Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

7 files changed, 585 insertions, 0 deletions

diff --git a/third_party/rust/askama_escape/.cargo-checksum.json b/third_party/rust/askama_escape/.cargo-checksum.json
new file mode 100644
index 0000000000..b4c6a0e725
--- /dev/null
+++ b/third_party/rust/askama_escape/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{"Cargo.toml":"a140f9df40d83c3f3c39864df0e272bde3e210ad9d37cf90342c45f137c5b1aa","LICENSE-APACHE":"87cb0d734c723c083e51c825930ff42bce28596b52dee15567f6b28f19c195e3","LICENSE-MIT":"df20e0180764bf5bd76f74d47bc9e8c0069a666401629c390003a1d5eba99c92","README.md":"f1c057bd94aff0d98bcd7267655bb8af4c9c81a643423c5948f711e199945905","benches/all.rs":"0e0458780fa24e55402b11fdbc6ef2191b399459461a9f909a516363e824c838","src/lib.rs":"5f96ad55ac916b63ef051373994c08a0bfaa3b85a5bf031a579dc23163c47267"},"package":"619743e34b5ba4e9703bba34deac3427c72507c7159f5fd030aea8cac0cfe341"}
\ No newline at end of file
diff --git a/third_party/rust/askama_escape/Cargo.toml b/third_party/rust/askama_escape/Cargo.toml
new file mode 100644
index 0000000000..d4944ed6ea
--- /dev/null
+++ b/third_party/rust/askama_escape/Cargo.toml
@@ -0,0 +1,33 @@
+# 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 are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2018"
+name = "askama_escape"
+version = "0.10.3"
+description = "Optimized HTML escaping code, extracted from Askama"
+homepage = "https://github.com/djc/askama"
+documentation = "https://docs.rs/askama_escape"
+readme = "README.md"
+keywords = ["html", "escaping"]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/djc/askama"
+
+[[bench]]
+name = "all"
+harness = false
+[dev-dependencies.criterion]
+version = "0.3"
+
+[features]
+json = []
+[badges.maintenance]
+status = "actively-developed"
diff --git a/third_party/rust/askama_escape/LICENSE-APACHE b/third_party/rust/askama_escape/LICENSE-APACHE
new file mode 100644
index 0000000000..b7ca568694
--- /dev/null
+++ b/third_party/rust/askama_escape/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 2017-2020 Dirkjan Ochtman
+
+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/askama_escape/LICENSE-MIT b/third_party/rust/askama_escape/LICENSE-MIT
new file mode 100644
index 0000000000..c765f2e75a
--- /dev/null
+++ b/third_party/rust/askama_escape/LICENSE-MIT
@@ -0,0 +1,25 @@
+Copyright (c) 2017-2020 Dirkjan Ochtman
+
+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/askama_escape/README.md b/third_party/rust/askama_escape/README.md
new file mode 100644
index 0000000000..8c6796d83b
--- /dev/null
+++ b/third_party/rust/askama_escape/README.md
@@ -0,0 +1,9 @@
+# askama_escape: escaping utilities for the Askama templating engine
+
+[![Documentation](https://docs.rs/askama_escape/badge.svg)](https://docs.rs/askama_escape/)
+[![Latest version](https://img.shields.io/crates/v/askama_escape.svg)](https://crates.io/crates/askama_escape)
+[![Build Status](https://github.com/djc/askama/workflows/CI/badge.svg)](https://github.com/djc/askama/actions?query=workflow%3ACI)
+[![Chat](https://badges.gitter.im/gitterHQ/gitter.svg)](https://gitter.im/djc/askama)
+
+This crate contains helper code for HTML escaping used by the
+[Askama](https://github.com/djc/askama) templating engine.
diff --git a/third_party/rust/askama_escape/benches/all.rs b/third_party/rust/askama_escape/benches/all.rs
new file mode 100644
index 0000000000..e0ef11f123
--- /dev/null
+++ b/third_party/rust/askama_escape/benches/all.rs
@@ -0,0 +1,77 @@
+#[macro_use]
+extern crate criterion;
+
+use askama_escape::{Html, MarkupDisplay};
+use criterion::Criterion;
+
+criterion_main!(benches);
+criterion_group!(benches, functions);
+
+fn functions(c: &mut Criterion) {
+    c.bench_function("Escaping", escaping);
+}
+
+fn escaping(b: &mut criterion::Bencher<'_>) {
+    let string_long = r#"
+    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Mauris consequat tellus sit
+    amet ornare fermentum. Etiam nec erat ante. In at metus a orci mollis scelerisque.
