
+        self.animation_control.as_ref()
+    }
+    
+    /// Returns the frame control information of the current frame
+    pub fn frame_control(&self) -> Option<&FrameControl> {
+        self.frame_control.as_ref()
+    }
+    
+    /// Returns the bits per pixel
+    pub fn bits_per_pixel(&self) -> usize {
+        self.color_type.samples() * self.bit_depth as usize
+    }
+    
+    /// Returns the bytes per pixel
+    pub fn bytes_per_pixel(&self) -> usize {
+        self.color_type.samples() * ((self.bit_depth as usize + 7) >> 3)
+    }
+    
+    /// Returns the number of bytes needed for one deinterlaced image
+    pub fn raw_bytes(&self) -> usize {
+        self.height as usize * self.raw_row_length()
+    }
+    
+    /// Returns the number of bytes needed for one deinterlaced row 
+    pub fn raw_row_length(&self) -> usize {
+        let bits = self.width as usize * self.color_type.samples() * self.bit_depth as usize;
+        let extra = bits % 8;
+        bits/8
+        + match extra { 0 => 0, _ => 1 }
+        + 1 // filter method
+    }
+    
+    /// Returns the number of bytes needed for one deinterlaced row of width `width`
+    pub fn raw_row_length_from_width(&self, width: u32) -> usize {
+        let bits = width as usize * self.color_type.samples() * self.bit_depth as usize;
+        let extra = bits % 8;
+        bits/8
+        + match extra { 0 => 0, _ => 1 }
+        + 1 // filter method
+    }
+}
+
+
+bitflags! {
+    /// # Output transformations
+    ///
+    /// Only `IDENTITY` and `TRANSFORM_EXPAND | TRANSFORM_STRIP_ALPHA` can be used at the moment.
+    pub struct Transformations: u32 {
+        /// No transformation
+        const IDENTITY            = 0x0000; // read and write */
+        /// Strip 16-bit samples to 8 bits
+        const STRIP_16            = 0x0001; // read only */
+        /// Discard the alpha channel
+        const STRIP_ALPHA         = 0x0002; // read only */
+        /// Expand 1; 2 and 4-bit samples to bytes
+        const PACKING             = 0x0004; // read and write */
+        /// Change order of packed pixels to LSB first
+        const PACKSWAP            = 0x0008; // read and write */
+        /// Expand paletted images to RGB; expand grayscale images of
+        /// less than 8-bit depth to 8-bit depth; and expand tRNS chunks
+        /// to alpha channels.
+        const EXPAND              = 0x0010; // read only */
+        /// Invert monochrome images
+        const INVERT_MONO         = 0x0020; // read and write */
+        /// Normalize pixels to the sBIT depth
+        const SHIFT               = 0x0040; // read and write */
+        /// Flip RGB to BGR; RGBA to BGRA
+        const BGR                 = 0x0080; // read and write */
+        /// Flip RGBA to ARGB or GA to AG
+        const SWAP_ALPHA          = 0x0100; // read and write */
+        /// Byte-swap 16-bit samples
+        const SWAP_ENDIAN         = 0x0200; // read and write */
+        /// Change alpha from opacity to transparency
+        const INVERT_ALPHA        = 0x0400; // read and write */
+        const STRIP_FILLER        = 0x0800; // write only */
+        const STRIP_FILLER_BEFORE = 0x0800; // write only
+        const STRIP_FILLER_AFTER  = 0x1000; // write only */
+        const GRAY_TO_RGB         = 0x2000; // read only */
+        const EXPAND_16           = 0x4000; // read only */
+        const SCALE_16            = 0x8000; // read only */
+    }
+}
+
+/// Mod to encapsulate the converters depending on the `deflate` crate.
+///
+/// Since this only contains trait impls, there is no need to make this public, they are simply
+/// available when the mod is compiled as well.
+#[cfg(feature = "png-encoding")]
+mod deflate_convert {
+    extern crate deflate;
+    use super::Compression;
+
+    impl From<deflate::Compression> for Compression {
+        fn from(c: deflate::Compression) -> Self {
+            match c {
+                deflate::Compression::Default => Compression::Default,
+                deflate::Compression::Fast => Compression::Fast,
+                deflate::Compression::Best => Compression::Best,
+            }
+        }
+    }
+
+    impl From<Compression> for deflate::CompressionOptions {
+        fn from(c: Compression) -> Self {
+            match c {
+                Compression::Default => deflate::CompressionOptions::default(),
+                Compression::Fast => deflate::CompressionOptions::fast(),
+                Compression::Best => deflate::CompressionOptions::high(),
+                Compression::Huffman => deflate::CompressionOptions::huffman_only(),
+                Compression::Rle => deflate::CompressionOptions::rle(),
+            }
+        }
+    }
+}
+
diff --git a/third_party/rust/png/src/decoder/mod.rs b/third_party/rust/png/src/decoder/mod.rs
new file mode 100644
index 0000000000..7665983206
--- /dev/null
+++ b/third_party/rust/png/src/decoder/mod.rs
@@ -0,0 +1,543 @@
+mod stream;
+
+pub use self::stream::{StreamingDecoder, Decoded, DecodingError};
+use self::stream::{CHUNCK_BUFFER_SIZE, get_info};
+
+use std::mem;
+use std::borrow;
+use std::io::{Read, Write, BufReader, BufRead};
+
+use crate::common::{ColorType, BitDepth, Info, Transformations};
+use crate::filter::{unfilter, FilterType};
+use crate::chunk::IDAT;
+use crate::utils;
+
+/*
+pub enum InterlaceHandling {
+    /// Outputs the raw rows
+    RawRows,
+    /// Fill missing the pixels from the existing ones
+    Rectangle,
+    /// Only fill the needed pixels
+    Sparkle
+}
+*/
+
+/// Output info
+#[derive(Debug)]
+pub struct OutputInfo {
+    pub width: u32,
+    pub height: u32,
+    pub color_type: ColorType,
+    pub bit_depth: BitDepth,
+    pub line_size: usize,
+}
+
+impl OutputInfo {
+    /// Returns the size needed to hold a decoded frame
+    pub fn buffer_size(&self) -> usize {
+        self.line_size * self.height as usize
+    }
+}
+
+#[derive(Clone, Copy, Debug)]
+/// Limits on the resources the `Decoder` is allowed too use
+pub struct Limits {
+    /// maximum number of bytes the decoder is allowed to allocate, default is 64Mib
+    pub bytes: usize,
+}
+
+impl Default for Limits {
+    fn default() -> Limits {
+        Limits {
+            bytes: 1024*1024*64,
+        }
+    }
+}
+
+/// PNG Decoder
+pub struct Decoder<R: Read> {
+    /// Reader
+    r: R,
+    /// Output transformations
+    transform: Transformations,
+    /// Limits on resources the Decoder is allowed to use
+    limits: Limits,
+}
+
+impl<R: Read> Decoder<R> {
+    pub fn new(r: R) -> Decoder<R> {
+        Decoder::new_with_limits(r, Limits::default())
+    }
+    
+    pub fn new_with_limits(r: R, limits: Limits) -> Decoder<R> {
+        Decoder {
+            r,
+            transform: crate::Transformations::EXPAND | crate::Transformations::SCALE_16 | crate::Transformations::STRIP_16,
+            limits,
+        }
+    }
+
+    /// Limit resource usage
+    ///
+    /// ```
+    /// use std::fs::File;
+    /// use png::{Decoder, Limits};
+    /// // This image is 32x32 pixels, so the deocder will allocate more than four bytes
+    /// let mut limits = Limits::default();
+    /// limits.bytes = 4;
+    /// let mut decoder = Decoder::new_with_limits(File::open("tests/pngsuite/basi0g01.png").unwrap(), limits);
+    /// assert!(decoder.read_info().is_err());
+    /// // This image is 32x32 pixels, so the decoder will allocate less than 10Kib
+    /// let mut limits = Limits::default();
+    /// limits.bytes = 10*1024;
+    /// let mut decoder = Decoder::new_with_limits(File::open("tests/pngsuite/basi0g01.png").unwrap(), limits);
+    /// assert!(decoder.read_info().is_ok());
+    /// ```
+    pub fn set_limits(&mut self, limits: Limits) {
+        self.limits = limits;
+    }
+
+    /// Reads all meta data until the first IDAT chunk
+    pub fn read_info(self) -> Result<(OutputInfo, Reader<R>), DecodingError> {
+        let mut r = Reader::new(self.r, StreamingDecoder::new(), self.transform, self.limits);
+        r.init()?;
+        let (ct, bits) = r.output_color_type();
+        let info = {
+            let info = r.info();
+            OutputInfo {
+                width: info.width,
+                height: info.height,
+                color_type: ct,
+                bit_depth: bits,
+                line_size: r.output_line_size(info.width),
+            }
+        };
+        Ok((info, r))
+    }
+
+    /// Set the allowed and performed transformations.
+    ///
+    /// A transformation is a pre-processing on the raw image data modifying content or encoding.
+    /// Many options have an impact on memory or CPU usage during decoding.
+    pub fn set_transformations(&mut self, transform: Transformations) {
+        self.transform = transform;
+    }
+}
+
+struct ReadDecoder<R: Read> {
+    reader: BufReader<R>,
+    decoder: StreamingDecoder,
+    at_eof: bool
+}
+
+impl<R: Read> ReadDecoder<R> {
+    /// Returns the next decoded chunk. If the chunk is an ImageData chunk, its contents are written
+    /// into image_data.
+    fn decode_next(&mut self, image_data: &mut Vec<u8>) -> Result<Option<Decoded>, DecodingError> {
+        while !self.at_eof {
+            let (consumed, result) = {
+                let buf = self.reader.fill_buf()?;
+                if buf.is_empty() {
+                    return Err(DecodingError::Format(
+                        "unexpected EOF".into()
+                    ))
+                }
+                self.decoder.update(buf, image_data)?
+            };
+            self.reader.consume(consumed);
+            match result {
+                Decoded::Nothing => (),
+                Decoded::ImageEnd => self.at_eof = true,
+                result => return Ok(Some(result))
+            }
+        }
+        Ok(None)
+    }
+
+    fn info(&self) -> Option<&Info> {
+        get_info(&self.decoder)
+    }
+}
+
+/// PNG reader (mostly high-level interface)
+///
+/// Provides a high level that iterates over lines or whole images.
