mozilla-bmo1757571.patch
branchfirefox98
changeset 1172 7bdeb580be51
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mozilla-bmo1757571.patch	Mon Apr 04 10:22:27 2022 +0200
@@ -0,0 +1,1082 @@
+diff --git a/Cargo.lock b/Cargo.lock
+--- a/Cargo.lock
++++ b/Cargo.lock
+@@ -972,13 +972,13 @@
+  "cfg-if 1.0.0",
+ ]
+ 
+ [[package]]
+ name = "crossbeam-channel"
+-version = "0.5.2"
+-source = "registry+https://github.com/rust-lang/crates.io-index"
+-checksum = "e54ea8bc3fb1ee042f5aace6e3c6e025d3874866da222930f70ce62aceba0bfa"
++version = "0.5.4"
++source = "registry+https://github.com/rust-lang/crates.io-index"
++checksum = "5aaa7bd5fb665c6864b5f963dd9097905c54125909c7aa94c9e18507cdbe6c53"
+ dependencies = [
+  "cfg-if 1.0.0",
+  "crossbeam-utils 0.8.6",
+ ]
+ 
+diff --git a/third_party/rust/crossbeam-channel/.cargo-checksum.json b/third_party/rust/crossbeam-channel/.cargo-checksum.json
+--- a/third_party/rust/crossbeam-channel/.cargo-checksum.json
++++ b/third_party/rust/crossbeam-channel/.cargo-checksum.json
+@@ -1 +1 @@
+-{"files":{"CHANGELOG.md":"e70d1a5fa6697a8b24e193e3934975317df12279c167b90fcb9616291792197c","Cargo.lock":"0f4e59f28bdd52c4781d102fc7d1f16d1ea417aaec0a4846432444a4019b2537","Cargo.toml":"c8334f658b699a1a0e25d997d752a9493a627f9ddcb7aab739c7319ea583882f","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"5734ed989dfca1f625b40281ee9f4530f91b2411ec01cb748223e7eb87e201ab","LICENSE-THIRD-PARTY":"b16db96b93b1d7cf7bea533f572091ec6bca3234fbe0a83038be772ff391a44c","README.md":"415a71d4978cfd338a6ae1f1b41284652eccd277a815542c304647dc437a8274","benches/crossbeam.rs":"96cb1abd23cac3ef8a7174a802e94609926b555bb02c9658c78723d433f1dd92","examples/fibonacci.rs":"4e88fa40048cdc31e9c7bb60347d46f92543d7ddf39cab3b52bfe44affdb6a02","examples/matching.rs":"63c250e164607a7a9f643d46f107bb5da846d49e89cf9069909562d20e530f71","examples/stopwatch.rs":"d02121258f08d56f1eb7997e19bcb9bacb6836cfa0abbba90a9e59d8a50ae5cf","src/channel.rs":"a9baaad2f414c38cd324a60ac9375ca58462ce6662217683648e9b66cec43a8c","src/context.rs":"ff4d39639ddf16aaab582d4a5f3d10ef2c71afe1abbf4e60f3d9d2ddbd72c230","src/counter.rs":"c49a9f44587888850edeb62f7c8ecd1acecb39c836834254ff3ac934c478440a","src/err.rs":"fdbde7279a1e74973e5c7d3e835a97836229a357fe465c0ba1a37f2a012d1bef","src/flavors/array.rs":"853c2ad068f912cfb49877bcd41e241f34b25026b709bf0629523f19952e3adc","src/flavors/at.rs":"65bf870b3ddb14738256706b0276f2656ad1fe9cd8eb91737489868edd088e92","src/flavors/list.rs":"50dbe59616c39b5aa184470023ce0cfb1cb0dbd92e1577375d299446981527c0","src/flavors/mod.rs":"3d9d43bc38b0adb18c96c995c2bd3421d8e33ab6c30b20c3c467d21d48e485dc","src/flavors/never.rs":"0e7921922d00c711552fb063c63c78192fa6ddc0762fb81c1713b847495ec39a","src/flavors/tick.rs":"38a479b9f4a72a5ccb9c407a1e7b44d36b