Merging upstream version 1.72.1+dfsg1.

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

6 files changed, 191 insertions, 167 deletions

diff --git a/vendor/iana-time-zone/.cargo-checksum.json b/vendor/iana-time-zone/.cargo-checksum.json
index 1ff051c20..356725a06 100644
--- a/vendor/iana-time-zone/.cargo-checksum.json
+++ b/vendor/iana-time-zone/.cargo-checksum.json
@@ -1 +1 @@
-{"files":{"CHANGELOG.md":"6002d865cdaa676f19ab808b8545bb1e8993a6778e549a6ea187dd3dc743baa9","Cargo.lock":"c4aa3f484b70d79c93718b0118d0fdd175d2737a1756e5e4cb80fa17c0aaecac","Cargo.toml":"d05222cc7ad10943b33bc95d7e6e116dd9689a3e498909257c460ce5090f2038","LICENSE-APACHE":"696759d65dfe558ff7d9f031c76db19ec5c0767470fb67c4e8d990820d1e99c9","LICENSE-MIT":"da28ccc6b158fc2d8cccc74e99794b1cff1d29bd7bbeb019442fcf0c04c6cad9","README.md":"c5531c44131c4b4473a747d6eab8868d31964da70af6264650253212df5ba9f4","examples/get_timezone.rs":"c4db7b1cc71c7b3728ddd70e76c0dbd40239c6b1b8c705cb63476757d3177dec","examples/stress-test.rs":"3ad469de5a650389699c9ffe5fd78af2bdd46e7140cc05391c60d793fc6f8e98","src/ffi_utils.rs":"bfbd155b004c2fc4e793aec4604c7b353f71caf35bf67e9b34cd07349628571f","src/lib.rs":"ed60b3581f02879544d87be98764f439676a1b88da7d927c7ec4a785295ec114","src/platform.rs":"bef2c3ead64d498cefedc2555194bb492db06e3d49423bdcdec5f6c5696cf091","src/tz_android.rs":"3da37f1b87f87a0ed215734f2b373b2d187bcf49386adfe8bfff207f9a5e8fe2","src/tz_freebsd.rs":"4247af5c6dd0712705186ed54d789193c64139f707af316d4fde86aa1e2a1b13","src/tz_haiku.rs":"761afd80301683a44bf937bbf6b13c5c792af42ed7037623bbeccbab6d0aa8fc","src/tz_illumos.rs":"375ae951d1417f63e6d77c9add7f7f646f24c0054cb8407bd4b9f06907494888","src/tz_linux.rs":"7bbc921fcbc71d87c5527b45f7d44963fcef5a6f2a015b78a858cf441c9e1727","src/tz_macos.rs":"081d5e60955268a1b6949089354eb6657de1c2eb569a69f4e094b995270d540d","src/tz_netbsd.rs":"ec278bbe1cb5f648c063ec23bff6081146454b9f6aa3918b9ca50b8804d5838f","src/tz_wasm32.rs":"10aa33caa86645a16e2126fe1a86dda2b57f63caa9addcd726245fbc9657dc1b","src/tz_windows.rs":"9cafe592b28505c9d2bb9adfb2924c877f1fc2685ee2be2b1e68ed45f64553f1"},"package":"0722cd7114b7de04316e7ea5456a0bbb20e4adb46fd27a3697adb812cff0f37c"}
\ No newline at end of file