+pub struct Reader<R: Read> {
+    decoder: ReadDecoder<R>,
+    bpp: usize,
+    rowlen: usize,
+    adam7: Option<utils::Adam7Iterator>,
+    /// Previous raw line
+    prev: Vec<u8>,
+    /// Current raw line
+    current: Vec<u8>,
+    /// Output transformations
+    transform: Transformations,
+    /// Processed line
+    processed: Vec<u8>,
+    limits: Limits,
+}
+
+macro_rules! get_info(
+    ($this:expr) => {
+        $this.decoder.info().unwrap()
+    }
+);
+
+impl<R: Read> Reader<R> {
+    /// Creates a new PNG reader
+    fn new(r: R, d: StreamingDecoder, t: Transformations, limits: Limits) -> Reader<R> {
+        Reader {
+            decoder: ReadDecoder {
+                reader: BufReader::with_capacity(CHUNCK_BUFFER_SIZE, r),
+                decoder: d,
+                at_eof: false
+            },
+            bpp: 0,
+            rowlen: 0,
+            adam7: None,
+            prev: Vec::new(),
+            current: Vec::new(),
+            transform: t,
+            processed: Vec::new(),
+            limits,
+        }
+    }
+
+    /// Reads all meta data until the first IDAT chunk
+    fn init(&mut self) -> Result<(), DecodingError> {
+        use crate::Decoded::*;
+        if self.decoder.info().is_some() {
+            Ok(())
+        } else {
+            loop {
+                match self.decoder.decode_next(&mut Vec::new())? {
+                    Some(ChunkBegin(_, IDAT)) => break,
+                    None => return Err(DecodingError::Format(
+                        "IDAT chunk missing".into()
+                    )),
+                    _ => (),
+                }
+            }
+            {
+                let info = match self.decoder.info() {
+                    Some(info) => info,
+                    None => return Err(DecodingError::Format(
+                      "IHDR chunk missing".into()
+                    ))
+                };
+                self.bpp = info.bytes_per_pixel();
+                self.rowlen = info.raw_row_length();
+                if info.interlaced {
+                    self.adam7 = Some(utils::Adam7Iterator::new(info.width, info.height))
+                }
+            }
+            self.allocate_out_buf()?;
+            self.prev = vec![0; self.rowlen];
+            Ok(())
+        }
+    }
+
+    pub fn info(&self) -> &Info {
+        get_info!(self)
+    }
+
+    /// Decodes the next frame into `buf`
+    pub fn next_frame(&mut self, buf: &mut [u8]) -> Result<(), DecodingError> {
+        // TODO 16 bit
+        let (color_type, bit_depth) = self.output_color_type();
+        let width = get_info!(self).width;
+        if buf.len() < self.output_buffer_size() {
+            return Err(DecodingError::Other(
+                "supplied buffer is too small to hold the image".into()
+            ))
+        }
+        if get_info!(self).interlaced {
+             while let Some((row, adam7)) = self.next_interlaced_row()? {
+                 let (pass, line, _) = adam7.unwrap();
+                 let samples = color_type.samples() as u8;
+                 utils::expand_pass(buf, width, row, pass, line, samples * (bit_depth as u8));
+             }
+        } else {
+            let mut len = 0;
+            while let Some(row) = self.next_row()? {
+                len += (&mut buf[len..]).write(row)?;
+            }
+        }
+        Ok(())
+    }
+
+    /// Returns the next processed row of the image
+    pub fn next_row(&mut self) -> Result<Option<&[u8]>, DecodingError> {
+        self.next_interlaced_row().map(|v| v.map(|v| v.0))
+    }
+
+    /// Returns the next processed row of the image
+    pub fn next_interlaced_row(&mut self) -> Result<Option<(&[u8], Option<(u8, u32, u32)>)>, DecodingError> {
+        use crate::common::ColorType::*;
+        let transform = self.transform;
+        if transform == crate::Transformations::IDENTITY {
+            self.next_raw_interlaced_row()
+        } else {
+            // swap buffer to circumvent borrow issues
+            let mut buffer = mem::replace(&mut self.processed, Vec::new());
+            let (got_next, adam7) = if let Some((row, adam7)) = self.next_raw_interlaced_row()? {
+                (&mut buffer[..]).write_all(row)?;
+                (true, adam7)
+            } else {
+                (false, None)
+            };
+            // swap back
+            let _ = mem::replace(&mut self.processed, buffer);
+            if got_next {
+                let (color_type, bit_depth, trns) = {
+                    let info = get_info!(self);
+                    (info.color_type, info.bit_depth as u8, info.trns.is_some())
+                };
+                let output_buffer = if let Some((_, _, width)) = adam7 {
+                    let width = self.line_size(width);
+                    &mut self.processed[..width]
+                } else {
+                    &mut *self.processed
+                };
+                let mut len = output_buffer.len();
+                if transform.contains(crate::Transformations::EXPAND) {
+                    match color_type {
+                        Indexed => {
+                            expand_paletted(output_buffer, get_info!(self))?
+                        }
+                        Grayscale | GrayscaleAlpha if bit_depth < 8 => expand_gray_u8(
+                            output_buffer, get_info!(self)
+                        ),
+                        Grayscale | RGB if trns => {
+                            let channels = color_type.samples();
+                            let trns = get_info!(self).trns.as_ref().unwrap();
+                            if bit_depth == 8 {
+                                utils::expand_trns_line(output_buffer, &*trns, channels);
+                            } else {
+                                utils::expand_trns_line16(output_buffer, &*trns, channels);
+                            }
+                        },
+                        _ => ()
+                    }
+                }
+                if bit_depth == 16 && transform.intersects(crate::Transformations::SCALE_16 | crate::Transformations::STRIP_16) {
+                    len /= 2;
+                    for i in 0..len {
+                        output_buffer[i] = output_buffer[2 * i];
+                    }
+                }
+                Ok(Some((
+                    &output_buffer[..len],
+                    adam7
+                )))
+            } else {
+                Ok(None)
+            }
+        }
+    }
+
+    /// Returns the color type and the number of bits per sample
+    /// of the data returned by `Reader::next_row` and Reader::frames`.
+    pub fn output_color_type(&mut self) -> (ColorType, BitDepth) {
+        use crate::common::ColorType::*;
+        let t = self.transform;
+        let info = get_info!(self);
+        if t == crate::Transformations::IDENTITY {
+            (info.color_type, info.bit_depth)
+        } else {
+            let bits = match info.bit_depth as u8 {
+                16 if t.intersects(
+                    crate::Transformations::SCALE_16 | crate::Transformations::STRIP_16
+                ) => 8,
+                n if n < 8 && t.contains(crate::Transformations::EXPAND) => 8,
+                n => n
+            };
+            let color_type = if t.contains(crate::Transformations::EXPAND) {
+                let has_trns = info.trns.is_some();
+                match info.color_type {
+                    Grayscale if has_trns => GrayscaleAlpha,
+                    RGB if has_trns => RGBA,
+                    Indexed if has_trns => RGBA,
+                    Indexed => RGB,
+                    ct => ct
+                }
+            } else {
+                info.color_type
+            };
+            (color_type, BitDepth::from_u8(bits).unwrap())
+        }
+    }
+
+    /// Returns the number of bytes required to hold a deinterlaced image frame
+    /// that is decoded using the given input transformations.
+    pub fn output_buffer_size(&self) -> usize {
+        let (width, height) = get_info!(self).size();
+        let size = self.output_line_size(width);
+        size * height as usize
+    }
+
+    /// Returns the number of bytes required to hold a deinterlaced row.
+    pub fn output_line_size(&self, width: u32) -> usize {
+        let size = self.line_size(width);
+        if get_info!(self).bit_depth as u8 == 16 && self.transform.intersects(
+            crate::Transformations::SCALE_16 | crate::Transformations::STRIP_16
+        ) {
+            size / 2
+        } else {
+            size
+        }
+    }
+
+    /// Returns the number of bytes required to decode a deinterlaced row.
+    fn line_size(&self, width: u32) -> usize {
+        use crate::common::ColorType::*;
+        let t = self.transform;
+        let info = get_info!(self);
+        let trns = info.trns.is_some();
+        // TODO 16 bit
+        let bits = match info.color_type {
+            Indexed if trns && t.contains(crate::Transformations::EXPAND) => 4 * 8,
+            Indexed if t.contains(crate::Transformations::EXPAND) => 3 * 8,
+            RGB if trns && t.contains(crate::Transformations::EXPAND) => 4 * 8,
+            Grayscale if trns && t.contains(crate::Transformations::EXPAND) => 2 * 8,
+            Grayscale if t.contains(crate::Transformations::EXPAND) => 1 * 8,
+            GrayscaleAlpha if t.contains(crate::Transformations::EXPAND) => 2 * 8,
+            // divide by 2 as it will get mutiplied by two later
+            _ if info.bit_depth as u8 == 16 => info.bits_per_pixel() / 2,
+            _ => info.bits_per_pixel()
+        }
+        * width as usize
+        * if info.bit_depth as u8 == 16 { 2 } else { 1 };
+        let len = bits / 8;
+        let extra = bits % 8;
+        len + match extra { 0 => 0, _ => 1 }
+    }
+
+    fn allocate_out_buf(&mut self) -> Result<(), DecodingError> {
+        let width = get_info!(self).width;
+        let bytes = self.limits.bytes;
+        if bytes < self.line_size(width) {
+            return Err(DecodingError::LimitsExceeded);
+        }
+        self.processed = vec![0; self.line_size(width)];
+        Ok(())
+    }
+
+    /// Returns the next raw row of the image
+    fn next_raw_interlaced_row(&mut self) -> Result<Option<(&[u8], Option<(u8, u32, u32)>)>, DecodingError> {
+        let _ = get_info!(self);
+        let bpp = self.bpp;
+        let (rowlen, passdata) = if let Some(ref mut adam7) = self.adam7 {
+            let last_pass = adam7.current_pass();
+            if let Some((pass, line, len)) = adam7.next() {
+                let rowlen = get_info!(self).raw_row_length_from_width(len);
+                if last_pass != pass {
+                    self.prev.clear();
+                    for _ in 0..rowlen {
+                        self.prev.push(0);
+                    }
+                }
+                (rowlen, Some((pass, line, len)))
+            } else {
+                return Ok(None)
+            }
+        } else {
+            (self.rowlen, None)
+        };
+        loop {
+            if self.current.len() >= rowlen {
+                if let Some(filter) = FilterType::from_u8(self.current[0]) {
+                    if let Err(message) = unfilter(filter, bpp, &self.prev[1..rowlen], &mut self.current[1..rowlen]) {
+                        return Err(DecodingError::Format(
+                            borrow::Cow::Borrowed(message)
+                        ))
+                    }
+                    self.prev[..rowlen].copy_from_slice(&self.current[..rowlen]);
+                    self.current.drain(0..rowlen);
+                    return Ok(
+                        Some((
+                            &self.prev[1..rowlen],
+                            passdata
+                        ))
+                    )
+                } else {
+                    return Err(DecodingError::Format(
+                        format!("invalid filter method ({})", self.current[0]).into()
+                    ))
+                }
+            } else {
+                let val = self.decoder.decode_next(&mut self.current)?;
+                match val {
+                    Some(Decoded::ImageData) => {}
+                    None => {
+                        if !self.current.is_empty() {
+                            return Err(DecodingError::Format(
+                              "file truncated".into()
+                            ))
+                        } else {
+                            return Ok(None)
+                        }
+                    }
+                    _ => ()
+                }
+            }
+        }
+    }
+}
+
+fn expand_paletted(buffer: &mut [u8], info: &Info) -> Result<(), DecodingError> {
+    if let Some(palette) = info.palette.as_ref() {
+        if let BitDepth::Sixteen = info.bit_depth {
+            Err(DecodingError::Format("Bit depth '16' is not valid for paletted images".into()))
+        } else {
+            let black = [0, 0, 0];
+            if let Some(ref trns) = info.trns {
+                utils::unpack_bits(buffer, 4, info.bit_depth as u8, |i, chunk| {
+                    let (rgb, a) = (
+                        palette.get(3*i as usize..3*i as usize+3).unwrap_or(&black),
+                        *trns.get(i as usize).unwrap_or(&0xFF)
+                    );
+                    chunk[0] = rgb[0];
+                    chunk[1] = rgb[1];
+                    chunk[2] = rgb[2];
+                    chunk[3] = a;
+                });
+            } else {
+                utils::unpack_bits(buffer, 3, info.bit_depth as u8, |i, chunk| {
+                    let rgb = palette.get(3*i as usize..3*i as usize+3).unwrap_or(&black);
+                    chunk[0] = rgb[0];
+                    chunk[1] = rgb[1];
+                    chunk[2] = rgb[2];
+                })
+            }
+            Ok(())
+        }
+    } else {
+        Err(DecodingError::Format("missing palette".into()))
+    }
+}
+
+fn expand_gray_u8(buffer: &mut [u8], info: &Info) {
+    let rescale = true;
+    let scaling_factor = if rescale {
+        (255)/((1u16 << info.bit_depth as u8) - 1) as u8
+    } else {
+        1
+    };
+    if let Some(ref trns) = info.trns {
+        utils::unpack_bits(buffer, 2, info.bit_depth as u8, |pixel, chunk| {
+            if pixel == trns[0] {
+                chunk[1] = 0
+            } else {
+                chunk[1] = 0xFF
+            }
+            chunk[0] = pixel * scaling_factor
+        })
+    } else {
+        utils::unpack_bits(buffer, 1, info.bit_depth as u8, |val, chunk| {
+            chunk[0] = val * scaling_factor
+        })
+    }
+}
diff --git a/third_party/rust/png/src/decoder/stream.rs b/third_party/rust/png/src/decoder/stream.rs
new file mode 100644
index 0000000000..648a0275e5
--- /dev/null
+++ b/third_party/rust/png/src/decoder/stream.rs
@@ -0,0 +1,665 @@
+extern crate crc32fast;
+extern crate inflate;
+
+use std::borrow::Cow;
+use std::default::Default;
+use std::error;
+use std::fmt;
+use std::io;
+use std::cmp::min;
+use std::convert::From;
+
+use crc32fast::Hasher as Crc32;
+
+use self::inflate::InflateStream;
+use crate::traits::ReadBytesExt;
+use crate::common::{BitDepth, BlendOp, ColorType, DisposeOp, Info, Unit, PixelDimensions, AnimationControl, FrameControl};
+use crate::chunk::{self, ChunkType, IHDR, IDAT, IEND};
+
+/// TODO check if these size are reasonable
+pub const CHUNCK_BUFFER_SIZE: usize = 32*1024;
+
+/// Determines if checksum checks should be disabled globally.
