Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

15 files changed, 2027 insertions, 0 deletions

diff --git a/third_party/rust/serde_urlencoded/.cargo-checksum.json b/third_party/rust/serde_urlencoded/.cargo-checksum.json
new file mode 100644
index 0000000000..126414d161
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{"Cargo.toml":"776416273e0e2004aaf8869df552bd0ff39858184730540604dad69e4dd17873","LICENSE-APACHE":"62c7a1e35f56406896d7aa7ca52d0cc0d272ac022b5d2796e7d6905db8a3636a","LICENSE-MIT":"b9eb266294324f672cbe945fe8f2e32f85024f0d61a1a7d14382cdde0ac44769","README.md":"0adc2e76e529922436075eddeaaf8decf04f1a642f0e6d9c513b634e72c00699","rustfmt.toml":"5dab9ecd7e76bc1f49cc5a6985196912b9ac8086dfb70833b6251721ba5bf74c","src/de.rs":"3e7ed20d227e2dab88c201f9fda80ebc39b8219fe66ceaf6bef478ca5c9bd891","src/lib.rs":"83718fe61b847408cd08da3515ce4f4ec45998615605b6e878461313986d8571","src/ser/key.rs":"4651a34088cf08b948b27e885efe5c1f6876dbd70f502892bbb7710ce76c878f","src/ser/mod.rs":"2a2eeaf30790e24fbee6bb2ba140dc29343ef797bf3668587892f2c6d2644648","src/ser/pair.rs":"be19e319092dba66aac06bae47f77d2ef39c4c308bbd67c13d031ab88c0e68e7","src/ser/part.rs":"8da25ff5a5159a05dd4b221a757aac514975243b4860aa5eee4ad4500a46d48b","src/ser/value.rs":"5eacb91e054476b982c5fa1b0b38179e844ca79842170d47665aca9e4515552a","tests/test_deserialize.rs":"4525a4d05fd86b2535d50857adab101a02bb5c61a6cb9c138513c8687eca32a7","tests/test_serialize.rs":"2f57ffda172d84573c5d9abe2d700b756fa844639ff0f1bf295441429ddd662b"},"package":"d3491c14715ca2294c4d6a88f15e84739788c1d030eed8c110436aafdaa2f3fd"}
\ No newline at end of file
diff --git a/third_party/rust/serde_urlencoded/Cargo.toml b/third_party/rust/serde_urlencoded/Cargo.toml
new file mode 100644
index 0000000000..dfe8cc1ff2
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/Cargo.toml
@@ -0,0 +1,41 @@
+# 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 = "serde_urlencoded"
+version = "0.7.1"
+authors = ["Anthony Ramine <n.oxyde@gmail.com>"]
+exclude = ["/.travis.yml", "/bors.toml"]
+description = "`x-www-form-urlencoded` meets Serde"
+documentation = "https://docs.rs/serde_urlencoded/0.7.1/serde_urlencoded/"
+keywords = ["serde", "serialization", "urlencoded"]
+categories = ["encoding", "web-programming"]
+license = "MIT/Apache-2.0"
+repository = "https://github.com/nox/serde_urlencoded"
+
+[lib]
+test = false
+[dependencies.form_urlencoded]
+version = "1"
+
+[dependencies.itoa]
+version = "1"
+
+[dependencies.ryu]
+version = "1"
+
+[dependencies.serde]
+version = "1.0.69"
+[dev-dependencies.serde_derive]
+version = "1"
+[badges.travis-ci]
+repository = "nox/serde_urlencoded"
diff --git a/third_party/rust/serde_urlencoded/LICENSE-APACHE b/third_party/rust/serde_urlencoded/LICENSE-APACHE
new file mode 100644
index 0000000000..1b5ec8b78e
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/LICENSE-APACHE
@@ -0,0 +1,176 @@
+                              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
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+   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
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+   including but not limited to software source code, documentation
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+
+   "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
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+
+   "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.
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+   "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
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+2. Grant of Copyright License. Subject to the terms and conditions of
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+4. Redistribution. You may reproduce and distribute copies of the
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+
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+       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
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+       that such additional attribution notices cannot be construed
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+   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,
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+   implied, including, without limitation, any warranties or conditions
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+   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
diff --git a/third_party/rust/serde_urlencoded/LICENSE-MIT b/third_party/rust/serde_urlencoded/LICENSE-MIT
new file mode 100644
index 0000000000..39f6303ad3
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/LICENSE-MIT
@@ -0,0 +1,25 @@
+Copyright (c) 2016 Anthony Ramine
+
+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/serde_urlencoded/README.md b/third_party/rust/serde_urlencoded/README.md
new file mode 100644
index 0000000000..92cacb65b8
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/README.md
@@ -0,0 +1,53 @@
+`x-www-form-urlencoded` meets Serde
+===================================
+
+This crate is a Rust library for serialising to and deserialising from
+the [`application/x-www-form-urlencoded`][urlencoded] format. It is built
+upon [Serde], a high performance generic serialization framework and [rust-url],
+a URL parser for Rust.
+
+[rust-url]: https://github.com/servo/rust-url
+[Serde]: https://github.com/serde-rs/serde
+[urlencoded]: https://url.spec.whatwg.org/#application/x-www-form-urlencoded
+
+Installation
+============
+
+This crate works with Cargo and can be found on
+[crates.io] with a `Cargo.toml` like:
+
+```toml
+[dependencies]
+serde_urlencoded = "0.7"
+```
+
+The documentation is available on [docs.rs].
+
+[crates.io]: https://crates.io/crates/serde_urlencoded
+[docs.rs]: https://docs.rs/serde_urlencoded/0.7.1/serde_urlencoded/
+
+## Getting help
+
+Serde developers live in the #serde channel on
+[`irc.mozilla.org`](https://wiki.mozilla.org/IRC) and most rust-url developers
+live in the #servo one. The #rust channel is also a good resource with generally
+faster response time but less specific knowledge about Serde, rust-url or this
+crate. If IRC is not your thing, we are happy to respond to [GitHub
+issues](https://github.com/nox/serde_urlencoded/issues/new) as well.
+
+## License
+
+serde_urlencoded is 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 serde_urlencoded 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/serde_urlencoded/rustfmt.toml b/third_party/rust/serde_urlencoded/rustfmt.toml
new file mode 100644
index 0000000000..f80ce4e9c8
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/rustfmt.toml
@@ -0,0 +1,5 @@
+match_block_trailing_comma = false
+max_width = 80
+newline_style = "Unix"
+reorder_imports = true
+use_try_shorthand = true
diff --git a/third_party/rust/serde_urlencoded/src/de.rs b/third_party/rust/serde_urlencoded/src/de.rs
new file mode 100644
index 0000000000..d906eaae2a
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/src/de.rs
@@ -0,0 +1,321 @@
+//! Deserialization support for the `application/x-www-form-urlencoded` format.