+{"files":{"CHANGELOG.md":"93004e88d2fd9de0e3ade9be46ff05ce1831d82429894bb92a9fa7d17982885f","Cargo.lock":"b18d1c32cd6a0933a4b86f163a2f46e115716076978c38121933d472e7239f1e","Cargo.toml":"d30a9e40142079ee0d529522f2912604f4679c80d61bdecdf840ec338d245ebf","LICENSE-APACHE":"696759d65dfe558ff7d9f031c76db19ec5c0767470fb67c4e8d990820d1e99c9","LICENSE-MIT":"da28ccc6b158fc2d8cccc74e99794b1cff1d29bd7bbeb019442fcf0c04c6cad9","README.md":"c5531c44131c4b4473a747d6eab8868d31964da70af6264650253212df5ba9f4","examples/get_timezone.rs":"c4db7b1cc71c7b3728ddd70e76c0dbd40239c6b1b8c705cb63476757d3177dec","examples/stress-test.rs":"3ad469de5a650389699c9ffe5fd78af2bdd46e7140cc05391c60d793fc6f8e98","src/ffi_utils.rs":"bfbd155b004c2fc4e793aec4604c7b353f71caf35bf67e9b34cd07349628571f","src/lib.rs":"ed60b3581f02879544d87be98764f439676a1b88da7d927c7ec4a785295ec114","src/platform.rs":"1748faef9b3f42f12b882d7e67e3792096400dc83fee024d85457aae668558f8","src/tz_android.rs":"3da37f1b87f87a0ed215734f2b373b2d187bcf49386adfe8bfff207f9a5e8fe2","src/tz_freebsd.rs":"4247af5c6dd0712705186ed54d789193c64139f707af316d4fde86aa1e2a1b13","src/tz_haiku.rs":"761afd80301683a44bf937bbf6b13c5c792af42ed7037623bbeccbab6d0aa8fc","src/tz_illumos.rs":"375ae951d1417f63e6d77c9add7f7f646f24c0054cb8407bd4b9f06907494888","src/tz_linux.rs":"3f04dbc1345ef6783881f3ff9aef4449819dbdc8a1578ffad69c03dc65623f9a","src/tz_macos.rs":"081d5e60955268a1b6949089354eb6657de1c2eb569a69f4e094b995270d540d","src/tz_netbsd.rs":"ec278bbe1cb5f648c063ec23bff6081146454b9f6aa3918b9ca50b8804d5838f","src/tz_wasm32.rs":"10aa33caa86645a16e2126fe1a86dda2b57f63caa9addcd726245fbc9657dc1b","src/tz_windows.rs":"9cafe592b28505c9d2bb9adfb2924c877f1fc2685ee2be2b1e68ed45f64553f1"},"package":"2fad5b825842d2b38bd206f3e81d6957625fd7f0a361e345c30e01a0ae2dd613"}
\ No newline at end of file
diff --git a/vendor/iana-time-zone/CHANGELOG.md b/vendor/iana-time-zone/CHANGELOG.md
index 81159ca28..588e76111 100644
--- a/vendor/iana-time-zone/CHANGELOG.md
+++ b/vendor/iana-time-zone/CHANGELOG.md
@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.1.57] - 2023-06-07
+### Changed
+- implement OpenWRT support ([#109](https://github.com/strawlab/iana-time-zone/pull/109))
+
 ## [0.1.56] - 2023-04-03
 ### Changed
 - update `windows` dependency ([#102](https://github.com/strawlab/iana-time-zone/pull/102))
diff --git a/vendor/iana-time-zone/Cargo.lock b/vendor/iana-time-zone/Cargo.lock
index b5d89dc35..18c3350bd 100644
--- a/vendor/iana-time-zone/Cargo.lock
+++ b/vendor/iana-time-zone/Cargo.lock
@@ -13,9 +13,9 @@ dependencies = [
 