+    Sed eget ultrices turpis, at sollicitudin erat. Integer hendrerit nec magna quis
+    venenatis. Vivamus non dolor hendrerit, vulputate velit sed, varius nunc. Quisque
+    in pharetra mi. Sed ullamcorper nibh malesuada commodo porttitor. Ut scelerisque
+    sodales felis quis dignissim. Morbi aliquam finibus justo, sit amet consectetur
+    mauris efficitur sit amet. Donec posuere turpis felis, eu lacinia magna accumsan
+    quis. Fusce egestas lacus vel fermentum tincidunt. Phasellus a nulla eget lectus
+    placerat commodo at eget nisl. Fusce cursus dui quis purus accumsan auctor.
+    Donec iaculis felis quis metus consectetur porttitor.
+<p>
+    Etiam nibh mi, <b>accumsan</b> quis purus sed, posuere fermentum lorem. In pulvinar porta
+    maximus. Fusce tincidunt lacinia tellus sit amet tincidunt. Aliquam lacus est, pulvinar
+    non metus a, <b>facilisis</b> ultrices quam. Nulla feugiat leo in cursus eleifend. Suspendisse
+    eget nisi ac justo sagittis interdum id a ipsum. Nulla mauris justo, scelerisque ac
+    rutrum vitae, consequat vel ex.
+</p></p></p></p></p></p></p></p></p></p></p></p></p></p></p></p></p></p></p></p></p></p></p></p>
+<p>
+    Sed sollicitudin <b>sem</b> mauris, at rutrum nibh egestas vel. Ut eu nisi tellus. Praesent dignissim
+    orci elementum, mattis turpis eget, maximus ante. Suspendisse luctus eu felis a tempor. Morbi
+    ac risus vitae sem molestie ullamcorper. Curabitur ligula augue, sollicitudin quis maximus vel,
+    facilisis sed nibh. Aenean auctor magna sem, id rutrum metus convallis quis. Nullam non arcu
+    dictum, lobortis erat quis, rhoncus est. Suspendisse venenatis, mi sed venenatis vehicula,
+    tortor dolor egestas lectus, et efficitur turpis odio non augue. Integer velit sapien, dictum
+    non egestas vitae, hendrerit sed quam. Phasellus a nunc eu erat varius imperdiet. Etiam id
+    sollicitudin turpis, vitae molestie orci. Quisque ornare magna quis metus rhoncus commodo.
+    Phasellus non mauris velit.
+</p>
+<p>
+    Etiam dictum tellus ipsum, nec varius quam ornare vel. Cras vehicula diam nec sollicitudin
+    ultricies. Pellentesque rhoncus sagittis nisl id facilisis. Nunc viverra convallis risus ut
+    luctus. Aliquam vestibulum <b>efficitur massa</b>, id tempus nisi posuere a. Aliquam scelerisque
+    elit justo. Nullam a ante felis. Cras vitae lorem eu nisi feugiat hendrerit. Maecenas vitae
+    suscipit leo, lacinia dignissim lacus. Sed eget volutpat mi. In eu bibendum neque. Pellentesque
+    finibus velit a fermentum rhoncus. Maecenas leo purus, eleifend eu lacus a, condimentum sagittis
+    justo.
+</p>"#;
+    let string_short = "Lorem ipsum dolor sit amet,<foo>bar&foo\"bar\\foo/bar";
+    let empty = "";
+    let no_escape = "Lorem ipsum dolor sit amet,";
+    let no_escape_long = r#"
+Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin scelerisque eu urna in aliquet.
+Phasellus ac nulla a urna sagittis consequat id quis est. Nullam eu ex eget erat accumsan dictum
+ac lobortis urna. Etiam fermentum ut quam at dignissim. Curabitur vestibulum luctus tellus, sit
+amet lobortis augue tempor faucibus. Nullam sed felis eget odio elementum euismod in sit amet massa.