+
+use form_urlencoded::parse;
+use form_urlencoded::Parse as UrlEncodedParse;
+use serde::de::value::MapDeserializer;
+use serde::de::Error as de_Error;
+use serde::de::{self, IntoDeserializer};
+use serde::forward_to_deserialize_any;
+use std::borrow::Cow;
+use std::io::Read;
+
+#[doc(inline)]
+pub use serde::de::value::Error;
+
+/// Deserializes a `application/x-www-form-urlencoded` value from a `&[u8]`.
+///
+/// ```
+/// let meal = vec![
+///     ("bread".to_owned(), "baguette".to_owned()),
+///     ("cheese".to_owned(), "comté".to_owned()),
+///     ("meat".to_owned(), "ham".to_owned()),
+///     ("fat".to_owned(), "butter".to_owned()),
+/// ];
+///
+/// assert_eq!(
+///     serde_urlencoded::from_bytes::<Vec<(String, String)>>(
+///         b"bread=baguette&cheese=comt%C3%A9&meat=ham&fat=butter"),
+///     Ok(meal));
+/// ```
+pub fn from_bytes<'de, T>(input: &'de [u8]) -> Result<T, Error>
+where
+    T: de::Deserialize<'de>,
+{
+    T::deserialize(Deserializer::new(parse(input)))
+}
+
+/// Deserializes a `application/x-www-form-urlencoded` value from a `&str`.
+///
+/// ```
+/// let meal = vec![
+///     ("bread".to_owned(), "baguette".to_owned()),
+///     ("cheese".to_owned(), "comté".to_owned()),
+///     ("meat".to_owned(), "ham".to_owned()),
+///     ("fat".to_owned(), "butter".to_owned()),
+/// ];
+///
+/// assert_eq!(
+///     serde_urlencoded::from_str::<Vec<(String, String)>>(
+///         "bread=baguette&cheese=comt%C3%A9&meat=ham&fat=butter"),
+///     Ok(meal));
+/// ```
+pub fn from_str<'de, T>(input: &'de str) -> Result<T, Error>
+where
+    T: de::Deserialize<'de>,
+{
+    from_bytes(input.as_bytes())
+}
+
+/// Convenience function that reads all bytes from `reader` and deserializes
+/// them with `from_bytes`.
+pub fn from_reader<T, R>(mut reader: R) -> Result<T, Error>
+where
+    T: de::DeserializeOwned,
+    R: Read,
+{
+    let mut buf = vec![];
+    reader.read_to_end(&mut buf).map_err(|e| {
+        de::Error::custom(format_args!("could not read input: {}", e))
+    })?;
+    from_bytes(&buf)
+}
+
+/// A deserializer for the `application/x-www-form-urlencoded` format.
+///
+/// * Supported top-level outputs are structs, maps and sequences of pairs,
+///   with or without a given length.
+///
+/// * Main `deserialize` methods defers to `deserialize_map`.
+///
+/// * Everything else but `deserialize_seq` and `deserialize_seq_fixed_size`
+///   defers to `deserialize`.
+pub struct Deserializer<'de> {
+    inner: MapDeserializer<'de, PartIterator<'de>, Error>,
+}
+
+impl<'de> Deserializer<'de> {
+    /// Returns a new `Deserializer`.
+    pub fn new(parser: UrlEncodedParse<'de>) -> Self {
+        Deserializer {
+            inner: MapDeserializer::new(PartIterator(parser)),
+        }
+    }
+}
+
+impl<'de> de::Deserializer<'de> for Deserializer<'de> {
+    type Error = Error;
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.deserialize_map(visitor)
+    }
+
+    fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        visitor.visit_map(self.inner)
+    }
+
+    fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        visitor.visit_seq(self.inner)
+    }
+
+    fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        self.inner.end()?;
+        visitor.visit_unit()
+    }
+
+    forward_to_deserialize_any! {
+        bool
+        u8
+        u16
+        u32
+        u64
+        i8
+        i16
+        i32
+        i64
+        f32
+        f64
+        char
+        str
+        string
+        option
+        bytes
+        byte_buf
+        unit_struct
+        newtype_struct
+        tuple_struct
+        struct
+        identifier
+        tuple
+        enum
+        ignored_any
+    }
+}
+
+struct PartIterator<'de>(UrlEncodedParse<'de>);
+
+impl<'de> Iterator for PartIterator<'de> {
+    type Item = (Part<'de>, Part<'de>);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.0.next().map(|(k, v)| (Part(k), Part(v)))
+    }
+}
+
+struct Part<'de>(Cow<'de, str>);
+
+impl<'de> IntoDeserializer<'de> for Part<'de> {
+    type Deserializer = Self;
+
+    fn into_deserializer(self) -> Self::Deserializer {
+        self
+    }
+}
+
+macro_rules! forward_parsed_value {
+    ($($ty:ident => $method:ident,)*) => {
+        $(
+            fn $method<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+                where V: de::Visitor<'de>
+            {
+                match self.0.parse::<$ty>() {
+                    Ok(val) => val.into_deserializer().$method(visitor),
+                    Err(e) => Err(de::Error::custom(e))
+                }
+            }
+        )*
+    }
+}
+
+impl<'de> de::Deserializer<'de> for Part<'de> {
+    type Error = Error;
+
+    fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        match self.0 {
+            Cow::Borrowed(value) => visitor.visit_borrowed_str(value),
+            Cow::Owned(value) => visitor.visit_string(value),
+        }
+    }
+
+    fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        visitor.visit_some(self)
+    }
+
+    fn deserialize_enum<V>(
+        self,
+        _name: &'static str,
+        _variants: &'static [&'static str],
+        visitor: V,
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        visitor.visit_enum(ValueEnumAccess(self.0))
+    }
+
+    fn deserialize_newtype_struct<V>(
+        self,
+        _name: &'static str,
+        visitor: V,
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        visitor.visit_newtype_struct(self)
+    }
+
+    forward_to_deserialize_any! {
+        char
+        str
+        string
+        unit
+        bytes
+        byte_buf
+        unit_struct
+        tuple_struct
+        struct
+        identifier
+        tuple
+        ignored_any
+        seq
+        map
+    }
+
+    forward_parsed_value! {
+        bool => deserialize_bool,
+        u8 => deserialize_u8,
+        u16 => deserialize_u16,
+        u32 => deserialize_u32,