 [[package]]
 name = "bumpalo"
-version = "3.11.0"
+version = "3.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c1ad822118d20d2c234f427000d5acc36eabe1e29a348c89b63dd60b13f28e5d"
+checksum = "a3e2c3daef883ecc1b5d58c15adae93470a91d425f3532ba1695849656af3fc1"
 
 [[package]]
 name = "cc"
@@ -30,16 +30,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
-name = "codespan-reporting"
-version = "0.11.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3538270d33cc669650c4b093848450d380def10c331d38c768e34cac80576e6e"
-dependencies = [
- "termcolor",
- "unicode-width",
-]
-
-[[package]]
 name = "console_error_panic_hook"
 version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -51,57 +41,13 @@ dependencies = [
 
 [[package]]
 name = "core-foundation-sys"
-version = "0.8.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5827cebf4670468b8772dd191856768aedcb1b0278a04f989f7766351917b9dc"
-
-[[package]]
-name = "cxx"
-version = "1.0.92"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a140f260e6f3f79013b8bfc65e7ce630c9ab4388c6a89c71e07226f49487b72"
-dependencies = [
- "cc",
- "cxxbridge-flags",
- "cxxbridge-macro",
- "link-cplusplus",
-]
-
-[[package]]
-name = "cxx-build"
-version = "1.0.92"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "da6383f459341ea689374bf0a42979739dc421874f112ff26f829b8040b8e613"
-dependencies = [
- "cc",
- "codespan-reporting",
- "once_cell",
- "proc-macro2",
- "quote",
- "scratch",
- "syn",
-]
-
-[[package]]
-name = "cxxbridge-flags"
-version = "1.0.92"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "90201c1a650e95ccff1c8c0bb5a343213bdd317c6e600a93075bca2eff54ec97"
-
-[[package]]
-name = "cxxbridge-macro"
-version = "1.0.92"
+version = "0.8.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b75aed41bb2e6367cae39e6326ef817a851db13c13e4f3263714ca3cfb8de56"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
+checksum = "e496a50fda8aacccc86d7529e2c1e0892dbd0f898a6b5645b5561b89c3210efa"
 
 [[package]]
 name = "iana-time-zone"
-version = "0.1.56"
+version = "0.1.57"
 dependencies = [
  "android_system_properties",
  "core-foundation-sys",
@@ -114,88 +60,69 @@ dependencies = [
 
 [[package]]
 name = "iana-time-zone-haiku"
-version = "0.1.1"
+version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0703ae284fc167426161c2e3f1da3ea71d94b21bedbcc9494e92b28e334e3dca"
+checksum = "f31827a206f56af32e590ba56d5d2d085f558508192593743f16b2306495269f"
 dependencies = [
- "cxx",
- "cxx-build",
+ "cc",
 ]
 
 [[package]]
 name = "js-sys"
-version = "0.3.60"
+version = "0.3.63"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "49409df3e3bf0856b916e2ceaca09ee28e6871cf7d9ce97a692cacfdb2a25a47"
+checksum = "2f37a4a5928311ac501dee68b3c7613a1037d0edb30c8e5427bd832d55d1b790"
 dependencies = [
  "wasm-bindgen",
 ]
 
 [[package]]
 name = "libc"
-version = "0.2.132"
+version = "0.2.146"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8371e4e5341c3a96db127eb2465ac681ced4c433e01dd0e938adbef26ba93ba5"
-
-[[package]]
-name = "link-cplusplus"
-version = "1.0.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ecd207c9c713c34f95a097a5b029ac2ce6010530c7b49d7fea24d977dede04f5"
-dependencies = [
- "cc",
-]
+checksum = "f92be4933c13fd498862a9e02a3055f8a8d9c039ce33db97306fd5a6caa7f29b"
 
 [[package]]
 name = "log"
-version = "0.4.17"
+version = "0.4.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "abb12e687cfb44aa40f41fc3978ef76448f9b6038cad6aef4259d3c095a2382e"
-dependencies = [
- "cfg-if",
-]
+checksum = "518ef76f2f87365916b142844c16d8fefd85039bc5699050210a7778ee1cd1de"
 
 [[package]]
 name = "once_cell"
-version = "1.14.0"
+version = "1.18.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2f7254b99e31cad77da24b08ebf628882739a608578bb1bcdfc1f9c21260d7c0"
+checksum = "dd8b5dd2ae5ed71462c540258bedcb51965123ad7e7ccf4b9a8cafaa4a63576d"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.43"
+version = "1.0.59"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0a2ca2c61bc9f3d74d2886294ab7b9853abd9c1ad903a3ac7815c58989bb7bab"
+checksum = "6aeca18b86b413c660b781aa319e4e2648a3e6f9eadc9b47e9038e6fe9f3451b"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.21"
+version = "1.0.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bbe448f377a7d6961e30f5955f9b8d106c3f5e449d493ee1b125c1d43c2b5179"
+checksum = "1b9ab9c7eadfd8df19006f1cf1a4aed13540ed5cbc047010ece5826e10825488"
 dependencies = [
  "proc-macro2",
 ]
 