+///
+/// This is used only in fuzzing. `afl` automatically adds `--cfg fuzzing` to RUSTFLAGS which can
+/// be used to detect that build.
+const CHECKSUM_DISABLED: bool = cfg!(fuzzing);
+
+fn zlib_stream() -> InflateStream {
+    if CHECKSUM_DISABLED {
+        InflateStream::from_zlib_no_checksum()
+    } else {
+        InflateStream::from_zlib()
+    }
+}
+
+#[derive(Debug)]
+enum U32Value {
+    // CHUNKS
+    Length,
+    Type(u32),
+    Crc(ChunkType)
+}
+
+#[derive(Debug)]
+enum State {
+    Signature(u8, [u8; 7]),
+    U32Byte3(U32Value, u32),
+    U32Byte2(U32Value, u32),
+    U32Byte1(U32Value, u32),
+    U32(U32Value),
+    ReadChunk(ChunkType, bool),
+    PartialChunk(ChunkType),
+    DecodeData(ChunkType, usize),
+}
+
+#[derive(Debug)]
+/// Result of the decoding process
+pub enum Decoded {
+    /// Nothing decoded yet
+    Nothing,
+    Header(u32, u32, BitDepth, ColorType, bool),
+    ChunkBegin(u32, ChunkType),
+    ChunkComplete(u32, ChunkType),
+    PixelDimensions(PixelDimensions),
+    AnimationControl(AnimationControl),
+    FrameControl(FrameControl),
+    /// Decoded raw image data.
+    ImageData,
+    PartialChunk(ChunkType),
+    ImageEnd,
+}
+
+#[derive(Debug)]
+pub enum DecodingError {
+    IoError(io::Error),
+    Format(Cow<'static, str>),
+    InvalidSignature,
+    CrcMismatch {
+        /// bytes to skip to try to recover from this error
+        recover: usize,
+        /// Stored CRC32 value
+        crc_val: u32,
+        /// Calculated CRC32 sum
+        crc_sum: u32,
+        chunk: ChunkType
+    },
+    Other(Cow<'static, str>),
+    CorruptFlateStream,
+    LimitsExceeded,
+}
+
+impl error::Error for DecodingError {
+    fn description(&self) -> &str {
+        use self::DecodingError::*;
+        match *self {
+            IoError(ref err) => err.description(),
+            Format(ref desc) | Other(ref desc) => &desc,
+            InvalidSignature => "invalid signature",
+            CrcMismatch { .. } => "CRC error",
+            CorruptFlateStream => "compressed data stream corrupted",
+            LimitsExceeded => "limits are exceeded"
+        }
+    }
+}
+
+impl fmt::Display for DecodingError {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        write!(fmt, "{}", (self as &dyn error::Error).description())
+    }
+}
+
+impl From<io::Error> for DecodingError {
+    fn from(err: io::Error) -> DecodingError {
+        DecodingError::IoError(err)
+    }
+}
+
+impl From<String> for DecodingError {
+    fn from(err: String) -> DecodingError {
+        DecodingError::Other(err.into())
+    }
+}
+
+impl From<DecodingError> for io::Error {
+    fn from(err: DecodingError) -> io::Error {
+        use std::error::Error;
+        match err {
+            DecodingError::IoError(err) => err,
+            err => io::Error::new(
+                io::ErrorKind::Other,
+                err.description()
+            )
+        }
+    }
+}
+
+/// PNG StreamingDecoder (low-level interface)
+pub struct StreamingDecoder {
+    state: Option<State>,
+    current_chunk: ChunkState,
+    inflater: InflateStream,
+    info: Option<Info>,
+    current_seq_no: Option<u32>,
+    have_idat: bool,
+}
+
+struct ChunkState {
+    /// Partial crc until now.
+    crc: Crc32,
+
+    /// Remanining bytes to be read.
+    remaining: u32,
+
+    /// Non-decoded bytes in the chunk.
+    raw_bytes: Vec<u8>,
+}
+
+impl StreamingDecoder {
+    /// Creates a new StreamingDecoder
+    ///
+    /// Allocates the internal buffers.
+    pub fn new() -> StreamingDecoder {
+        StreamingDecoder {
+            state: Some(State::Signature(0, [0; 7])),
+            current_chunk: ChunkState::default(),
+            inflater: zlib_stream(),
+            info: None,
+            current_seq_no: None,
+            have_idat: false
+        }
+    }
+
+    /// Resets the StreamingDecoder
+    pub fn reset(&mut self) {
+        self.state = Some(State::Signature(0, [0; 7]));
+        self.current_chunk.crc = Crc32::new();
+        self.current_chunk.remaining = 0;
+        self.current_chunk.raw_bytes.clear();
+        self.inflater = zlib_stream();
+        self.info = None;
+        self.current_seq_no = None;
+        self.have_idat = false;
+    }
+
+    /// Low level StreamingDecoder interface.
+    ///
+    /// Allows to stream partial data to the encoder. Returns a tuple containing the bytes that have
+    /// been consumed from the input buffer and the current decoding result. If the decoded chunk
+    /// was an image data chunk, it also appends the read data to `image_data`.
+    pub fn update(&mut self, mut buf: &[u8], image_data: &mut Vec<u8>)
+    -> Result<(usize, Decoded), DecodingError> {
+        let len = buf.len();
+        while !buf.is_empty() && self.state.is_some() {
+            match self.next_state(buf, image_data) {
+                Ok((bytes, Decoded::Nothing)) => {
+                    buf = &buf[bytes..]
+                }
+                Ok((bytes, result)) => {
+                    buf = &buf[bytes..];
+                    return Ok((len-buf.len(), result));
+                }
+                Err(err) => return Err(err)
+            }
+        }
+        Ok((len-buf.len(), Decoded::Nothing))
+    }
+
+    fn next_state<'a>(&'a mut self, buf: &[u8], image_data: &mut Vec<u8>)
+    -> Result<(usize, Decoded), DecodingError> {
+        use self::State::*;
+
+        macro_rules! goto (
+            ($n:expr, $state:expr) => ({
+                self.state = Some($state);
+                Ok(($n, Decoded::Nothing))
+            });
+            ($state:expr) => ({
+                self.state = Some($state);
+                Ok((1, Decoded::Nothing))
+            });
+            ($n:expr, $state:expr, emit $res:expr) => ({
+                self.state = Some($state);
+                Ok(($n, $res))
+            });
+            ($state:expr, emit $res:expr) => ({
+                self.state = Some($state);
+                Ok((1, $res))
+            })
+        );
+
+        let current_byte = buf[0];
+
+        // Driver should ensure that state is never None
+        let state = self.state.take().unwrap();
+        //println!("state: {:?}", state);
+
+        match state {
+            Signature(i, mut signature) if i < 7 => {
+                signature[i as usize] = current_byte;
+                goto!(Signature(i+1, signature))
+            }
+            Signature(_, signature) if signature == [137, 80, 78, 71, 13, 10, 26] && current_byte == 10 => {
+                goto!(U32(U32Value::Length))
+            }
+            Signature(..) => Err(DecodingError::InvalidSignature),
+            U32Byte3(type_, mut val) => {
+                use self::U32Value::*;
+                val |= u32::from(current_byte);
+                match type_ {
+                    Length => goto!(U32(Type(val))),
+                    Type(length) => {
+                        let type_str = [
+                            (val >> 24) as u8,
+                            (val >> 16) as u8,
+                            (val >> 8) as u8,
+                            val as u8
+                        ];
+                        self.current_chunk.crc.reset();
+                        self.current_chunk.crc.update(&type_str);
+                        self.current_chunk.remaining = length;
+                        goto!(
+                            ReadChunk(type_str, true),
+                            emit Decoded::ChunkBegin(length, type_str)
+                        )
+                    },
+                    Crc(type_str) => {
+                        let sum = self.current_chunk.crc.clone().finalize();
+                        if CHECKSUM_DISABLED || val == sum {
+                            goto!(
+                                State::U32(U32Value::Length),
+                                emit if type_str == IEND {
+                                    Decoded::ImageEnd
+                                } else {
+                                    Decoded::ChunkComplete(val, type_str)
+                                }
+                            )
+                        } else {
+                            Err(DecodingError::CrcMismatch {
+                                recover: 1,
+                                crc_val: val,
+                                crc_sum: sum,
+                                chunk: type_str
+                            })
+                        }
+                    },
+                }
+            },
+            U32Byte2(type_, val) => {
+                goto!(U32Byte3(type_, val | u32::from(current_byte) << 8))
+            },
+            U32Byte1(type_, val) => {
+                goto!(U32Byte2(type_, val | u32::from(current_byte) << 16))
+            },
+            U32(type_) => {
+                goto!(U32Byte1(type_,       u32::from(current_byte) << 24))
+            },
+            PartialChunk(type_str) => {
+                match type_str {
+                    IDAT => {
+                        self.have_idat = true;
+                        goto!(
+                            0,
+                            DecodeData(type_str, 0),
+                            emit Decoded::PartialChunk(type_str)
+                        )
+                    },
+                    chunk::fdAT => {
+                        if let Some(seq_no) = self.current_seq_no {
+                            let mut buf = &self.current_chunk.raw_bytes[..];
+                            let next_seq_no = buf.read_be()?;
+                            if next_seq_no != seq_no + 1 {
+                                return Err(DecodingError::Format(format!(
+                                    "Sequence is not in order, expected #{} got #{}.",
+                                    seq_no + 1,
+                                    next_seq_no
+                                ).into()))
+                            }
+                            self.current_seq_no = Some(next_seq_no);
+                        } else {
+                            return Err(DecodingError::Format("fcTL chunk missing before fdAT chunk.".into()))
+                        }
+                        goto!(
+                            0,
+                            DecodeData(type_str, 4),
+                            emit Decoded::PartialChunk(type_str)
+                        )
+                    },
+                    // Handle other chunks
+                    _ => {
+                        if self.current_chunk.remaining == 0 { // complete chunk
+                            Ok((0, self.parse_chunk(type_str)?))