+        u64 => deserialize_u64,
+        i8 => deserialize_i8,
+        i16 => deserialize_i16,
+        i32 => deserialize_i32,
+        i64 => deserialize_i64,
+        f32 => deserialize_f32,
+        f64 => deserialize_f64,
+    }
+}
+
+struct ValueEnumAccess<'de>(Cow<'de, str>);
+
+impl<'de> de::EnumAccess<'de> for ValueEnumAccess<'de> {
+    type Error = Error;
+    type Variant = UnitOnlyVariantAccess;
+
+    fn variant_seed<V>(
+        self,
+        seed: V,
+    ) -> Result<(V::Value, Self::Variant), Self::Error>
+    where
+        V: de::DeserializeSeed<'de>,
+    {
+        let variant = seed.deserialize(self.0.into_deserializer())?;
+        Ok((variant, UnitOnlyVariantAccess))
+    }
+}
+
+struct UnitOnlyVariantAccess;
+
+impl<'de> de::VariantAccess<'de> for UnitOnlyVariantAccess {
+    type Error = Error;
+
+    fn unit_variant(self) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    fn newtype_variant_seed<T>(self, _seed: T) -> Result<T::Value, Self::Error>
+    where
+        T: de::DeserializeSeed<'de>,
+    {
+        Err(Error::custom("expected unit variant"))
+    }
+
+    fn tuple_variant<V>(
+        self,
+        _len: usize,
+        _visitor: V,
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        Err(Error::custom("expected unit variant"))
+    }
+
+    fn struct_variant<V>(
+        self,
+        _fields: &'static [&'static str],
+        _visitor: V,
+    ) -> Result<V::Value, Self::Error>
+    where
+        V: de::Visitor<'de>,
+    {
+        Err(Error::custom("expected unit variant"))
+    }
+}
diff --git a/third_party/rust/serde_urlencoded/src/lib.rs b/third_party/rust/serde_urlencoded/src/lib.rs
new file mode 100644
index 0000000000..b7ccc783f5
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/src/lib.rs
@@ -0,0 +1,12 @@
+//! `x-www-form-urlencoded` meets Serde
+
+#![warn(unused_extern_crates)]
+#![forbid(unsafe_code)]
+
+pub mod de;
+pub mod ser;
+
+#[doc(inline)]
+pub use crate::de::{from_bytes, from_reader, from_str, Deserializer};
+#[doc(inline)]
+pub use crate::ser::{to_string, Serializer};
diff --git a/third_party/rust/serde_urlencoded/src/ser/key.rs b/third_party/rust/serde_urlencoded/src/ser/key.rs
new file mode 100644
index 0000000000..8128a64ebb
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/src/ser/key.rs
@@ -0,0 +1,77 @@
+use crate::ser::part::Sink;
+use crate::ser::Error;
+use serde::Serialize;
+use std::borrow::Cow;
+use std::ops::Deref;
+
+pub enum Key<'key> {
+    Static(&'static str),
+    Dynamic(Cow<'key, str>),
+}
+
+impl<'key> Deref for Key<'key> {
+    type Target = str;
+
+    fn deref(&self) -> &str {
+        match *self {
+            Key::Static(key) => key,
+            Key::Dynamic(ref key) => key,
+        }
+    }
+}
+
+impl<'key> From<Key<'key>> for Cow<'static, str> {
+    fn from(key: Key<'key>) -> Self {
+        match key {
+            Key::Static(key) => key.into(),
+            Key::Dynamic(key) => key.into_owned().into(),
+        }
+    }
+}
+
+pub struct KeySink<End> {
+    end: End,
+}
+
+impl<End, Ok> KeySink<End>
+where
+    End: for<'key> FnOnce(Key<'key>) -> Result<Ok, Error>,
+{
+    pub fn new(end: End) -> Self {
+        KeySink { end }
+    }
+}
+
+impl<End, Ok> Sink for KeySink<End>
+where
+    End: for<'key> FnOnce(Key<'key>) -> Result<Ok, Error>,
+{
+    type Ok = Ok;
+
+    fn serialize_static_str(self, value: &'static str) -> Result<Ok, Error> {
+        (self.end)(Key::Static(value))
+    }
+
+    fn serialize_str(self, value: &str) -> Result<Ok, Error> {
+        (self.end)(Key::Dynamic(value.into()))
+    }
+
+    fn serialize_string(self, value: String) -> Result<Ok, Error> {
+        (self.end)(Key::Dynamic(value.into()))
+    }
+
+    fn serialize_none(self) -> Result<Ok, Error> {
+        Err(self.unsupported())
+    }
+
+    fn serialize_some<T: ?Sized + Serialize>(
+        self,
+        _value: &T,
+    ) -> Result<Ok, Error> {
+        Err(self.unsupported())
+    }
+
+    fn unsupported(self) -> Error {
+        Error::Custom("unsupported key".into())
+    }
+}
diff --git a/third_party/rust/serde_urlencoded/src/ser/mod.rs b/third_party/rust/serde_urlencoded/src/ser/mod.rs
new file mode 100644
index 0000000000..d75b9022b2
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/src/ser/mod.rs
@@ -0,0 +1,555 @@
+//! Serialization support for the `application/x-www-form-urlencoded` format.
+
+mod key;
+mod pair;
+mod part;
+mod value;
+
+use form_urlencoded::Serializer as UrlEncodedSerializer;
+use form_urlencoded::Target as UrlEncodedTarget;
+use serde::ser;
+use std::borrow::Cow;
+use std::error;
+use std::fmt;
+use std::str;
+
+/// Serializes a value into a `application/x-www-form-urlencoded` `String` buffer.
+///
+/// ```
+/// let meal = &[
+///     ("bread", "baguette"),
+///     ("cheese", "comté"),
+///     ("meat", "ham"),
+///     ("fat", "butter"),
+/// ];
+///
+/// assert_eq!(
+///     serde_urlencoded::to_string(meal),
+///     Ok("bread=baguette&cheese=comt%C3%A9&meat=ham&fat=butter".to_owned()));
+/// ```
+pub fn to_string<T: ser::Serialize>(input: T) -> Result<String, Error> {
+    let mut urlencoder = UrlEncodedSerializer::new("".to_owned());
+    input.serialize(Serializer::new(&mut urlencoder))?;
+    Ok(urlencoder.finish())
+}
+
+/// A serializer for the `application/x-www-form-urlencoded` format.
+///
+/// * Supported top-level inputs are structs, maps and sequences of pairs,
+///   with or without a given length.
+///
+/// * Supported keys and values are integers, bytes (if convertible to strings),
+///   unit structs and unit variants.
+///
+/// * Newtype structs defer to their inner values.
+pub struct Serializer<'input, 'output, Target: UrlEncodedTarget> {
+    urlencoder: &'output mut UrlEncodedSerializer<'input, Target>,
+}
+
+impl<'input, 'output, Target: 'output + UrlEncodedTarget>
+    Serializer<'input, 'output, Target>
+{
+    /// Returns a new `Serializer`.