 [[package]]
 name = "scoped-tls"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ea6a9290e3c9cf0f18145ef7ffa62d68ee0bf5fcd651017e586dc7fd5da448c2"
-
-[[package]]
-name = "scratch"
-version = "1.0.5"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1792db035ce95be60c3f8853017b3999209281c24e2ba5bc8e59bf97a0c590c1"
+checksum = "e1cf6437eb19a8f4a6cc0f7dca544973b0b78843adbfeb3683d1a94a0024a294"
 
 [[package]]
 name = "syn"
-version = "1.0.99"
+version = "2.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "58dbef6ec655055e20b86b15a8cc6d439cca19b667537ac6a1369572d151ab13"
+checksum = "32d41677bcbe24c20c52e7c70b0d8db04134c5d1066bf98662e2871ad200ea3e"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -203,31 +130,16 @@ dependencies = [
 ]
 
 [[package]]
-name = "termcolor"
-version = "1.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "be55cf8942feac5c765c2c993422806843c9a9a45d4d5c407ad6dd2ea95eb9b6"
-dependencies = [
- "winapi-util",
-]
-
-[[package]]
 name = "unicode-ident"
-version = "1.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c4f5b37a154999a8f3f98cc23a628d850e154479cd94decf3414696e12e31aaf"
-
-[[package]]
-name = "unicode-width"
-version = "0.1.10"
+version = "1.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0edd1e5b14653f783770bce4a4dabb4a5108a5370a5f5d8cfe8710c361f6c8b"
+checksum = "b15811caf2415fb889178633e7724bad2509101cde276048e013b9def5e51fa0"
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.83"
+version = "0.2.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eaf9f5aceeec8be17c128b2e93e031fb8a4d469bb9c4ae2d7dc1888b26887268"
+checksum = "5bba0e8cb82ba49ff4e229459ff22a191bbe9a1cb3a341610c9c33efc27ddf73"
 dependencies = [
  "cfg-if",
  "wasm-bindgen-macro",
@@ -235,9 +147,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.83"
+version = "0.2.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4c8ffb332579b0557b52d268b91feab8df3615f265d5270fec2a8c95b17c1142"
+checksum = "19b04bc93f9d6bdee709f6bd2118f57dd6679cf1176a1af464fca3ab0d66d8fb"
 dependencies = [
  "bumpalo",
  "log",
@@ -250,9 +162,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-futures"
-version = "0.4.33"
+version = "0.4.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "23639446165ca5a5de86ae1d8896b737ae80319560fbaa4c2887b7da6e7ebd7d"
+checksum = "2d1985d03709c53167ce907ff394f5316aa22cb4e12761295c5dc57dacb6297e"
 dependencies = [
  "cfg-if",
  "js-sys",
@@ -262,9 +174,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.83"
+version = "0.2.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "052be0f94026e6cbc75cdefc9bae13fd6052cdcaf532fa6c45e7ae33a1e6c810"
+checksum = "14d6b024f1a526bb0234f52840389927257beb670610081360e5a03c5df9c258"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -272,9 +184,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.83"
+version = "0.2.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "07bc0c051dc5f23e307b13285f9d75df86bfdf816c5721e573dec1f9b8aa193c"
+checksum = "e128beba882dd1eb6200e1dc92ae6c5dbaa4311aa7bb211ca035779e5efc39f8"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -285,15 +197,15 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.83"
+version = "0.2.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1c38c045535d93ec4f0b4defec448e4291638ee608530863b1e2ba115d4fff7f"
+checksum = "ed9d5b4305409d1fc9482fee2d7f9bcbf24b3972bf59817ef757e23982242a93"
 
 [[package]]
 name = "wasm-bindgen-test"
-version = "0.3.33"
+version = "0.3.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "09d2fff962180c3fadf677438054b1db62bee4aa32af26a45388af07d1287e1d"
+checksum = "c9e636f3a428ff62b3742ebc3c70e254dfe12b8c2b469d688ea59cdd4abcf502"
 dependencies = [
  "console_error_panic_hook",
  "js-sys",
@@ -305,9 +217,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-test-macro"
-version = "0.3.33"
+version = "0.3.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4683da3dfc016f704c9f82cf401520c4f1cb3ee440f7f52b3d6ac29506a49ca7"
+checksum = "f18c1fad2f7c4958e7bcce014fa212f59a65d5e3721d0f77e6c0b27ede936ba3"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -315,46 +227,15 @@ dependencies = [
 