6ad0f4e214e39266b12b9564c803dc","src/flavors/zero.rs":"012a53f56b86df22ce49866da95e5f457fb99a18a098f0f64779c6d1cdd7092f","src/lib.rs":"3a65706d4124844ffc4c8cb1f8cc779631ec94f449f85cbb68364ad3619404f1","src/select.rs":"66eb10a6cbdf8dd0869f2a7cac9992fdaee36c9e2a01d708d39d7c794572935b","src/select_macro.rs":"96bc9acb9a22588a4e733b0ab0761ad2be9a6b3e03744e8fc9c6de9ae433b696","src/utils.rs":"746fe315d6cfc832e3dda35e5055c0fd5c99907f1303b2ea7eacc4e37c8527e1","src/waker.rs":"591ee70bf62ccad5aa2fac7b92d444183b02790a79c024f016c78de2396d08a3","tests/after.rs":"0154a8e152880db17a20514ecdd49dabc361d3629858d119b9746b5e932c780c","tests/array.rs":"e5f25e8991863a9a86d61a66be646d04feae527f35b1697fd215b97af4383736","tests/golang.rs":"dc85669c9c4e902b1bb263d00f5cb6f9ecb6d42b19fe53425b55ce97c887da49","tests/iter.rs":"25dc02135bbae9d47a30f9047661648e66bdc134e40ba78bc2fbacbb8b3819bc","tests/list.rs":"de865ef097f3bcb35c1c814554e6108fed43b3dbb1533c8bbcf8688cceb6b6ab","tests/mpsc.rs":"401aa3c6923815058881ddce98070df68ebab283913c89c007436bb8af7ca0ea","tests/never.rs":"ee40c4fc4dd5af4983fae8de6927f52b81174d222c162f745b26c4a6c7108e4f","tests/ready.rs":"d349702f123925a0781b48d677e6dcf64fc5d1fc788a7bf1e151a3d57e81871c","tests/same_channel.rs":"2bab761443671e841e1b2476bd8082d75533a2f6be7946f5dbcee67cdc82dccb","tests/select.rs":"d20259a45f387cbce80c2c876ae81ea3883f36ea01c5151c159d58c362f6ba07","tests/select_macro.rs":"d3af2dc98e0dd03dc4ffab464b8ccb2f8b7504e8bb830948a04c015b92f0b296","tests/thread_locals.rs":"a1ce59e2aff69161621c0cb215eb6ea238088c06a31a8507a74cf179fd5a4299","tests/tick.rs":"5f697bd14c48505d932e82065b5302ef668e1cc19cac18e8ac22e0c83c221c1d","tests/zero.rs":"afbd838001d4196daddf17133e60ccea31529cc48ee01e245ac0d6366d1e30b9"},"package":"e54ea8bc3fb1ee042f5aace6e3c6e025d3874866da222930f70ce62aceba0bfa"}
+\ No newline at end of file
++{"files":{"CHANGELOG.md":"0f549e63930d1e576f117ee9249c84276eadbe6fb95818680c042c6c0af8a807","Cargo.lock":"834da9468c17c8e1b7fe457764257f4dfdaa24bc98cbdfedf3af4f3d4f5c1e6a","Cargo.toml":"1296a016c4c23d38a35b3d737ee8285fcaaf7d23b7bbb5a3484cefe56b7ca32a","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"5734ed989dfca1f625b40281ee9f4530f91b2411ec01cb748223e7eb87e201ab","LICENSE-THIRD-PARTY":"b16db96b93b1d7cf7bea533f572091ec6bca3234fbe0a83038be772ff391a44c","README.md":"415a71d4978cfd338a6ae1f1b41284652eccd277a815542c304647dc437a8274","benches/crossbeam.rs":"96cb1abd23cac3ef8a7174a802e94609926b555bb02c9658c78723d433f1dd92","examples/fibonacci.rs":"4e88fa40048cdc31e9c7bb60347d46f92543d7ddf39cab3b52bfe44affdb6a02","examples/matching.rs":"63c250e164607a7a9f643d46f107bb5da846d49e89cf9069909562d20e530f71","examples/stopwatch.rs":"d02121258f08d56f1eb7997e19bcb9bacb6836cfa0abbba90a9e59d8a50ae5cf","src/channel.rs":"3bbf69df6c3