+    pub fn new(
+        urlencoder: &'output mut UrlEncodedSerializer<'input, Target>,
+    ) -> Self {
+        Serializer { urlencoder }
+    }
+}
+
+/// Errors returned during serializing to `application/x-www-form-urlencoded`.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum Error {
+    Custom(Cow<'static, str>),
+    Utf8(str::Utf8Error),
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match *self {
+            Error::Custom(ref msg) => msg.fmt(f),
+            Error::Utf8(ref err) => write!(f, "invalid UTF-8: {}", err),
+        }
+    }
+}
+
+impl error::Error for Error {
+    fn description(&self) -> &str {
+        match *self {
+            Error::Custom(ref msg) => msg,
+            Error::Utf8(ref err) => error::Error::description(err),
+        }
+    }
+
+    /// The lower-level cause of this error, in the case of a `Utf8` error.
+    fn cause(&self) -> Option<&dyn error::Error> {
+        match *self {
+            Error::Custom(_) => None,
+            Error::Utf8(ref err) => Some(err),
+        }
+    }
+
+    /// The lower-level source of this error, in the case of a `Utf8` error.
+    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
+        match *self {
+            Error::Custom(_) => None,
+            Error::Utf8(ref err) => Some(err),
+        }
+    }
+}
+
+impl ser::Error for Error {
+    fn custom<T: fmt::Display>(msg: T) -> Self {
+        Error::Custom(format!("{}", msg).into())
+    }
+}
+
+/// Sequence serializer.
+pub struct SeqSerializer<'input, 'output, Target: UrlEncodedTarget> {
+    urlencoder: &'output mut UrlEncodedSerializer<'input, Target>,
+}
+
+/// Tuple serializer.
+///
+/// Mostly used for arrays.
+pub struct TupleSerializer<'input, 'output, Target: UrlEncodedTarget> {
+    urlencoder: &'output mut UrlEncodedSerializer<'input, Target>,
+}
+
+/// Tuple struct serializer.
+///
+/// Never instantiated, tuple structs are not supported.
+pub struct TupleStructSerializer<'input, 'output, T: UrlEncodedTarget> {
+    inner: ser::Impossible<&'output mut UrlEncodedSerializer<'input, T>, Error>,
+}
+
+/// Tuple variant serializer.
+///
+/// Never instantiated, tuple variants are not supported.
+pub struct TupleVariantSerializer<'input, 'output, T: UrlEncodedTarget> {
+    inner: ser::Impossible<&'output mut UrlEncodedSerializer<'input, T>, Error>,
+}
+
+/// Map serializer.
+pub struct MapSerializer<'input, 'output, Target: UrlEncodedTarget> {
+    urlencoder: &'output mut UrlEncodedSerializer<'input, Target>,
+    key: Option<Cow<'static, str>>,
+}
+
+/// Struct serializer.
+pub struct StructSerializer<'input, 'output, Target: UrlEncodedTarget> {
+    urlencoder: &'output mut UrlEncodedSerializer<'input, Target>,
+}
+
+/// Struct variant serializer.
+///
+/// Never instantiated, struct variants are not supported.
+pub struct StructVariantSerializer<'input, 'output, T: UrlEncodedTarget> {
+    inner: ser::Impossible<&'output mut UrlEncodedSerializer<'input, T>, Error>,
+}
+
+impl<'input, 'output, Target> ser::Serializer
+    for Serializer<'input, 'output, Target>
+where
+    Target: 'output + UrlEncodedTarget,
+{
+    type Ok = &'output mut UrlEncodedSerializer<'input, Target>;
+    type Error = Error;
+    type SerializeSeq = SeqSerializer<'input, 'output, Target>;
+    type SerializeTuple = TupleSerializer<'input, 'output, Target>;
+    type SerializeTupleStruct = TupleStructSerializer<'input, 'output, Target>;
+    type SerializeTupleVariant =
+        TupleVariantSerializer<'input, 'output, Target>;
+    type SerializeMap = MapSerializer<'input, 'output, Target>;
+    type SerializeStruct = StructSerializer<'input, 'output, Target>;
+    type SerializeStructVariant =
+        StructVariantSerializer<'input, 'output, Target>;
+
+    /// Returns an error.
+    fn serialize_bool(self, _v: bool) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_i8(self, _v: i8) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_i16(self, _v: i16) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_i32(self, _v: i32) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_i64(self, _v: i64) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_u8(self, _v: u8) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_u16(self, _v: u16) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_u32(self, _v: u32) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_u64(self, _v: u64) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_f32(self, _v: f32) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_f64(self, _v: f64) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_char(self, _v: char) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_str(self, _value: &str) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_bytes(self, _value: &[u8]) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns `Ok`.
+    fn serialize_unit(self) -> Result<Self::Ok, Error> {
+        Ok(self.urlencoder)
+    }
+
+    /// Returns `Ok`.
+    fn serialize_unit_struct(
+        self,
+        _name: &'static str,
+    ) -> Result<Self::Ok, Error> {
+        Ok(self.urlencoder)
+    }
+
+    /// Returns an error.
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+    ) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Serializes the inner value, ignoring the newtype name.
+    fn serialize_newtype_struct<T: ?Sized + ser::Serialize>(
+        self,
+        _name: &'static str,
+        value: &T,
+    ) -> Result<Self::Ok, Error> {
+        value.serialize(self)
+    }
+
+    /// Returns an error.
+    fn serialize_newtype_variant<T: ?Sized + ser::Serialize>(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _value: &T,
+    ) -> Result<Self::Ok, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns `Ok`.
+    fn serialize_none(self) -> Result<Self::Ok, Error> {
+        Ok(self.urlencoder)
+    }
+
+    /// Serializes the given value.
+    fn serialize_some<T: ?Sized + ser::Serialize>(
+        self,
+        value: &T,
+    ) -> Result<Self::Ok, Error> {
+        value.serialize(self)
+    }
+
+    /// Serialize a sequence, given length (if any) is ignored.
+    fn serialize_seq(
+        self,
+        _len: Option<usize>,
+    ) -> Result<Self::SerializeSeq, Error> {
+        Ok(SeqSerializer {
+            urlencoder: self.urlencoder,
+        })
+    }
+
+    /// Returns an error.
+    fn serialize_tuple(
+        self,
+        _len: usize,
+    ) -> Result<Self::SerializeTuple, Error> {
+        Ok(TupleSerializer {
+            urlencoder: self.urlencoder,
+        })
+    }
+
+    /// Returns an error.
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleStruct, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Returns an error.
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleVariant, Error> {
+        Err(Error::top_level())
+    }
+
+    /// Serializes a map, given length is ignored.
+    fn serialize_map(
+        self,
+        _len: Option<usize>,
+    ) -> Result<Self::SerializeMap, Error> {
+        Ok(MapSerializer {
+            urlencoder: self.urlencoder,
+            key: None,
+        })
+    }
+
+    /// Serializes a struct, given length is ignored.