 [[package]]
 name = "web-sys"
-version = "0.3.60"
+version = "0.3.63"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bcda906d8be16e728fd5adc5b729afad4e444e106ab28cd1c7256e54fa61510f"
+checksum = "3bdd9ef4e984da1187bf8110c5cf5b845fbc87a23602cdf912386a76fcd3a7c2"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
 ]
 
 [[package]]
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-version = "0.3.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
-dependencies = [
- "winapi-i686-pc-windows-gnu",
- "winapi-x86_64-pc-windows-gnu",
-]
-
-[[package]]
-name = "winapi-i686-pc-windows-gnu"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
-
-[[package]]
-name = "winapi-util"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70ec6ce85bb158151cae5e5c87f95a8e97d2c0c4b001223f33a334e3ce5de178"
-dependencies = [
- "winapi",
-]
-
-[[package]]
-name = "winapi-x86_64-pc-windows-gnu"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
-
-[[package]]
 name = "windows"
 version = "0.48.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/vendor/iana-time-zone/Cargo.toml b/vendor/iana-time-zone/Cargo.toml
index 5cdc175a7..e06c7055b 100644
--- a/vendor/iana-time-zone/Cargo.toml
+++ b/vendor/iana-time-zone/Cargo.toml
@@ -12,7 +12,7 @@
 [package]
 edition = "2018"
 name = "iana-time-zone"
-version = "0.1.56"
+version = "0.1.57"
 authors = [
     "Andrew Straw <strawman@astraw.com>",
     "René Kijewski <rene.kijewski@fu-berlin.de>",
diff --git a/vendor/iana-time-zone/src/platform.rs b/vendor/iana-time-zone/src/platform.rs
index 5992bf377..d5ba0ee34 100644
--- a/vendor/iana-time-zone/src/platform.rs
+++ b/vendor/iana-time-zone/src/platform.rs
@@ -1,4 +1,4 @@
-pub fn get_timezone_inner() -> std::result::Result<String, crate::GetTimezoneError> {
+pub fn get_timezone_inner() -> Result<String, crate::GetTimezoneError> {
     Err(crate::GetTimezoneError::OsError)
 }
 
diff --git a/vendor/iana-time-zone/src/tz_linux.rs b/vendor/iana-time-zone/src/tz_linux.rs
index c1133e1cd..c0548ec09 100644
--- a/vendor/iana-time-zone/src/tz_linux.rs
+++ b/vendor/iana-time-zone/src/tz_linux.rs
@@ -1,7 +1,9 @@
 use std::fs::{read_link, read_to_string};
 
 pub(crate) fn get_timezone_inner() -> Result<String, crate::GetTimezoneError> {
-    etc_localtime().or_else(|_| etc_timezone())
+    etc_localtime()
+        .or_else(|_| etc_timezone())
+        .or_else(|_| openwrt::etc_config_system())
 }
 