+Vestibulum sagittis purus sit amet eros auctor, sit amet pharetra purus dapibus. Donec ornare metus
+vel dictum porta. Etiam ut nisl nisi. Nullam rutrum porttitor mi. Donec aliquam ac ipsum eget
+hendrerit. Cras faucibus, eros ut pharetra imperdiet, est tellus aliquet felis, eget convallis
+lacus ipsum eget quam. Vivamus orci lorem, maximus ac mi eget, bibendum vulputate massa. In
+vestibulum dui hendrerit, vestibulum lacus sit amet, posuere erat. Vivamus euismod massa diam,
+vulputate euismod lectus vestibulum nec. Donec sit amet massa magna. Nunc ipsum nulla, euismod
+quis lacus at, gravida maximus elit. Duis tristique, nisl nullam.
+    "#;
+
+    b.iter(|| {
+        format!("{}", MarkupDisplay::new_unsafe(string_long, Html));
+        format!("{}", MarkupDisplay::new_unsafe(string_short, Html));
+        format!("{}", MarkupDisplay::new_unsafe(empty, Html));
+        format!("{}", MarkupDisplay::new_unsafe(no_escape, Html));
+        format!("{}", MarkupDisplay::new_unsafe(no_escape_long, Html));
+    });
+}
diff --git a/third_party/rust/askama_escape/src/lib.rs b/third_party/rust/askama_escape/src/lib.rs
new file mode 100644
index 0000000000..1788843086
--- /dev/null
+++ b/third_party/rust/askama_escape/src/lib.rs
@@ -0,0 +1,239 @@
+#![cfg_attr(not(any(feature = "json", test)), no_std)]
+#![deny(elided_lifetimes_in_paths)]
+#![deny(unreachable_pub)]
+
+use core::fmt::{self, Display, Formatter, Write};
+use core::str;
+
+#[derive(Debug)]
+pub struct MarkupDisplay<E, T>
+where
+    E: Escaper,
+    T: Display,
+{
+    value: DisplayValue<T>,
+    escaper: E,
+}
+
+impl<E, T> MarkupDisplay<E, T>
+where
+    E: Escaper,
+    T: Display,
+{
+    pub fn new_unsafe(value: T, escaper: E) -> Self {
+        Self {
+            value: DisplayValue::Unsafe(value),
+            escaper,
+        }
+    }
+
+    pub fn new_safe(value: T, escaper: E) -> Self {
+        Self {
+            value: DisplayValue::Safe(value),
+            escaper,
+        }
+    }
+
+    #[must_use]
+    pub fn mark_safe(mut self) -> MarkupDisplay<E, T> {
+        self.value = match self.value {
+            DisplayValue::Unsafe(t) => DisplayValue::Safe(t),
+            _ => self.value,
+        };
+        self
+    }
+}
+
+impl<E, T> Display for MarkupDisplay<E, T>
+where
+    E: Escaper,
+    T: Display,
+{
+    fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result {
+        match self.value {
+            DisplayValue::Unsafe(ref t) => write!(
+                EscapeWriter {
+                    fmt,
+                    escaper: &self.escaper
+                },
+                "{}",
+                t
+            ),
+            DisplayValue::Safe(ref t) => t.fmt(fmt),
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct EscapeWriter<'a, E, W> {
+    fmt: W,
+    escaper: &'a E,
+}
+
+impl<E, W> Write for EscapeWriter<'_, E, W>
+where
+    W: Write,
+    E: Escaper,
+{
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        self.escaper.write_escaped(&mut self.fmt, s)
+    }
+}
+
+pub fn escape<E>(string: &str, escaper: E) -> Escaped<'_, E>
+where
+    E: Escaper,
+{
+    Escaped { string, escaper }
+}
+
+#[derive(Debug)]
+pub struct Escaped<'a, E>
+where
+    E: Escaper,
+{
+    string: &'a str,
+    escaper: E,
+}
+
+impl<E> Display for Escaped<'_, E>
+where
+    E: Escaper,
+{
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.escaper.write_escaped(fmt, self.string)
+    }
+}
+
+pub struct Html;
+
+macro_rules! escaping_body {
+    ($start:ident, $i:ident, $fmt:ident, $bytes:ident, $quote:expr) => {{
+        if $start < $i {