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStruct, Error> {
+        Ok(StructSerializer {
+            urlencoder: self.urlencoder,
+        })
+    }
+
+    /// Returns an error.
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStructVariant, Error> {
+        Err(Error::top_level())
+    }
+}
+
+impl<'input, 'output, Target> ser::SerializeSeq
+    for SeqSerializer<'input, 'output, Target>
+where
+    Target: 'output + UrlEncodedTarget,
+{
+    type Ok = &'output mut UrlEncodedSerializer<'input, Target>;
+    type Error = Error;
+
+    fn serialize_element<T: ?Sized + ser::Serialize>(
+        &mut self,
+        value: &T,
+    ) -> Result<(), Error> {
+        value.serialize(pair::PairSerializer::new(self.urlencoder))
+    }
+
+    fn end(self) -> Result<Self::Ok, Error> {
+        Ok(self.urlencoder)
+    }
+}
+
+impl<'input, 'output, Target> ser::SerializeTuple
+    for TupleSerializer<'input, 'output, Target>
+where
+    Target: 'output + UrlEncodedTarget,
+{
+    type Ok = &'output mut UrlEncodedSerializer<'input, Target>;
+    type Error = Error;
+
+    fn serialize_element<T: ?Sized + ser::Serialize>(
+        &mut self,
+        value: &T,
+    ) -> Result<(), Error> {
+        value.serialize(pair::PairSerializer::new(self.urlencoder))
+    }
+
+    fn end(self) -> Result<Self::Ok, Error> {
+        Ok(self.urlencoder)
+    }
+}
+
+impl<'input, 'output, Target> ser::SerializeTupleStruct
+    for TupleStructSerializer<'input, 'output, Target>
+where
+    Target: 'output + UrlEncodedTarget,
+{
+    type Ok = &'output mut UrlEncodedSerializer<'input, Target>;
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized + ser::Serialize>(
+        &mut self,
+        value: &T,
+    ) -> Result<(), Error> {
+        self.inner.serialize_field(value)
+    }
+
+    fn end(self) -> Result<Self::Ok, Error> {
+        self.inner.end()
+    }
+}
+
+impl<'input, 'output, Target> ser::SerializeTupleVariant
+    for TupleVariantSerializer<'input, 'output, Target>
+where
+    Target: 'output + UrlEncodedTarget,
+{
+    type Ok = &'output mut UrlEncodedSerializer<'input, Target>;
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized + ser::Serialize>(
+        &mut self,
+        value: &T,
+    ) -> Result<(), Error> {
+        self.inner.serialize_field(value)
+    }
+
+    fn end(self) -> Result<Self::Ok, Error> {
+        self.inner.end()
+    }
+}
+
+impl<'input, 'output, Target> ser::SerializeMap
+    for MapSerializer<'input, 'output, Target>
+where
+    Target: 'output + UrlEncodedTarget,
+{
+    type Ok = &'output mut UrlEncodedSerializer<'input, Target>;
+    type Error = Error;
+
+    fn serialize_entry<
+        K: ?Sized + ser::Serialize,
+        V: ?Sized + ser::Serialize,
+    >(
+        &mut self,
+        key: &K,
+        value: &V,
+    ) -> Result<(), Error> {
+        let key_sink = key::KeySink::new(|key| {
+            let value_sink = value::ValueSink::new(self.urlencoder, &key);
+            value.serialize(part::PartSerializer::new(value_sink))?;
+            self.key = None;
+            Ok(())
+        });
+        let entry_serializer = part::PartSerializer::new(key_sink);
+        key.serialize(entry_serializer)
+    }
+
+    fn serialize_key<T: ?Sized + ser::Serialize>(
+        &mut self,
+        key: &T,
+    ) -> Result<(), Error> {
+        let key_sink = key::KeySink::new(|key| Ok(key.into()));
+        let key_serializer = part::PartSerializer::new(key_sink);
+        self.key = Some(key.serialize(key_serializer)?);
+        Ok(())
+    }
+
+    fn serialize_value<T: ?Sized + ser::Serialize>(
+        &mut self,
+        value: &T,
+    ) -> Result<(), Error> {
+        {
+            let key = self.key.as_ref().ok_or_else(Error::no_key)?;
+            let value_sink = value::ValueSink::new(self.urlencoder, &key);
+            value.serialize(part::PartSerializer::new(value_sink))?;
+        }
+        self.key = None;
+        Ok(())
+    }
+
+    fn end(self) -> Result<Self::Ok, Error> {
+        Ok(self.urlencoder)
+    }
+}
+
+impl<'input, 'output, Target> ser::SerializeStruct
+    for StructSerializer<'input, 'output, Target>
+where
+    Target: 'output + UrlEncodedTarget,
+{
+    type Ok = &'output mut UrlEncodedSerializer<'input, Target>;
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized + ser::Serialize>(
+        &mut self,
+        key: &'static str,
+        value: &T,
+    ) -> Result<(), Error> {
+        let value_sink = value::ValueSink::new(self.urlencoder, key);
+        value.serialize(part::PartSerializer::new(value_sink))
+    }
+
+    fn end(self) -> Result<Self::Ok, Error> {
+        Ok(self.urlencoder)
+    }
+}
+
+impl<'input, 'output, Target> ser::SerializeStructVariant
+    for StructVariantSerializer<'input, 'output, Target>
+where
+    Target: 'output + UrlEncodedTarget,
+{
+    type Ok = &'output mut UrlEncodedSerializer<'input, Target>;
+    type Error = Error;
+
+    fn serialize_field<T: ?Sized + ser::Serialize>(
+        &mut self,
+        key: &'static str,
+        value: &T,
+    ) -> Result<(), Error> {
+        self.inner.serialize_field(key, value)
+    }
+
+    fn end(self) -> Result<Self::Ok, Error> {
+        self.inner.end()
+    }
+}
+
+impl Error {
+    fn top_level() -> Self {
+        let msg = "top-level serializer supports only maps and structs";
+        Error::Custom(msg.into())
+    }
+
+    fn no_key() -> Self {
+        let msg = "tried to serialize a value before serializing key";
+        Error::Custom(msg.into())
+    }
+}
diff --git a/third_party/rust/serde_urlencoded/src/ser/pair.rs b/third_party/rust/serde_urlencoded/src/ser/pair.rs
new file mode 100644
index 0000000000..429ce4b2bd
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/src/ser/pair.rs
@@ -0,0 +1,271 @@
+use crate::ser::key::KeySink;
+use crate::ser::part::PartSerializer;
+use crate::ser::value::ValueSink;
+use crate::ser::Error;
+use form_urlencoded::Serializer as UrlEncodedSerializer;
+use form_urlencoded::Target as UrlEncodedTarget;
+use serde::ser;
+use std::borrow::Cow;
+use std::mem;
+
+pub struct PairSerializer<'input, 'target, Target: UrlEncodedTarget> {
+    urlencoder: &'target mut UrlEncodedSerializer<'input, Target>,