+                        } else {
+                            goto!(
+                                0, ReadChunk(type_str, true),
+                                emit Decoded::PartialChunk(type_str)
+                            )
+                        }
+                    }
+                }
+
+            },
+            ReadChunk(type_str, clear) => {
+                if clear {
+                    self.current_chunk.raw_bytes.clear();
+                }
+                if self.current_chunk.remaining > 0 {
+                    let ChunkState { crc, remaining, raw_bytes } = &mut self.current_chunk;
+                    let buf_avail = raw_bytes.capacity() - raw_bytes.len();
+                    let bytes_avail = min(buf.len(), buf_avail);
+                    let n = min(*remaining, bytes_avail as u32);
+                    if buf_avail == 0 {
+                        goto!(0, PartialChunk(type_str))
+                    } else {
+                        let buf = &buf[..n as usize];
+                        crc.update(buf);
+                        raw_bytes.extend_from_slice(buf);
+                        *remaining -= n;
+                        if *remaining == 0 {
+                            goto!(n as usize, PartialChunk(type_str
+                            ))
+                        } else {
+                            goto!(n as usize, ReadChunk(type_str, false))
+                        }
+
+                    }
+                } else {
+                    goto!(0, U32(U32Value::Crc(type_str)))
+                }
+            }
+            DecodeData(type_str, mut n) => {
+                let chunk_len = self.current_chunk.raw_bytes.len();
+                let chunk_data = &self.current_chunk.raw_bytes[n..];
+                let (c, data) = self.inflater.update(chunk_data)?;
+                image_data.extend_from_slice(data);
+                n += c;
+                if n == chunk_len && data.is_empty() && c == 0 {
+                    goto!(
+                        0,
+                        ReadChunk(type_str, true),
+                        emit Decoded::ImageData
+                    )
+                } else {
+                    goto!(
+                        0,
+                        DecodeData(type_str, n),
+                        emit Decoded::ImageData
+                    )
+                }
+            }
+        }
+    }
+
+    fn parse_chunk(&mut self, type_str: [u8; 4])
+    -> Result<Decoded, DecodingError> {
+        self.state = Some(State::U32(U32Value::Crc(type_str)));
+        if self.info.is_none() && type_str != IHDR {
+            return Err(DecodingError::Format(format!(
+                "{} chunk appeared before IHDR chunk", String::from_utf8_lossy(&type_str)
+            ).into()))
+        }
+        match match type_str {
+            IHDR => {
+                self.parse_ihdr()
+            }
+            chunk::PLTE => {
+                self.parse_plte()
+            }
+            chunk::tRNS => {
+                self.parse_trns()
+            }
+            chunk::pHYs => {
+                self.parse_phys()
+            }
+            chunk::acTL => {
+                self.parse_actl()
+            }
+            chunk::fcTL => {
+                self.parse_fctl()
+            }
+            _ => Ok(Decoded::PartialChunk(type_str))
+        } {
+            Err(err) =>{
+                // Borrow of self ends here, because Decoding error does not borrow self.
+                self.state = None;
+                Err(err)
+            },
+            ok => ok
+        }
+    }
+
+    fn get_info_or_err(&self) -> Result<&Info, DecodingError> {
+        self.info.as_ref().ok_or_else(|| DecodingError::Format(
+            "IHDR chunk missing".into()
+        ))
+    }
+
+    fn parse_fctl(&mut self)
+    -> Result<Decoded, DecodingError> {
+        let mut buf = &self.current_chunk.raw_bytes[..];
+        let next_seq_no = buf.read_be()?;
+
+        // Asuming that fcTL is required before *every* fdAT-sequence
+        self.current_seq_no = Some(if let Some(seq_no) = self.current_seq_no {
+            if next_seq_no != seq_no + 1 {
+                return Err(DecodingError::Format(format!(
+                    "Sequence is not in order, expected #{} got #{}.",
+                    seq_no + 1,
+                    next_seq_no
+                ).into()))
+            }
+            next_seq_no
+        } else {
+            if next_seq_no != 0 {
+                return Err(DecodingError::Format(format!(
+                    "Sequence is not in order, expected #{} got #{}.",
+                    0,
+                    next_seq_no
+                ).into()))
+            }
+            0
+        });
+        self.inflater = zlib_stream();
+        let fc = FrameControl {
+            sequence_number: next_seq_no,
+            width: buf.read_be()?,
+            height: buf.read_be()?,
+            x_offset: buf.read_be()?,
+            y_offset: buf.read_be()?,
+            delay_num: buf.read_be()?,
+            delay_den: buf.read_be()?,
+            dispose_op: match DisposeOp::from_u8(buf.read_be()?) {
+                Some(dispose_op) => dispose_op,
+                None => return Err(DecodingError::Format("invalid dispose operation".into()))
+            },
+            blend_op : match BlendOp::from_u8(buf.read_be()?) {
+                Some(blend_op) => blend_op,
+                None => return Err(DecodingError::Format("invalid blend operation".into()))
+            },
+        };
+        self.info.as_mut().unwrap().frame_control = Some(fc);
+        Ok(Decoded::FrameControl(fc))
+    }
+
+    fn parse_actl(&mut self)
+    -> Result<Decoded, DecodingError> {
+        if self.have_idat {
+            Err(DecodingError::Format(
+                "acTL chunk appeared after first IDAT chunk".into()
+            ))
+        } else {
+            let mut buf = &self.current_chunk.raw_bytes[..];
+            let actl = AnimationControl {
+                num_frames: buf.read_be()?,
+                num_plays: buf.read_be()?
+            };
+            self.info.as_mut().unwrap().animation_control = Some(actl);
+            Ok(Decoded::AnimationControl(actl))
+        }
+    }
+
+    fn parse_plte(&mut self)
+    -> Result<Decoded, DecodingError> {
+        if let Some(info) = self.info.as_mut() {
+            info.palette = Some(self.current_chunk.raw_bytes.clone())
+        }
+        Ok(Decoded::Nothing)
+    }
+
+    fn parse_trns(&mut self)
+    -> Result<Decoded, DecodingError> {
+        use crate::common::ColorType::*;
+        let (color_type, bit_depth) = {
+            let info = self.get_info_or_err()?;
+            (info.color_type, info.bit_depth as u8)
+        };
+        let vec = self.current_chunk.raw_bytes.clone();
+        let len = vec.len();
+        let info = match self.info {
+            Some(ref mut info) => info,
+            None => return Err(DecodingError::Format(
+              "tRNS chunk occured before IHDR chunk".into()
+            ))
+        };
+        info.trns = Some(vec);
+        let vec = info.trns.as_mut().unwrap();
+        match color_type {
+            Grayscale => {
+                if len < 2 {
+                    return Err(DecodingError::Format(
+                        "not enough palette entries".into()
+                    ))
+                }
+                if bit_depth < 16 {
+                    vec[0] = vec[1];
+                    vec.truncate(1);
+                }
+                Ok(Decoded::Nothing)
+            },
+            RGB => {
+                if len < 6 {
+                    return Err(DecodingError::Format(
+                        "not enough palette entries".into()
+                    ))
+                }
+                if bit_depth < 16 {
+                    vec[0] = vec[1];
+                    vec[1] = vec[3];
+                    vec[2] = vec[5];
+                    vec.truncate(3);
+                }
+                Ok(Decoded::Nothing)
+            },
+            Indexed => {
+                let _ = info.palette.as_ref().ok_or_else(|| DecodingError::Format(
+                    "tRNS chunk occured before PLTE chunk".into()
+                ));
+                Ok(Decoded::Nothing)
+            },
+            c => Err(DecodingError::Format(
+                format!("tRNS chunk found for color type ({})", c as u8).into()
+            ))
+        }
+
+    }
+
+    fn parse_phys(&mut self)
+    -> Result<Decoded, DecodingError> {
+        if self.have_idat {
+            Err(DecodingError::Format(
+                "pHYs chunk appeared after first IDAT chunk".into()
+            ))
+        } else {
+            let mut buf = &self.current_chunk.raw_bytes[..];
+            let xppu = buf.read_be()?;
+            let yppu = buf.read_be()?;
+            let unit = buf.read_be()?;
+            let unit = match Unit::from_u8(unit) {
+                Some(unit) => unit,
+                None => return Err(DecodingError::Format(
+                    format!("invalid unit ({})", unit).into()
+                ))
+            };
+            let pixel_dims = PixelDimensions {
+                xppu,
+                yppu,
+                unit,
+            };
+            self.info.as_mut().unwrap().pixel_dims = Some(pixel_dims);
+            Ok(Decoded::PixelDimensions(pixel_dims))
+        }
+    }
+
+    fn parse_ihdr(&mut self)
+    -> Result<Decoded, DecodingError> {
+        // TODO: check if color/bit depths combination is valid
+        let mut buf = &self.current_chunk.raw_bytes[..];
+        let width = buf.read_be()?;
+        let height = buf.read_be()?;
+        let bit_depth = buf.read_be()?;
+        let bit_depth = match BitDepth::from_u8(bit_depth) {
+            Some(bits) => bits,