+            $fmt.write_str(unsafe { str::from_utf8_unchecked(&$bytes[$start..$i]) })?;
+        }
+        $fmt.write_str($quote)?;
+        $start = $i + 1;
+    }};
+}
+
+impl Escaper for Html {
+    fn write_escaped<W>(&self, mut fmt: W, string: &str) -> fmt::Result
+    where
+        W: Write,
+    {
+        let bytes = string.as_bytes();
+        let mut start = 0;
+        for (i, b) in bytes.iter().enumerate() {
+            if b.wrapping_sub(b'"') <= FLAG {
+                match *b {
+                    b'<' => escaping_body!(start, i, fmt, bytes, "&lt;"),
+                    b'>' => escaping_body!(start, i, fmt, bytes, "&gt;"),
+                    b'&' => escaping_body!(start, i, fmt, bytes, "&amp;"),
+                    b'"' => escaping_body!(start, i, fmt, bytes, "&quot;"),
+                    b'\'' => escaping_body!(start, i, fmt, bytes, "&#x27;"),
+                    _ => (),
+                }
+            }
+        }
+        if start < bytes.len() {
+            fmt.write_str(unsafe { str::from_utf8_unchecked(&bytes[start..]) })
+        } else {
+            Ok(())
+        }
+    }
+}
+
+pub struct Text;
+
+impl Escaper for Text {
+    fn write_escaped<W>(&self, mut fmt: W, string: &str) -> fmt::Result
+    where
+        W: Write,
+    {
+        fmt.write_str(string)
+    }
+}
+
+#[derive(Debug, PartialEq)]
+enum DisplayValue<T>
+where
+    T: Display,
+{
+    Safe(T),
+    Unsafe(T),
+}
+
+pub trait Escaper {
+    fn write_escaped<W>(&self, fmt: W, string: &str) -> fmt::Result
+    where
+        W: Write;
+}
+
+const FLAG: u8 = b'>' - b'"';
+
+/// Escape chevrons, ampersand and apostrophes for use in JSON
+#[cfg(feature = "json")]
+#[derive(Debug, Clone, Default)]
+pub struct JsonEscapeBuffer(Vec<u8>);
+
+#[cfg(feature = "json")]
+impl JsonEscapeBuffer {
+    pub fn new() -> Self {
+        Self(Vec::new())
+    }
+
+    pub fn finish(self) -> String {
+        unsafe { String::from_utf8_unchecked(self.0) }
+    }
+}
+
+#[cfg(feature = "json")]
+impl std::io::Write for JsonEscapeBuffer {
+    fn write(&mut self, bytes: &[u8]) -> std::io::Result<usize> {
+        macro_rules! push_esc_sequence {
+            ($start:ident, $i:ident, $self:ident, $bytes:ident, $quote:expr) => {{
+                if $start < $i {
+                    $self.0.extend_from_slice(&$bytes[$start..$i]);
+                }
+                $self.0.extend_from_slice($quote);
+                $start = $i + 1;
+            }};
+        }
+
+        self.0.reserve(bytes.len());
+        let mut start = 0;
+        for (i, b) in bytes.iter().enumerate() {
+            match *b {
+                b'&' => push_esc_sequence!(start, i, self, bytes, br#"\u0026"#),
+                b'\'' => push_esc_sequence!(start, i, self, bytes, br#"\u0027"#),
+                b'<' => push_esc_sequence!(start, i, self, bytes, br#"\u003c"#),
+                b'>' => push_esc_sequence!(start, i, self, bytes, br#"\u003e"#),
+                _ => (),
+            }
+        }
+        if start < bytes.len() {
+            self.0.extend_from_slice(&bytes[start..]);
+        }
+        Ok(bytes.len())
+    }
+
+    fn flush(&mut self) -> std::io::Result<()> {
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::string::ToString;
+
+    #[test]
+    fn test_escape() {
+        assert_eq!(escape("", Html).to_string(), "");
+        assert_eq!(escape("<&>", Html).to_string(), "&lt;&amp;&gt;");
+        assert_eq!(escape("bla&", Html).to_string(), "bla&amp;");
+        assert_eq!(escape("<foo", Html).to_string(), "&lt;foo");
+        assert_eq!(escape("bla&h", Html).to_string(), "bla&amp;h");
+    }
+}