 fn etc_timezone() -> Result<String, crate::GetTimezoneError> {
@@ -43,3 +45,140 @@ fn etc_localtime() -> Result<String, crate::GetTimezoneError> {
     }
     Err(crate::GetTimezoneError::FailedParsingString)
 }
+
+mod openwrt {
+    use std::io::BufRead;
+    use std::{fs, io, iter};
+
+    pub(crate) fn etc_config_system() -> Result<String, crate::GetTimezoneError> {
+        let f = fs::OpenOptions::new()
+            .read(true)
+            .open("/etc/config/system")?;
+        let mut f = io::BufReader::new(f);
+        let mut in_system_section = false;
+        let mut line = String::with_capacity(80);
+
+        // prefer option "zonename" (IANA time zone) over option "timezone" (POSIX time zone)
+        let mut timezone = None;
+        loop {
+            line.clear();
+            f.read_line(&mut line)?;
+            if line.is_empty() {
+                break;
+            }
+
+            let mut iter = IterWords(&line);
+            let mut next = || iter.next().transpose();
+
+            if let Some(keyword) = next()? {
+                if keyword == "config" {
+                    in_system_section = next()? == Some("system") && next()?.is_none();
+                } else if in_system_section && keyword == "option" {
+                    if let Some(key) = next()? {
+                        if key == "zonename" {
+                            if let (Some(zonename), None) = (next()?, next()?) {
+                                return Ok(zonename.to_owned());
+                            }
+                        } else if key == "timezone" {
+                            if let (Some(value), None) = (next()?, next()?) {
+                                timezone = Some(value.to_owned());
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        timezone.ok_or_else(|| crate::GetTimezoneError::OsError)
+    }
+
+    #[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
+    struct BrokenQuote;
+
+    impl From<BrokenQuote> for crate::GetTimezoneError {
+        fn from(_: BrokenQuote) -> Self {
+            crate::GetTimezoneError::FailedParsingString
+        }
+    }
+
+    /// Iterated over all words in a OpenWRT config line.
+    struct IterWords<'a>(&'a str);
+
+    impl<'a> Iterator for IterWords<'a> {
+        type Item = Result<&'a str, BrokenQuote>;
+
+        fn next(&mut self) -> Option<Self::Item> {
+            match read_word(self.0) {
+                Ok(Some((item, tail))) => {
+                    self.0 = tail;
+                    Some(Ok(item))
+                }
+                Ok(None) => {
+                    self.0 = "";
+                    None
+                }
+                Err(err) => {
+                    self.0 = "";
+                    Some(Err(err))
+                }
+            }
+        }
+    }
+
+    impl iter::FusedIterator for IterWords<'_> {}
+
+    /// Read the next word in a OpenWRT config line. Strip any surrounding quotation marks.
+    ///
+    /// Returns
+    ///
+    ///  * a tuple `Some((word, remaining_line))` if found,
+    ///  * `None` if the line is exhausted, or
+    ///  * `Err(BrokenQuote)` if the line could not be parsed.
+    #[allow(clippy::manual_strip)] // needs to be compatile to 1.36
+    fn read_word(s: &str) -> Result<Option<(&str, &str)>, BrokenQuote> {
+        let s = s.trim_start();
+        if s.is_empty() || s.starts_with('#') {
+            Ok(None)
+        } else if s.starts_with('\'') {
+            let mut iter = s[1..].splitn(2, '\'');
+            match (iter.next(), iter.next()) {
+                (Some(item), Some(tail)) => Ok(Some((item, tail))),
+                _ => Err(BrokenQuote),
+            }
+        } else if s.starts_with('"') {
+            let mut iter = s[1..].splitn(2, '"');
+            match (iter.next(), iter.next()) {
+                (Some(item), Some(tail)) => Ok(Some((item, tail))),
+                _ => Err(BrokenQuote),
+            }
+        } else {
+            let mut iter = s.splitn(2, |c: char| c.is_whitespace());
+            match (iter.next(), iter.next()) {
+                (Some(item), Some(tail)) => Ok(Some((item, tail))),
+                _ => Ok(Some((s, ""))),
+            }
+        }
+    }
+
+    #[cfg(test)]
+    #[test]
+    fn test_read_word() {
+        assert_eq!(
+            read_word("       option timezone 'CST-8'\n").unwrap(),
+            Some(("option", "timezone 'CST-8'\n")),
+        );
+        assert_eq!(
+            read_word("timezone 'CST-8'\n").unwrap(),
+            Some(("timezone", "'CST-8'\n")),
+        );
+        assert_eq!(read_word("'CST-8'\n").unwrap(), Some(("CST-8", "\n")));
+        assert_eq!(read_word("\n").unwrap(), None);
+
+        assert_eq!(
+            read_word(r#""time 'Zone'""#).unwrap(),
+            Some(("time 'Zone'", "")),
+        );
+
+        assert_eq!(read_word("'CST-8").unwrap_err(), BrokenQuote);
+    }
+}