+            None => return Err(DecodingError::Format(
+                format!("invalid bit depth ({})", bit_depth).into()
+            ))
+        };
+        let color_type = buf.read_be()?;
+        let color_type = match ColorType::from_u8(color_type) {
+            Some(color_type) => color_type,
+            None => return Err(DecodingError::Format(
+                format!("invalid color type ({})", color_type).into()
+            ))
+        };
+        match buf.read_be()? { // compression method
+            0u8 => (),
+            n => return Err(DecodingError::Format(
+                format!("unknown compression method ({})", n).into()
+            ))
+        }
+        match buf.read_be()? { // filter method
+            0u8 => (),
+            n => return Err(DecodingError::Format(
+                format!("unknown filter method ({})", n).into()
+            ))
+        }
+        let interlaced = match buf.read_be()? {
+            0u8 => false,
+            1 => {
+                true
+            },
+            n => return Err(DecodingError::Format(
+                format!("unknown interlace method ({})", n).into()
+            ))
+        };
+        let mut info = Info::default();
+
+        info.width = width;
+        info.height = height;
+        info.bit_depth = bit_depth;
+        info.color_type = color_type;
+        info.interlaced = interlaced;
+        self.info = Some(info);
+        Ok(Decoded::Header(
+            width,
+            height,
+            bit_depth,
+            color_type,
+            interlaced
+        ))
+    }
+}
+
+impl Default for ChunkState {
+    fn default() -> Self {
+        ChunkState {
+            crc:Crc32::new(),
+            remaining: 0,
+            raw_bytes: Vec::with_capacity(CHUNCK_BUFFER_SIZE),
+        }
+    }
+}
+
+#[inline(always)]
+pub fn get_info(d: &StreamingDecoder) -> Option<&Info> {
+    d.info.as_ref()
+}
diff --git a/third_party/rust/png/src/encoder.rs b/third_party/rust/png/src/encoder.rs
new file mode 100644
index 0000000000..ffa6629ec5
--- /dev/null
+++ b/third_party/rust/png/src/encoder.rs
@@ -0,0 +1,477 @@
+extern crate crc32fast;
+extern crate deflate;
+
+use std::borrow::Cow;
+use std::error;
+use std::fmt;
+use std::io::{self, Read, Write};
+use std::mem;
+use std::result;
+
+use crc32fast::Hasher as Crc32;
+
+use crate::chunk;
+use crate::common::{Info, ColorType, BitDepth, Compression};
+use crate::filter::{FilterType, filter};
+use crate::traits::WriteBytesExt;
+
+pub type Result<T> = result::Result<T, EncodingError>;
+
+#[derive(Debug)]
+pub enum EncodingError {
+    IoError(io::Error),
+    Format(Cow<'static, str>),
+}
+
+impl error::Error for EncodingError {
+    fn description(&self) -> &str {
+        use self::EncodingError::*;
+        match *self {
+            IoError(ref err) => err.description(),
+            Format(ref desc) => &desc,
+        }
+    }
+}
+
+impl fmt::Display for EncodingError {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        write!(fmt, "{}", (self as &dyn error::Error).description())
+    }
+}
+
+impl From<io::Error> for EncodingError {
+    fn from(err: io::Error) -> EncodingError {
+        EncodingError::IoError(err)
+    }
+}
+impl From<EncodingError> for io::Error {
+    fn from(err: EncodingError) -> io::Error {
+        io::Error::new(io::ErrorKind::Other, (&err as &dyn error::Error).description())
+    }
+}
+
+/// PNG Encoder
+pub struct Encoder<W: Write> {
+    w: W,
+    info: Info,
+}
+
+impl<W: Write> Encoder<W> {
+    pub fn new(w: W, width: u32, height: u32) -> Encoder<W> {
+        let mut info = Info::default();
+        info.width = width;
+        info.height = height;
+        Encoder { w, info }
+    }
+
+    pub fn write_header(self) -> Result<Writer<W>> {
+        Writer::new(self.w, self.info).init()
+    }
+
+    /// Set the color of the encoded image.
+    ///
+    /// These correspond to the color types in the png IHDR data that will be written. The length
+    /// of the image data that is later supplied must match the color type, otherwise an error will
+    /// be emitted.
+    pub fn set_color(&mut self, color: ColorType) {
+        self.info.color_type = color;
+    }
+
+    /// Set the indicated depth of the image data.
+    pub fn set_depth(&mut self, depth: BitDepth) {
+        self.info.bit_depth = depth;
+    }
+
+    /// Set compression parameters.
+    ///
+    /// Accepts a `Compression` or any type that can transform into a `Compression`. Notably `deflate::Compression` and
+    /// `deflate::CompressionOptions` which "just work".
+    pub fn set_compression<C: Into<Compression>>(&mut self, compression: C) {
+        self.info.compression = compression.into();
+    }
+
+    /// Set the used filter type.
+    ///
+    /// The default filter is [`FilterType::Sub`] which provides a basic prediction algorithm for
+    /// sample values based on the previous. For a potentially better compression ratio, at the
+    /// cost of more complex processing, try out [`FilterType::Paeth`].
+    ///
+    /// [`FilterType::Sub`]: enum.FilterType.html#variant.Sub
+    /// [`FilterType::Paeth`]: enum.FilterType.html#variant.Paeth
+    pub fn set_filter(&mut self, filter: FilterType) {
+        self.info.filter = filter;
+    }
+}
+
+/// PNG writer
+pub struct Writer<W: Write> {
+    w: W,
+    info: Info,
+}
+
+impl<W: Write> Writer<W> {
+    fn new(w: W, info: Info) -> Writer<W> {
+        Writer { w, info }
+    }
+
+    fn init(mut self) -> Result<Self> {
+        if self.info.width == 0 {
+            return Err(EncodingError::Format("Zero width not allowed".into()));
+        }
+
+        if self.info.height == 0 {
+            return Err(EncodingError::Format("Zero height not allowed".into()));
+        }
+
+        self.w.write_all(&[137, 80, 78, 71, 13, 10, 26, 10])?;
+        let mut data = [0; 13];
+        (&mut data[..]).write_be(self.info.width)?;
+        (&mut data[4..]).write_be(self.info.height)?;
+        data[8] = self.info.bit_depth as u8;
+        data[9] = self.info.color_type as u8;
+        data[12] = if self.info.interlaced { 1 } else { 0 };
+        self.write_chunk(chunk::IHDR, &data)?;
+        Ok(self)
+    }
+
+    pub fn write_chunk(&mut self, name: [u8; 4], data: &[u8]) -> Result<()> {
+        self.w.write_be(data.len() as u32)?;
+        self.w.write_all(&name)?;
+        self.w.write_all(data)?;
+        let mut crc = Crc32::new();
+        crc.update(&name);
+        crc.update(data);
+        self.w.write_be(crc.finalize())?;
+        Ok(())
+    }
+
+    /// Writes the image data.
+    pub fn write_image_data(&mut self, data: &[u8]) -> Result<()> {
+        const MAX_CHUNK_LEN: u32 = (1u32 << 31) - 1;
+        let bpp = self.info.bytes_per_pixel();
+        let in_len = self.info.raw_row_length() - 1;
+        let mut prev = vec![0; in_len];
+        let mut current = vec![0; in_len];
+        let data_size = in_len * self.info.height as usize;
+        if data_size != data.len() {
+            let message = format!("wrong data size, expected {} got {}", data_size, data.len());
+            return Err(EncodingError::Format(message.into()));
+        }
+        let mut zlib = deflate::write::ZlibEncoder::new(Vec::new(), self.info.compression.clone());
+        let filter_method = self.info.filter;
+        for line in data.chunks(in_len) {
+            current.copy_from_slice(&line);
+            zlib.write_all(&[filter_method as u8])?;
+            filter(filter_method, bpp, &prev, &mut current);
+            zlib.write_all(&current)?;
+            mem::swap(&mut prev, &mut current);
+        }
+        let zlib_encoded = zlib.finish()?;
+        for chunk in zlib_encoded.chunks(MAX_CHUNK_LEN as usize) {
+            self.write_chunk(chunk::IDAT, &chunk)?;
+        }
+        Ok(())
+    }
+
+    /// Create an stream writer.
+    ///
+    /// This allows you create images that do not fit
+    /// in memory. The default chunk size is 4K, use
+    /// `stream_writer_with_size` to set another chuck
+    /// size.
+    pub fn stream_writer(&mut self) -> StreamWriter<W> {
+        self.stream_writer_with_size(4 * 1024)
+    }
+
+    /// Create a stream writer with custom buffer size.
+    ///
+    /// See `stream_writer`
+    pub fn stream_writer_with_size(&mut self, size: usize) -> StreamWriter<W> {
+        StreamWriter::new(self, size)
+    }
+}
+
+impl<W: Write> Drop for Writer<W> {
+    fn drop(&mut self) {
+        let _ = self.write_chunk(chunk::IEND, &[]);
+    }
+}
+
+struct ChunkWriter<'a, W: Write> {
+    writer: &'a mut Writer<W>,
+    buffer: Vec<u8>,
+    index: usize,
+}
+
+impl<'a, W: Write> ChunkWriter<'a, W> {
+    fn new(writer: &'a mut Writer<W>, buf_len: usize) -> ChunkWriter<'a, W> {
+        ChunkWriter {
+            writer,
+            buffer: vec![0; buf_len],
+            index: 0,
+        }
+    }
+}
+
+impl<'a, W: Write> Write for ChunkWriter<'a, W> {
+    fn write(&mut self, mut buf: &[u8]) -> io::Result<usize> {
+        let written = buf.read(&mut self.buffer[self.index..])?;
+        self.index += written;
+        
+        if self.index + 1 >= self.buffer.len() {
+            self.writer.write_chunk(chunk::IDAT, &self.buffer)?;
+            self.index = 0;
+        }
+
+        Ok(written)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        if self.index > 0 {
+            self.writer.write_chunk(chunk::IDAT, &self.buffer[..=self.index])?;
+        }
+        self.index = 0;
+        Ok(())
+    }
+}
+
+impl<'a, W: Write> Drop for ChunkWriter<'a, W> {
+    fn drop(&mut self) {
+        let _ = self.flush();
+    }
+}
+
+
+/// Streaming png writer
+///
+/// This may silently fail in the destructor, so it is a good idea to call
+/// [`finish`](#method.finish) or [`flush`](https://doc.rust-lang.org/stable/std/io/trait.Write.html#tymethod.flush) before dropping. 