+    state: PairState,
+}
+
+impl<'input, 'target, Target> PairSerializer<'input, 'target, Target>
+where
+    Target: 'target + UrlEncodedTarget,
+{
+    pub fn new(
+        urlencoder: &'target mut UrlEncodedSerializer<'input, Target>,
+    ) -> Self {
+        PairSerializer {
+            urlencoder,
+            state: PairState::WaitingForKey,
+        }
+    }
+}
+
+impl<'input, 'target, Target> ser::Serializer
+    for PairSerializer<'input, 'target, Target>
+where
+    Target: 'target + UrlEncodedTarget,
+{
+    type Ok = ();
+    type Error = Error;
+    type SerializeSeq = ser::Impossible<(), Error>;
+    type SerializeTuple = Self;
+    type SerializeTupleStruct = ser::Impossible<(), Error>;
+    type SerializeTupleVariant = ser::Impossible<(), Error>;
+    type SerializeMap = ser::Impossible<(), Error>;
+    type SerializeStruct = ser::Impossible<(), Error>;
+    type SerializeStructVariant = ser::Impossible<(), Error>;
+
+    fn serialize_bool(self, _v: bool) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_i8(self, _v: i8) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_i16(self, _v: i16) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_i32(self, _v: i32) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_i64(self, _v: i64) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_u8(self, _v: u8) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_u16(self, _v: u16) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_u32(self, _v: u32) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_u64(self, _v: u64) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_f32(self, _v: f32) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_f64(self, _v: f64) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_char(self, _v: char) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_str(self, _value: &str) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_bytes(self, _value: &[u8]) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_unit(self) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_unit_struct(self, _name: &'static str) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+    ) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_newtype_struct<T: ?Sized + ser::Serialize>(
+        self,
+        _name: &'static str,
+        value: &T,
+    ) -> Result<(), Error> {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized + ser::Serialize>(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _value: &T,
+    ) -> Result<(), Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_none(self) -> Result<(), Error> {
+        Ok(())
+    }
+
+    fn serialize_some<T: ?Sized + ser::Serialize>(
+        self,
+        value: &T,
+    ) -> Result<(), Error> {
+        value.serialize(self)
+    }
+
+    fn serialize_seq(
+        self,
+        _len: Option<usize>,
+    ) -> Result<Self::SerializeSeq, Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_tuple(self, len: usize) -> Result<Self, Error> {
+        if len == 2 {
+            Ok(self)
+        } else {
+            Err(Error::unsupported_pair())
+        }
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleStruct, Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleVariant, Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_map(
+        self,
+        _len: Option<usize>,
+    ) -> Result<Self::SerializeMap, Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStruct, Error> {
+        Err(Error::unsupported_pair())
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStructVariant, Error> {
+        Err(Error::unsupported_pair())
+    }
+}
+
+impl<'input, 'target, Target> ser::SerializeTuple
+    for PairSerializer<'input, 'target, Target>
+where
+    Target: 'target + UrlEncodedTarget,
+{
+    type Ok = ();
+    type Error = Error;
+
+    fn serialize_element<T: ?Sized + ser::Serialize>(
+        &mut self,
+        value: &T,
+    ) -> Result<(), Error> {
+        match mem::replace(&mut self.state, PairState::Done) {
+            PairState::WaitingForKey => {
+                let key_sink = KeySink::new(|key| Ok(key.into()));
+                let key_serializer = PartSerializer::new(key_sink);
+                self.state = PairState::WaitingForValue {
+                    key: value.serialize(key_serializer)?,
+                };
+                Ok(())
+            }
+            PairState::WaitingForValue { key } => {
+                let result = {
+                    let value_sink = ValueSink::new(self.urlencoder, &key);
+                    let value_serializer = PartSerializer::new(value_sink);
+                    value.serialize(value_serializer)
+                };
+                if result.is_ok() {
+                    self.state = PairState::Done;
+                } else {
+                    self.state = PairState::WaitingForValue { key };
+                }
+                result
+            }
+            PairState::Done => Err(Error::done()),
+        }
+    }
+
+    fn end(self) -> Result<(), Error> {
+        if let PairState::Done = self.state {
+            Ok(())
+        } else {
+            Err(Error::not_done())
+        }
+    }
+}
+
+enum PairState {
+    WaitingForKey,
+    WaitingForValue { key: Cow<'static, str> },
+    Done,
+}
+
+impl Error {
+    fn done() -> Self {
+        Error::Custom("this pair has already been serialized".into())
+    }
+
+    fn not_done() -> Self {
+        Error::Custom("this pair has not yet been serialized".into())
+    }
+
+    fn unsupported_pair() -> Self {
+        Error::Custom("unsupported pair".into())
+    }
+}
diff --git a/third_party/rust/serde_urlencoded/src/ser/part.rs b/third_party/rust/serde_urlencoded/src/ser/part.rs
new file mode 100644
index 0000000000..1deffa54b5
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/src/ser/part.rs
@@ -0,0 +1,236 @@
+use crate::ser::Error;
+use serde::ser;
+use std::str;
+
+pub struct PartSerializer<S> {
+    sink: S,
+}
+
+impl<S: Sink> PartSerializer<S> {
+    pub fn new(sink: S) -> Self {
+        PartSerializer { sink }
+    }
+}
+
+pub trait Sink: Sized {
+    type Ok;
+
+    fn serialize_static_str(
+        self,
+        value: &'static str,
+    ) -> Result<Self::Ok, Error>;
+