+pub struct StreamWriter<'a, W: Write> {
+    writer: deflate::write::ZlibEncoder<ChunkWriter<'a, W>>,
+    prev_buf: Vec<u8>,
+    curr_buf: Vec<u8>,
+    index: usize,
+    bpp: usize,
+    filter: FilterType,
+}
+
+impl<'a, W: Write> StreamWriter<'a, W> {
+    fn new(writer: &'a mut Writer<W>, buf_len: usize) -> StreamWriter<'a, W> {
+        let bpp      = writer.info.bytes_per_pixel();
+        let in_len   = writer.info.raw_row_length() - 1;
+        let filter   = writer.info.filter;
+        let prev_buf = vec![0; in_len];
+        let curr_buf = vec![0; in_len];
+
+        let compression = writer.info.compression.clone();
+        let chunk_writer = ChunkWriter::new(writer, buf_len);
+        let zlib = deflate::write::ZlibEncoder::new(chunk_writer, compression);
+
+        StreamWriter {
+            writer: zlib,
+            index: 0,
+            prev_buf,
+            curr_buf,
+            bpp,
+            filter,
+        }
+    }
+
+    pub fn finish(mut self) -> Result<()> {
+        // TODO: call `writer.finish` somehow?
+        self.flush()?;
+        Ok(())
+    }
+}
+
+impl<'a, W: Write> Write for StreamWriter<'a, W> {
+    fn write(&mut self, mut buf: &[u8]) -> io::Result<usize> {
+        let written = buf.read(&mut self.curr_buf[self.index..])?;
+        self.index += written;
+        
+        if self.index >= self.curr_buf.len() {
+            self.writer.write_all(&[self.filter as u8])?;
+            filter(self.filter, self.bpp, &self.prev_buf, &mut self.curr_buf);
+            self.writer.write_all(&self.curr_buf)?;
+            mem::swap(&mut self.prev_buf, &mut self.curr_buf);
+            self.index = 0;
+        }
+
+        Ok(written)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        self.writer.flush()?;
+        if self.index > 0 {
+            let message = format!("wrong data size, got {} bytes too many", self.index);
+            return Err(EncodingError::Format(message.into()).into());
+        }
+        Ok(())
+    }
+}
+
+impl<'a, W: Write> Drop for StreamWriter<'a, W> {
+    fn drop(&mut self) {
+        let _ = self.flush();
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    extern crate glob;
+
+    use rand::{thread_rng, Rng};
+    use std::{io, cmp};
+    use std::io::Write;
+    use std::fs::File;
+
+    #[test]
+    fn roundtrip() {
+        // More loops = more random testing, but also more test wait time
+        for _ in 0..10 {
+            for path in glob::glob("tests/pngsuite/*.png").unwrap().map(|r| r.unwrap()) {
+                if path.file_name().unwrap().to_str().unwrap().starts_with("x") {
+                    // x* files are expected to fail to decode
+                    continue;
+                }
+                // Decode image
+                let decoder = crate::Decoder::new(File::open(path).unwrap());
+                let (info, mut reader) = decoder.read_info().unwrap();
+                if info.line_size != 32 {
+                    // TODO encoding only works with line size 32?
+                    continue;
+                }
+                let mut buf = vec![0; info.buffer_size()];
+                reader.next_frame(&mut buf).unwrap();
+                // Encode decoded image
+                let mut out = Vec::new();
+                {
+                    let mut wrapper = RandomChunkWriter {
+                        rng: thread_rng(),
+                        w: &mut out
+                    };
+
+                    let mut encoder = Encoder::new(&mut wrapper, info.width, info.height).write_header().unwrap();
+                    encoder.write_image_data(&buf).unwrap();
+                }
+                // Decode encoded decoded image
+                let decoder = crate::Decoder::new(&*out);
+                let (info, mut reader) = decoder.read_info().unwrap();
+                let mut buf2 = vec![0; info.buffer_size()];
+                reader.next_frame(&mut buf2).unwrap();
+                // check if the encoded image is ok:
+                assert_eq!(buf, buf2);
+            }
+        }
+    }
+
+    #[test]
+    fn roundtrip_stream() {
+        // More loops = more random testing, but also more test wait time
+        for _ in 0..10 {
+            for path in glob::glob("tests/pngsuite/*.png").unwrap().map(|r| r.unwrap()) {
+                if path.file_name().unwrap().to_str().unwrap().starts_with("x") {
+                    // x* files are expected to fail to decode
+                    continue;
+                }
+                // Decode image
+                let decoder = crate::Decoder::new(File::open(path).unwrap());
+                let (info, mut reader) = decoder.read_info().unwrap();
+                if info.line_size != 32 {
+                    // TODO encoding only works with line size 32?
+                    continue;
+                }
+                let mut buf = vec![0; info.buffer_size()];
+                reader.next_frame(&mut buf).unwrap();
+                // Encode decoded image
+                let mut out = Vec::new();
+                {
+                    let mut wrapper = RandomChunkWriter {
+                        rng: thread_rng(),
+                        w: &mut out
+                    };
+
+                    let mut encoder = Encoder::new(&mut wrapper, info.width, info.height).write_header().unwrap();
+                    let mut stream_writer = encoder.stream_writer();
+
+                    let mut outer_wrapper = RandomChunkWriter {
+                        rng: thread_rng(),
+                        w: &mut stream_writer
+                    };
+                    
+                    outer_wrapper.write_all(&buf).unwrap();
+                }
+                // Decode encoded decoded image
+                let decoder = crate::Decoder::new(&*out);
+                let (info, mut reader) = decoder.read_info().unwrap();
+                let mut buf2 = vec![0; info.buffer_size()];
+                reader.next_frame(&mut buf2).unwrap();
+                // check if the encoded image is ok:
+                assert_eq!(buf, buf2);
+            }
+        }
+    }
+
+    #[test]
+    fn expect_error_on_wrong_image_len() -> Result<()> {
+        use std::io::Cursor;
+
+        let width = 10;
+        let height = 10;
+
+        let output = vec![0u8; 1024];
+        let writer = Cursor::new(output);
+        let mut encoder = Encoder::new(writer, width as u32, height as u32);
+        encoder.set_depth(BitDepth::Eight);
+        encoder.set_color(ColorType::RGB);
+        let mut png_writer = encoder.write_header()?;
+
+        let correct_image_size = width * height * 3;
+        let image = vec![0u8; correct_image_size + 1];
+        let result = png_writer.write_image_data(image.as_ref());
+        assert!(result.is_err());
+
+        Ok(())
+    }
+
+    #[test]
+    fn expect_error_on_empty_image() -> Result<()> {
+        use std::io::Cursor;
+
+        let output = vec![0u8; 1024];
+        let mut writer = Cursor::new(output);
+
+        let encoder = Encoder::new(&mut writer, 0, 0);
+        assert!(encoder.write_header().is_err());
+
+        let encoder = Encoder::new(&mut writer, 100, 0);
+        assert!(encoder.write_header().is_err());
+
+        let encoder = Encoder::new(&mut writer, 0, 100);
+        assert!(encoder.write_header().is_err());
+
+        Ok(())
+    }
+
+    /// A Writer that only writes a few bytes at a time
+    struct RandomChunkWriter<'a, R: Rng, W: Write + 'a> {
+        rng: R,
+        w: &'a mut W
+    }
+
+    impl<'a, R: Rng, W: Write + 'a> Write for RandomChunkWriter<'a, R, W> {
+        fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+            // choose a random length to write
+            let len = cmp::min(self.rng.gen_range(1, 50), buf.len());
+
+            self.w.write(&buf[0..len])
+        }
+
+        fn flush(&mut self) -> io::Result<()> {
+            self.w.flush()
+        }
+    }
+
+}
diff --git a/third_party/rust/png/src/filter.rs b/third_party/rust/png/src/filter.rs
new file mode 100644
index 0000000000..4f81d8e9f3
--- /dev/null
+++ b/third_party/rust/png/src/filter.rs
@@ -0,0 +1,158 @@
+use std;
+
+/// The byte level filter applied to scanlines to prepare them for compression.
+///
+/// Compression in general benefits from repetitive data. The filter is a content-aware method of
+/// compressing the range of occurring byte values to help the compression algorithm. Note that
+/// this does not operate on pixels but on raw bytes of a scanline.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(u8)]
+pub enum FilterType {
+    NoFilter = 0,
+    Sub = 1,
+    Up = 2,
+    Avg = 3,
+    Paeth = 4
+}
+
+ impl FilterType {  
+    /// u8 -> Self. Temporary solution until Rust provides a canonical one.
+    pub fn from_u8(n: u8) -> Option<FilterType> {
+        match n {
+            0 => Some(FilterType::NoFilter),
+            1 => Some(FilterType::Sub),
+            2 => Some(FilterType::Up),
+            3 => Some(FilterType::Avg),
+            4 => Some(FilterType::Paeth),
+            _ => None
+        }
+    }
+}
+
+fn filter_paeth(a: u8, b: u8, c: u8) -> u8 {
+    let ia = i16::from(a);
+    let ib = i16::from(b);
+    let ic = i16::from(c);
+
+    let p = ia + ib - ic;
+
+    let pa = (p - ia).abs();
+    let pb = (p - ib).abs();
+    let pc = (p - ic).abs();
+
+    if pa <= pb && pa <= pc {
+        a
+    } else if pb <= pc {
+        b
+    } else {
+        c
+    }
+}
+
+pub fn unfilter(filter: FilterType, bpp: usize, previous: &[u8], current: &mut [u8]) -> std::result::Result<(), &'static str> {
+    use self::FilterType::*;
+    assert!(bpp > 0);
+    let len = current.len();
+
+    match filter {
+        NoFilter => Ok(()),
+        Sub => {
+            for i in bpp..len {
+                current[i] = current[i].wrapping_add(
+                    current[i - bpp]
+                );
+            }
+            Ok(())
+        }
+        Up => {
+            if previous.len() < len {
+                Err("Filtering failed: not enough data in previous row")
+            } else {
+                for i in 0..len {
+                    current[i] = current[i].wrapping_add(
+                        previous[i]
+                    );
+                }
+                Ok(())
+            }
+        }
+        Avg => {
+            if previous.len() < len {
+                Err("Filtering failed:  not enough data in previous row")
+            } else if bpp > len {
+                Err("Filtering failed: bytes per pixel is greater than length of row")
+            } else {
+                for i in 0..bpp {
+                    current[i] = current[i].wrapping_add(
+                        previous[i] / 2
+                    );
+                }
+
+                for i in bpp..len {
+                    current[i] = current[i].wrapping_add(
+                        ((i16::from(current[i - bpp]) + i16::from(previous[i])) / 2) as u8
+                    );
+                }
+                Ok(())
+            }
+        }
+        Paeth => {
+            if previous.len() < len {
+                Err("Filtering failed: not enough data in previous row")
+            } else if bpp > len {
+                Err("Filtering failed: bytes per pixel is greater than length of row")
+            } else {
+                for i in 0..bpp {
+                    current[i] = current[i].wrapping_add(
+                        filter_paeth(0, previous[i], 0)
+                    );
+                }
+
+                for i in bpp..len {
+                    current[i] = current[i].wrapping_add(
+                        filter_paeth(current[i - bpp], previous[i], previous[i - bpp])
+                    );
+                }
+                Ok(())
+            }
+        }
+    }
+}
+
+pub fn filter(method: FilterType, bpp: usize, previous: &[u8], current: &mut [u8]) {
+    use self::FilterType::*;
+    assert!(bpp > 0);
+    let len  = current.len();
+
+    match method {
+        NoFilter => (),
+        Sub      => {
+            for i in (bpp..len).rev() {
+                current[i] = current[i].wrapping_sub(current[i - bpp]);
+            }
+        }
+        Up       => {
+            for i in 0..len {
+                current[i] = current[i].wrapping_sub(previous[i]);
+            }
+        }
+        Avg  => {
+            for i in (bpp..len).rev() {
+                current[i] = current[i].wrapping_sub(current[i - bpp].wrapping_add(previous[i]) / 2);
+            }
+
+            for i in 0..bpp {
+                current[i] = current[i].wrapping_sub(previous[i] / 2);
+            }
+        }
+        Paeth    => {
+            for i in (bpp..len).rev() {
+                current[i] = current[i].wrapping_sub(filter_paeth(current[i - bpp], previous[i], previous[i - bpp]));
+            }
+
+            for i in 0..bpp {
+                current[i] = current[i].wrapping_sub(filter_paeth(0, previous[i], 0));
+            }
+        }
+    }
+}
diff --git a/third_party/rust/png/src/lib.rs b/third_party/rust/png/src/lib.rs
new file mode 100644
index 0000000000..15e9ec3b15
--- /dev/null
+++ b/third_party/rust/png/src/lib.rs
@@ -0,0 +1,61 @@
+//! # PNG encoder and decoder
+//! This crate contains a PNG encoder and decoder. It supports reading of single lines or whole frames.
+//! ## The decoder
+//! The most important types for decoding purposes are [`Decoder`](struct.Decoder.html) and
+//! [`Reader`](struct.Reader.html). They both wrap a `std::io::Read`.
+//! `Decoder` serves as a builder for `Reader`. Calling `Decoder::read_info` reads from the `Read` until the
+//! image data is reached.
+//! ### Using the decoder
+//!     use std::fs::File;
+//!
+//!     // The decoder is a build for reader and can be used to set various decoding options
+//!     // via `Transformations`. The default output transformation is `Transformations::EXPAND
+//!     // | Transformations::STRIP_ALPHA`.
+//!     let decoder = png::Decoder::new(File::open("tests/pngsuite/basi0g01.png").unwrap());
+//!     let (info, mut reader) = decoder.read_info().unwrap();
+//!     // Allocate the output buffer.
+//!     let mut buf = vec![0; info.buffer_size()];
+//!     // Read the next frame. Currently this function should only called once.
+//!     // The default options
+//!     reader.next_frame(&mut buf).unwrap();
+//! ## Encoder
+//! ### Using the encoder
+//! ```no_run
+//! # #[cfg(feature = "png-encoding")] {
+//! // For reading and opening files
+//! use std::path::Path;
+//! use std::fs::File;
+//! use std::io::BufWriter;
+//!
+//! let path = Path::new(r"/path/to/image.png");
+//! let file = File::create(path).unwrap();
+//! let ref mut w = BufWriter::new(file);
+//!
+//! let mut encoder = png::Encoder::new(w, 2, 1); // Width is 2 pixels and height is 1.
+//! encoder.set_color(png::ColorType::RGBA);
+//! encoder.set_depth(png::BitDepth::Eight);
+//! let mut writer = encoder.write_header().unwrap();
+//!
+//! let data = [255, 0, 0, 255, 0, 0, 0, 255]; // An array containing a RGBA sequence. First pixel is red and second pixel is black.
+//! writer.write_image_data(&data).unwrap(); // Save
+//! # }
+//! ```
+//!
+//#![cfg_attr(test, feature(test))]
+
+#[macro_use] extern crate bitflags;
+
+pub mod chunk;
+mod decoder;
+#[cfg(feature = "png-encoding")]
+mod encoder;
+mod filter;
+mod traits;
+mod common;
+mod utils;
+
+pub use crate::common::*;
+pub use crate::decoder::{Decoder, Reader, OutputInfo, StreamingDecoder, Decoded, DecodingError, Limits};
+#[cfg(feature = "png-encoding")]
+pub use crate::encoder::{Encoder, Writer, StreamWriter, EncodingError};
+pub use crate::filter::FilterType;
diff --git a/third_party/rust/png/src/traits.rs b/third_party/rust/png/src/traits.rs
new file mode 100644
index 0000000000..fac36f3699
--- /dev/null
+++ b/third_party/rust/png/src/traits.rs
@@ -0,0 +1,72 @@
+use std::io;
+
+// Will be replaced by stdlib solution
+fn read_all<R: io::Read + ?Sized>(this: &mut R, buf: &mut [u8]) -> io::Result<()> {
+    let mut total = 0;
+    while total < buf.len() {
+        match this.read(&mut buf[total..]) {
+            Ok(0) => return Err(io::Error::new(io::ErrorKind::Other,
+                                               "failed to read the whole buffer")),
+            Ok(n) => total += n,
+            Err(ref e) if e.kind() == io::ErrorKind::Interrupted => {}
+            Err(e) => return Err(e),
+        }
+    }
+    Ok(())
+}
+
+/// Read extension to read big endian data
+pub trait ReadBytesExt<T>: io::Read {
+    /// Read `T` from a bytes stream. Most significant byte first.
+    fn read_be(&mut self) -> io::Result<T>;
+
+}
+
+/// Write extension to write big endian data
+pub trait WriteBytesExt<T>: io::Write {
+    /// Writes `T` to a bytes stream. Most significant byte first.
+    fn write_be(&mut self, _: T) -> io::Result<()>;
+
+}
+
+impl<W: io::Read + ?Sized> ReadBytesExt<u8> for W {
+	#[inline]
+	fn read_be(&mut self) -> io::Result<u8> {
+        let mut byte = [0];
+		read_all(self, &mut byte)?;
+        Ok(byte[0])
+	}
+}
+impl<W: io::Read + ?Sized> ReadBytesExt<u16> for W {
+	#[inline]
+	fn read_be(&mut self) -> io::Result<u16> {
+        let mut bytes = [0, 0];
+		read_all(self, &mut bytes)?;
+        Ok((u16::from(bytes[0])) << 8 | u16::from(bytes[1]))
+	}
+}
+
+impl<W: io::Read + ?Sized> ReadBytesExt<u32> for W {
+	#[inline]
+	fn read_be(&mut self) -> io::Result<u32> {
+        let mut bytes = [0, 0, 0, 0];
+		read_all(self, &mut bytes)?;
+        Ok(  (u32::from(bytes[0])) << 24 
+           | (u32::from(bytes[1])) << 16
+           | (u32::from(bytes[2])) << 8
+           |  u32::from(bytes[3])
+        )
+	}
+}
+
+impl<W: io::Write + ?Sized> WriteBytesExt<u32> for W {
+    #[inline]
+    fn write_be(&mut self, n: u32) -> io::Result<()> {
+        self.write_all(&[
+            (n >> 24) as u8,
+            (n >> 16) as u8,
+            (n >>  8) as u8,
+            n         as u8
+        ])
+    }
+}
diff --git a/third_party/rust/png/src/utils.rs b/third_party/rust/png/src/utils.rs
new file mode 100644
index 0000000000..1e91629dcf
--- /dev/null
+++ b/third_party/rust/png/src/utils.rs
@@ -0,0 +1,376 @@
+//! Utility functions
+use std::iter::{repeat, StepBy};
+use std::ops::Range;
+
+#[inline(always)]
+pub fn unpack_bits<F>(buf: &mut [u8], channels: usize, bit_depth: u8, func: F)
+where F: Fn(u8, &mut[u8]) {
+    // Return early if empty. This enables to subtract `channels` later without overflow.
+    if buf.len() < channels {
+        return;
+    }
+
+    let bits = buf.len()/channels*bit_depth as usize;
+    let extra_bits = bits % 8;
+    let entries = bits / 8 + match extra_bits {
+        0 => 0,
+        _ => 1
+    };
+    let skip = match extra_bits {
+        0 => 0,
+        n => (8-n) / bit_depth as usize
+    };
+    let mask = ((1u16 << bit_depth) - 1) as u8;
+    let i =
+        (0..entries)
+        .rev() // reverse iterator
+        .flat_map(|idx|
+            // this has to be reversed too
+            (0..8).step_by(bit_depth.into())
+            .zip(repeat(idx))
+        )
+        .skip(skip);
+    let j = (0..=buf.len() - channels).rev().step_by(channels);
+    for ((shift, i), j) in i.zip(j) {
+        let pixel = (buf[i] & (mask << shift)) >> shift;
+        func(pixel, &mut buf[j..(j + channels)])
+    }
+}
+
+pub fn expand_trns_line(buf: &mut[u8], trns: &[u8], channels: usize) {
+    // Return early if empty. This enables to subtract `channels` later without overflow.
+    if buf.len() < (channels+1) {
+        return;
+    }
+
+    let i = (0..=buf.len() / (channels+1) * channels - channels).rev().step_by(channels);
+    let j = (0..=buf.len() - (channels+1)).rev().step_by(channels+1);
+    for (i, j) in i.zip(j) {
+        let i_pixel = i;
+        let j_chunk = j;
+        if &buf[i_pixel..i_pixel+channels] == trns {
+            buf[j_chunk+channels] = 0
+        } else {
+            buf[j_chunk+channels] = 0xFF
+        }
+        for k in (0..channels).rev() {
+            buf[j_chunk+k] = buf[i_pixel+k];
+        }
+    }
+}
+
+pub fn expand_trns_line16(buf: &mut[u8], trns: &[u8], channels: usize) {
+    let c2 = 2 * channels;
+    // Return early if empty. This enables to subtract `channels` later without overflow.
+    if buf.len() < (c2+2) {
+        return;
+    }
+
+    let i = (0..=buf.len() / (c2+2) * c2 - c2).rev().step_by(c2);
+    let j = (0..=buf.len() - (c2+2)).rev().step_by(c2+2);
+    for (i, j) in i.zip(j) {
+        let i_pixel = i;
+        let j_chunk = j;
+        if &buf[i_pixel..i_pixel+c2] == trns {
+            buf[j_chunk+c2] = 0;
+            buf[j_chunk+c2 + 1] = 0
+        } else {
+            buf[j_chunk+c2] = 0xFF;
+            buf[j_chunk+c2 + 1] = 0xFF
+        }
+        for k in (0..c2).rev() {
+            buf[j_chunk+k] = buf[i_pixel+k];
+        }
+    }
+}
+
+
+/// This iterator iterates over the different passes of an image Adam7 encoded
+/// PNG image
+/// The pattern is:
+///     16462646
+///     77777777
+///     56565656
+///     77777777
+///     36463646
+///     77777777
+///     56565656
+///     77777777
+///
+#[derive(Clone)]
+pub struct Adam7Iterator {
+    line: u32,
+    lines: u32,
+    line_width: u32,
+    current_pass: u8,
+    width: u32,
+    height: u32,
+}
+
+impl Adam7Iterator {
+    pub fn new(width: u32, height: u32) -> Adam7Iterator {
+        let mut this = Adam7Iterator {
+            line: 0,
+            lines: 0,
+            line_width: 0,
+            current_pass: 1,
+            width,
+            height,
+        };
+        this.init_pass();
+        this
+    }
+
+    /// Calculates the bounds of the current pass
+    fn init_pass(&mut self) {
+        let w = f64::from(self.width);
+        let h = f64::from(self.height);
+        let (line_width, lines) = match self.current_pass {
+            1 => (w/8.0, h/8.0),
+            2 => ((w-4.0)/8.0, h/8.0),
+            3 => (w/4.0, (h-4.0)/8.0),
+            4 => ((w-2.0)/4.0, h/4.0),
+            5 => (w/2.0, (h-2.0)/4.0),
+            6 => ((w-1.0)/2.0, h/2.0),
+            7 => (w, (h-1.0)/2.0),
+            _ => unreachable!()
+        };
+        self.line_width = line_width.ceil() as u32;
+        self.lines = lines.ceil() as u32;
+        self.line = 0;
+    }
+    
+    /// The current pass#.