+    fn serialize_str(self, value: &str) -> Result<Self::Ok, Error>;
+    fn serialize_string(self, value: String) -> Result<Self::Ok, Error>;
+    fn serialize_none(self) -> Result<Self::Ok, Error>;
+
+    fn serialize_some<T: ?Sized + ser::Serialize>(
+        self,
+        value: &T,
+    ) -> Result<Self::Ok, Error>;
+
+    fn unsupported(self) -> Error;
+}
+
+impl<S: Sink> ser::Serializer for PartSerializer<S> {
+    type Ok = S::Ok;
+    type Error = Error;
+    type SerializeSeq = ser::Impossible<S::Ok, Error>;
+    type SerializeTuple = ser::Impossible<S::Ok, Error>;
+    type SerializeTupleStruct = ser::Impossible<S::Ok, Error>;
+    type SerializeTupleVariant = ser::Impossible<S::Ok, Error>;
+    type SerializeMap = ser::Impossible<S::Ok, Error>;
+    type SerializeStruct = ser::Impossible<S::Ok, Error>;
+    type SerializeStructVariant = ser::Impossible<S::Ok, Error>;
+
+    fn serialize_bool(self, v: bool) -> Result<S::Ok, Error> {
+        self.sink
+            .serialize_static_str(if v { "true" } else { "false" })
+    }
+
+    fn serialize_i8(self, v: i8) -> Result<S::Ok, Error> {
+        self.serialize_integer(v)
+    }
+
+    fn serialize_i16(self, v: i16) -> Result<S::Ok, Error> {
+        self.serialize_integer(v)
+    }
+
+    fn serialize_i32(self, v: i32) -> Result<S::Ok, Error> {
+        self.serialize_integer(v)
+    }
+
+    fn serialize_i64(self, v: i64) -> Result<S::Ok, Error> {
+        self.serialize_integer(v)
+    }
+
+    fn serialize_u8(self, v: u8) -> Result<S::Ok, Error> {
+        self.serialize_integer(v)
+    }
+
+    fn serialize_u16(self, v: u16) -> Result<S::Ok, Error> {
+        self.serialize_integer(v)
+    }
+
+    fn serialize_u32(self, v: u32) -> Result<S::Ok, Error> {
+        self.serialize_integer(v)
+    }
+
+    fn serialize_u64(self, v: u64) -> Result<S::Ok, Error> {
+        self.serialize_integer(v)
+    }
+
+    fn serialize_u128(self, v: u128) -> Result<S::Ok, Error> {
+        self.serialize_integer(v)
+    }
+
+    fn serialize_i128(self, v: i128) -> Result<S::Ok, Error> {
+        self.serialize_integer(v)
+    }
+
+    fn serialize_f32(self, v: f32) -> Result<S::Ok, Error> {
+        self.serialize_floating(v)
+    }
+
+    fn serialize_f64(self, v: f64) -> Result<S::Ok, Error> {
+        self.serialize_floating(v)
+    }
+
+    fn serialize_char(self, v: char) -> Result<S::Ok, Error> {
+        self.sink.serialize_string(v.to_string())
+    }
+
+    fn serialize_str(self, value: &str) -> Result<S::Ok, Error> {
+        self.sink.serialize_str(value)
+    }
+
+    fn serialize_bytes(self, value: &[u8]) -> Result<S::Ok, Error> {
+        match str::from_utf8(value) {
+            Ok(value) => self.sink.serialize_str(value),
+            Err(err) => Err(Error::Utf8(err)),
+        }
+    }
+
+    fn serialize_unit(self) -> Result<S::Ok, Error> {
+        Err(self.sink.unsupported())
+    }
+
+    fn serialize_unit_struct(self, name: &'static str) -> Result<S::Ok, Error> {
+        self.sink.serialize_static_str(name)
+    }
+
+    fn serialize_unit_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        variant: &'static str,
+    ) -> Result<S::Ok, Error> {
+        self.sink.serialize_static_str(variant)
+    }
+
+    fn serialize_newtype_struct<T: ?Sized + ser::Serialize>(
+        self,
+        _name: &'static str,
+        value: &T,
+    ) -> Result<S::Ok, Error> {
+        value.serialize(self)
+    }
+
+    fn serialize_newtype_variant<T: ?Sized + ser::Serialize>(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _value: &T,
+    ) -> Result<S::Ok, Error> {
+        Err(self.sink.unsupported())
+    }
+
+    fn serialize_none(self) -> Result<S::Ok, Error> {
+        self.sink.serialize_none()
+    }
+
+    fn serialize_some<T: ?Sized + ser::Serialize>(
+        self,
+        value: &T,
+    ) -> Result<S::Ok, Error> {
+        self.sink.serialize_some(value)
+    }
+
+    fn serialize_seq(
+        self,
+        _len: Option<usize>,
+    ) -> Result<Self::SerializeSeq, Error> {
+        Err(self.sink.unsupported())
+    }
+
+    fn serialize_tuple(
+        self,
+        _len: usize,
+    ) -> Result<Self::SerializeTuple, Error> {
+        Err(self.sink.unsupported())
+    }
+
+    fn serialize_tuple_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTuple, Error> {
+        Err(self.sink.unsupported())
+    }
+
+    fn serialize_tuple_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeTupleVariant, Error> {
+        Err(self.sink.unsupported())
+    }
+
+    fn serialize_map(
+        self,
+        _len: Option<usize>,
+    ) -> Result<Self::SerializeMap, Error> {
+        Err(self.sink.unsupported())
+    }
+
+    fn serialize_struct(
+        self,
+        _name: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStruct, Error> {
+        Err(self.sink.unsupported())
+    }
+
+    fn serialize_struct_variant(
+        self,
+        _name: &'static str,
+        _variant_index: u32,
+        _variant: &'static str,
+        _len: usize,
+    ) -> Result<Self::SerializeStructVariant, Error> {
+        Err(self.sink.unsupported())
+    }
+}
+
+impl<S: Sink> PartSerializer<S> {
+    fn serialize_integer<I>(self, value: I) -> Result<S::Ok, Error>
+    where
+        I: itoa::Integer,
+    {
+        let mut buf = itoa::Buffer::new();
+        let part = buf.format(value);
+        ser::Serializer::serialize_str(self, part)
+    }
+
+    fn serialize_floating<F>(self, value: F) -> Result<S::Ok, Error>
+    where
+        F: ryu::Float,
+    {
+        let mut buf = ryu::Buffer::new();
+        let part = buf.format(value);
+        ser::Serializer::serialize_str(self, part)
+    }
+}
diff --git a/third_party/rust/serde_urlencoded/src/ser/value.rs b/third_party/rust/serde_urlencoded/src/ser/value.rs
new file mode 100644
index 0000000000..e8823ce703
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/src/ser/value.rs
@@ -0,0 +1,62 @@
+use crate::ser::part::{PartSerializer, Sink};
+use crate::ser::Error;
+use form_urlencoded::Serializer as UrlEncodedSerializer;
+use form_urlencoded::Target as UrlEncodedTarget;
+use serde::ser::Serialize;
+use std::str;
+
+pub struct ValueSink<'input, 'key, 'target, Target>
+where