+    pub fn current_pass(&self) -> u8 {
+        self.current_pass
+    }
+}
+
+/// Iterates over the (passes, lines, widths)
+impl Iterator for Adam7Iterator {
+    type Item = (u8, u32, u32);
+    fn next(&mut self) -> Option<(u8, u32, u32)> {
+        if self.line < self.lines && self.line_width > 0 {
+            let this_line = self.line;
+            self.line += 1;
+            Some((self.current_pass, this_line, self.line_width))
+        } else if self.current_pass < 7 {
+            self.current_pass += 1;
+            self.init_pass();
+            self.next()
+        } else {
+            None
+        }
+    }
+}
+
+fn subbyte_pixels<'a>(scanline: &'a [u8], bits_pp: usize) -> impl Iterator<Item=u8> + 'a {
+    (0..scanline.len() * 8).step_by(bits_pp).map(move |bit_idx| {
+        let byte_idx = bit_idx / 8;
+
+        // sub-byte samples start in the high-order bits
+        let rem = 8 - bit_idx % 8 - bits_pp;
+
+        match bits_pp {
+            // evenly divides bytes
+            1 => (scanline[byte_idx] >> rem) & 1,
+            2 => (scanline[byte_idx] >> rem) & 3,
+            4 => (scanline[byte_idx] >> rem) & 15,
+            _ => unreachable!(),
+        }
+    })
+}
+
+/// Given pass, image width, and line number, produce an iterator of bit positions of pixels to copy
+/// from the input scanline to the image buffer.
+fn expand_adam7_bits(pass: u8, width: usize, line_no: usize, bits_pp: usize) -> StepBy<Range<usize>> {
+    let (line_mul, line_off, samp_mul, samp_off) = match pass {
+        1 => (8, 0, 8, 0),
+        2 => (8, 0, 8, 4),
+        3 => (8, 4, 4, 0),
+        4 => (4, 0, 4, 2),
+        5 => (4, 2, 2, 0),
+        6 => (2, 0, 2, 1),
+        7 => (2, 1, 1, 0),
+        _ => panic!("Adam7 pass out of range: {}", pass)
+    };
+
+    // the equivalent line number in progressive scan
+    let prog_line = line_mul * line_no + line_off;
+    // line width is rounded up to the next byte
+    let line_width = (width * bits_pp + 7) & !7;
+    let line_start = prog_line * line_width;
+    let start = line_start + (samp_off * bits_pp);
+    let stop = line_start + (width * bits_pp);
+
+    (start .. stop).step_by(bits_pp * samp_mul)
+}
+
+/// Expands an Adam 7 pass
+pub fn expand_pass(
+    img: &mut [u8], width: u32, scanline: &[u8],
+    pass: u8, line_no: u32, bits_pp: u8) {
+
+    let width = width as usize;
+    let line_no = line_no as usize;
+    let bits_pp = bits_pp as usize;
+
+	// pass is out of range but don't blow up
+    if pass == 0 || pass > 7 { return; }
+
+    let bit_indices = expand_adam7_bits(pass, width, line_no, bits_pp);
+
+    if bits_pp < 8 {
+        for (pos, px) in bit_indices.zip(subbyte_pixels(scanline, bits_pp)) {
+            let rem = 8 - pos % 8 - bits_pp;
+            img[pos / 8] |= px << rem as u8;
+        }
+    } else {
+		let bytes_pp = bits_pp / 8;
+
+		for (bitpos, px) in bit_indices.zip(scanline.chunks(bytes_pp)) {
+			for (offset, val) in px.iter().enumerate() {
+				img[bitpos / 8 + offset] = *val;
+			}
+		}
+	}
+}
+
+#[test]
+fn test_adam7() {
+    /*
+        1646
+        7777
+        5656
+        7777
+    */
+    let it = Adam7Iterator::new(4, 4);
+    let passes: Vec<_> = it.collect();
+    assert_eq!(&*passes, &[(1, 0, 1), (4, 0, 1), (5, 0, 2), (6, 0, 2), (6, 1, 2), (7, 0, 4), (7, 1, 4)]);
+}
+
+#[test]
+fn test_subbyte_pixels() {
+    let scanline = &[0b10101010, 0b10101010];
+
+
+    let pixels = subbyte_pixels(scanline, 1).collect::<Vec<_>>();
+    assert_eq!(pixels.len(), 16);
+    assert_eq!(pixels, [1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0]);
+}
+
+#[test]
+fn test_expand_adam7_bits() {
+    let width = 32;
+    let bits_pp = 1;
+
+    let expected = |offset: usize, step: usize, count: usize| (0 .. count).map(move |i| step * i + offset).collect::<Vec<_>>();
+
+    for line_no in 0..8 {
+        let start = 8 * line_no * width;
+
+        assert_eq!(
+            expand_adam7_bits(1, width, line_no, bits_pp).collect::<Vec<_>>(),
+            expected(start, 8, 4)
+        );
+
+        let start = start + 4;
+
+        assert_eq!(
+            expand_adam7_bits(2, width, line_no, bits_pp).collect::<Vec<_>>(),
+            expected(start, 8, 4)
+        );
+
+        let start = (8 * line_no + 4) as usize * width as usize;
+
+        assert_eq!(
+            expand_adam7_bits(3, width, line_no, bits_pp).collect::<Vec<_>>(),
+            expected(start, 4, 8)
+        );
+    }
+
+    for line_no in 0 .. 16 {
+        let start = 4 * line_no * width + 2;
+
+        assert_eq!(
+            expand_adam7_bits(4, width, line_no, bits_pp).collect::<Vec<_>>(),
+            expected(start, 4, 8)
+        );
+
+        let start = (4 * line_no + 2) * width;
+
+        assert_eq!(
+            expand_adam7_bits(5, width, line_no, bits_pp).collect::<Vec<_>>(),
+            expected(start, 2, 16)
+        )
+    }
+
+    for line_no in 0 .. 32 {
+        let start = 2 * line_no * width + 1;
+
+        assert_eq!(
+            expand_adam7_bits(6, width, line_no, bits_pp).collect::<Vec<_>>(),
+            expected(start, 2, 16),
+            "line_no: {}", line_no
+        );
+
+        let start = (2 * line_no + 1) * width;
+
+        assert_eq!(
+            expand_adam7_bits(7, width, line_no, bits_pp).collect::<Vec<_>>(),
+            expected(start, 1, 32)
+        );
+    }
+}
+
+#[test]
+fn test_expand_pass_subbyte() {
+    let mut img = [0u8; 8];
+    let width = 8;
+    let bits_pp = 1;
+
+    expand_pass(&mut img, width, &[0b10000000], 1, 0, bits_pp);
+    assert_eq!(img, [0b10000000u8, 0, 0, 0, 0, 0, 0, 0]);
+
+    expand_pass(&mut img, width, &[0b10000000], 2, 0, bits_pp);
+    assert_eq!(img, [0b10001000u8, 0, 0, 0, 0, 0, 0, 0]);
+
+    expand_pass(&mut img, width, &[0b11000000], 3, 0, bits_pp);
+    assert_eq!(img, [0b10001000u8, 0, 0, 0, 0b10001000, 0, 0, 0]);
+
+    expand_pass(&mut img, width, &[0b11000000], 4, 0, bits_pp);
+    assert_eq!(img, [0b10101010u8, 0, 0, 0, 0b10001000, 0, 0, 0]);
+
+    expand_pass(&mut img, width, &[0b11000000], 4, 1, bits_pp);
+    assert_eq!(img, [0b10101010u8, 0, 0, 0, 0b10101010, 0, 0, 0]);
+
+    expand_pass(&mut img, width, &[0b11110000], 5, 0, bits_pp);
+    assert_eq!(img, [0b10101010u8, 0, 0b10101010, 0, 0b10101010, 0, 0, 0]);
+
+    expand_pass(&mut img, width, &[0b11110000], 5, 1, bits_pp);
+    assert_eq!(img, [0b10101010u8, 0, 0b10101010, 0, 0b10101010, 0, 0b10101010, 0]);
+
+    expand_pass(&mut img, width, &[0b11110000], 6, 0, bits_pp);
+    assert_eq!(img, [0b11111111u8, 0, 0b10101010, 0, 0b10101010, 0, 0b10101010, 0]);
+
+    expand_pass(&mut img, width, &[0b11110000], 6, 1, bits_pp);
+    assert_eq!(img, [0b11111111u8, 0, 0b11111111, 0, 0b10101010, 0, 0b10101010, 0]);
+
+    expand_pass(&mut img, width, &[0b11110000], 6, 2, bits_pp);
+    assert_eq!(img, [0b11111111u8, 0, 0b11111111, 0, 0b11111111, 0, 0b10101010, 0]);
+
+    expand_pass(&mut img, width, &[0b11110000], 6, 3, bits_pp);
+    assert_eq!([0b11111111u8, 0, 0b11111111, 0, 0b11111111, 0, 0b11111111, 0], img);
+
+    expand_pass(&mut img, width, &[0b11111111], 7, 0, bits_pp);
+    assert_eq!([0b11111111u8, 0b11111111, 0b11111111, 0, 0b11111111, 0, 0b11111111, 0], img);
+
+    expand_pass(&mut img, width, &[0b11111111], 7, 1, bits_pp);
+    assert_eq!([0b11111111u8, 0b11111111, 0b11111111, 0b11111111, 0b11111111, 0, 0b11111111, 0], img);
+
+    expand_pass(&mut img, width, &[0b11111111], 7, 2, bits_pp);
+    assert_eq!([0b11111111u8, 0b11111111, 0b11111111, 0b11111111, 0b11111111, 0b11111111, 0b11111111, 0], img);
+
+    expand_pass(&mut img, width, &[0b11111111], 7, 3, bits_pp);
+    assert_eq!([0b11111111u8, 0b11111111, 0b11111111, 0b11111111, 0b11111111, 0b11111111, 0b11111111, 0b11111111], img);
+}