+    Target: UrlEncodedTarget,
+{
+    urlencoder: &'target mut UrlEncodedSerializer<'input, Target>,
+    key: &'key str,
+}
+
+impl<'input, 'key, 'target, Target> ValueSink<'input, 'key, 'target, Target>
+where
+    Target: 'target + UrlEncodedTarget,
+{
+    pub fn new(
+        urlencoder: &'target mut UrlEncodedSerializer<'input, Target>,
+        key: &'key str,
+    ) -> Self {
+        ValueSink { urlencoder, key }
+    }
+}
+
+impl<'input, 'key, 'target, Target> Sink
+    for ValueSink<'input, 'key, 'target, Target>
+where
+    Target: 'target + UrlEncodedTarget,
+{
+    type Ok = ();
+
+    fn serialize_str(self, value: &str) -> Result<(), Error> {
+        self.urlencoder.append_pair(self.key, value);
+        Ok(())
+    }
+
+    fn serialize_static_str(self, value: &'static str) -> Result<(), Error> {
+        self.serialize_str(value)
+    }
+
+    fn serialize_string(self, value: String) -> Result<(), Error> {
+        self.serialize_str(&value)
+    }
+
+    fn serialize_none(self) -> Result<Self::Ok, Error> {
+        Ok(())
+    }
+
+    fn serialize_some<T: ?Sized + Serialize>(
+        self,
+        value: &T,
+    ) -> Result<Self::Ok, Error> {
+        value.serialize(PartSerializer::new(self))
+    }
+
+    fn unsupported(self) -> Error {
+        Error::Custom("unsupported value".into())
+    }
+}
diff --git a/third_party/rust/serde_urlencoded/tests/test_deserialize.rs b/third_party/rust/serde_urlencoded/tests/test_deserialize.rs
new file mode 100644
index 0000000000..00700d3060
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/tests/test_deserialize.rs
@@ -0,0 +1,88 @@
+use serde_derive::Deserialize;
+
+#[derive(Deserialize, Debug, PartialEq)]
+struct NewType<T>(T);
+
+#[test]
+fn deserialize_newtype_i32() {
+    let result = vec![("field".to_owned(), NewType(11))];
+
+    assert_eq!(serde_urlencoded::from_str("field=11"), Ok(result));
+}
+
+#[test]
+fn deserialize_bytes() {
+    let result = vec![("first".to_owned(), 23), ("last".to_owned(), 42)];
+
+    assert_eq!(
+        serde_urlencoded::from_bytes(b"first=23&last=42"),
+        Ok(result)
+    );
+}
+
+#[test]
+fn deserialize_str() {
+    let result = vec![("first".to_owned(), 23), ("last".to_owned(), 42)];
+
+    assert_eq!(serde_urlencoded::from_str("first=23&last=42"), Ok(result));
+}
+
+#[test]
+fn deserialize_borrowed_str() {
+    let result = vec![("first", 23), ("last", 42)];
+
+    assert_eq!(serde_urlencoded::from_str("first=23&last=42"), Ok(result));
+}
+
+#[test]
+fn deserialize_reader() {
+    let result = vec![("first".to_owned(), 23), ("last".to_owned(), 42)];
+
+    assert_eq!(
+        serde_urlencoded::from_reader(b"first=23&last=42" as &[_]),
+        Ok(result)
+    );
+}
+
+#[test]
+fn deserialize_option() {
+    let result = vec![
+        ("first".to_owned(), Some(23)),
+        ("last".to_owned(), Some(42)),
+    ];
+    assert_eq!(serde_urlencoded::from_str("first=23&last=42"), Ok(result));
+}
+
+#[test]
+fn deserialize_unit() {
+    assert_eq!(serde_urlencoded::from_str(""), Ok(()));
+    assert_eq!(serde_urlencoded::from_str("&"), Ok(()));
+    assert_eq!(serde_urlencoded::from_str("&&"), Ok(()));
+    assert!(serde_urlencoded::from_str::<()>("first=23").is_err());
+}
+
+#[derive(Deserialize, Debug, PartialEq, Eq)]
+enum X {
+    A,
+    B,
+    C,
+}
+
+#[test]
+fn deserialize_unit_enum() {
+    let result = vec![
+        ("one".to_owned(), X::A),
+        ("two".to_owned(), X::B),
+        ("three".to_owned(), X::C),
+    ];
+
+    assert_eq!(
+        serde_urlencoded::from_str("one=A&two=B&three=C"),
+        Ok(result)
+    );
+}
+
+#[test]
+fn deserialize_unit_type() {
+    assert_eq!(serde_urlencoded::from_str(""), Ok(()));
+}
diff --git a/third_party/rust/serde_urlencoded/tests/test_serialize.rs b/third_party/rust/serde_urlencoded/tests/test_serialize.rs
new file mode 100644
index 0000000000..abb4907a46
--- /dev/null
+++ b/third_party/rust/serde_urlencoded/tests/test_serialize.rs
@@ -0,0 +1,104 @@
+use serde_derive::Serialize;
+
+#[derive(Serialize)]
+struct NewType<T>(T);
+
+#[test]
+fn serialize_newtype_i32() {
+    let params = &[("field", Some(NewType(11)))];
+    assert_eq!(
+        serde_urlencoded::to_string(params),
+        Ok("field=11".to_owned())
+    );
+}
+
+#[test]
+fn serialize_newtype_u128() {
+    let params = &[("field", Some(NewType(u128::MAX)))];
+    assert_eq!(
+        serde_urlencoded::to_string(params),
+        Ok(format!("field={}", u128::MAX))
+    );
+}
+
+#[test]
+fn serialize_newtype_i128() {
+    let params = &[("field", Some(NewType(i128::MIN)))];
+    assert_eq!(
+        serde_urlencoded::to_string(params),
+        Ok(format!("field={}", i128::MIN))
+    );
+}
+
+#[test]
+fn serialize_option_map_int() {
+    let params = &[("first", Some(23)), ("middle", None), ("last", Some(42))];
+
+    assert_eq!(
+        serde_urlencoded::to_string(params),
+        Ok("first=23&last=42".to_owned())
+    );
+}
+
+#[test]
+fn serialize_option_map_string() {
+    let params = &[
+        ("first", Some("hello")),
+        ("middle", None),
+        ("last", Some("world")),
+    ];
+
+    assert_eq!(
+        serde_urlencoded::to_string(params),
+        Ok("first=hello&last=world".to_owned())
+    );
+}
+
+#[test]
+fn serialize_option_map_bool() {
+    let params = &[("one", Some(true)), ("two", Some(false))];
+
+    assert_eq!(
+        serde_urlencoded::to_string(params),
+        Ok("one=true&two=false".to_owned())
+    );
+}
+
+#[test]
+fn serialize_map_bool() {
+    let params = &[("one", true), ("two", false)];
+
+    assert_eq!(
+        serde_urlencoded::to_string(params),
+        Ok("one=true&two=false".to_owned())
+    );
+}
+
+#[derive(Serialize)]
+enum X {
+    A,
+    B,
+    C,
+}
+
+#[test]
+fn serialize_unit_enum() {
+    let params = &[("one", X::A), ("two", X::B), ("three", X::C)];
+    assert_eq!(
+        serde_urlencoded::to_string(params),
+        Ok("one=A&two=B&three=C".to_owned())
+    );
+}
+
+#[derive(Serialize)]
+struct Unit;
+
+#[test]
+fn serialize_unit_struct() {
+    assert_eq!(serde_urlencoded::to_string(Unit), Ok("".to_owned()));
+}
+
+#[test]
+fn serialize_unit_type() {
+    assert_eq!(serde_urlencoded::to_string(()), Ok("".to_owned()));
+}