f0071a44bab0139a749447604f5ffa5e45acc2998803dee066522","src/context.rs":"ff4d39639ddf16aaab582d4a5f3d10ef2c71afe1abbf4e60f3d9d2ddbd72c230","src/counter.rs":"c49a9f44587888850edeb62f7c8ecd1acecb39c836834254ff3ac934c478440a","src/err.rs":"44cb2024ee6b0cd6fd24996430e53720769f64b4ac35016bc3e05cb9db48681d","src/flavors/array.rs":"0743fb71a8adc8d95143b1cdae996823dddb7ab7fb7139eb6e0cdf733ff231ee","src/flavors/at.rs":"1db64919593b7c14f838c16a22732515f1e716d2d5f6cc639f42631380e545cd","src/flavors/list.rs":"017b66a84ada393d11d1730297426338244b115944a4d631573447641a66bed6","src/flavors/mod.rs":"3d9d43bc38b0adb18c96c995c2bd3421d8e33ab6c30b20c3c467d21d48e485dc","src/flavors/never.rs":"747da857aa1a7601641f23f4930e6ad00ebaf50456d9be5c7aa270e2ecc24dcb","src/flavors/tick.rs":"69b2dfe0186bc8b9fd7a73e32da59d2656d8150da1e00fba92a412e0907568a3","src/flavors/zero.rs":"1edd8e5114daa5b82ec9f4a715c0389a9de02cce64de0f71b4225868dad99a99","src/lib.rs":"3a65706d4124844ffc4c8cb1f8cc779631ec94f449f85cbb68364ad3619404f1","src/select.rs":"63dbfde7098dac1424f1cc884f6b8364f3bf3e06527691dde628ff6c416a7f35","src/select_macro.rs":"582a033cc0a51917fd5197dfb66677e9d7982c013414e75ae78b4a740189a56d","src/utils.rs":"b4d38e39a7d7774729458b1b39253377a55657d377c483d30b32e42a0a0092e3","src/waker.rs":"2114bd84f35b2c654d1914127e0380e17a5c20d8ec1e20449af3d653cad27c64","tests/after.rs":"0154a8e152880db17a20514ecdd49dabc361d3629858d119b9746b5e932c780c","tests/array.rs":"e0f3814328c79727a85df3aee0409701849dabfeaaa2f70721e14396fbaba1cd","tests/golang.rs":"dc85669c9c4e902b1bb263d00f5cb6f9ecb6d42b19fe53425b55ce97c887da49","tests/iter.rs":"25dc02135bbae9d47a30f9047661648e66bdc134e40ba78bc2fbacbb8b3819bc","tests/list.rs":"de865ef097f3bcb35c1c814554e6108fed43b3dbb1533c8bbcf8688cceb6b6ab","tests/mpsc.rs":"401aa3c6923815058881ddce98070df68ebab283913c89c007436bb8af7ca0ea","tests/never.rs":"ee40c4fc4dd5af4983fae8de6927f52b81174d222c162f745b26c4a6c7108e4f","tests/ready.rs":"d349702f123925a0781b48d677e6dcf64fc5d1fc788a7bf1e151a3d57e81871c","tests/same_channel.rs":"2bab761443671e841e1b2476bd8082d75533a2f6be7946f5dbcee67cdc82dccb","tests/select.rs":"d20259a45f387cbce80c2c876ae81ea3883f36ea01c5151c159d58c362f6ba07","tests/select_macro.rs":"948eb21f72a9317c0de98a9bd21f6f8ff2b09b73b45c171c45b04c051a2fd0c4","tests/thread_locals.rs":"a1ce59e2aff69161621c0cb215eb6ea238088c06a31a8507a74cf179fd5a4299","tests/tick.rs":"5f697bd14c48505d932e82065b5302ef668e1cc19cac18e8ac22e0c83c221c1d","tests/zero.rs":"afbd838001d4196daddf17133e60ccea31529cc48ee01e245ac0d6366d1e30b9"},"package":"5aaa7bd5fb665c6864b5f963dd9097905c54125909c7aa94c9e18507cdbe6c53"}
+\ No newline at end of file
+diff --git a/third_party/rust/crossbeam-channel/CHANGELOG.md b/third_party/rust/crossbeam-channel/CHANGELOG.md
+--- a/third_party/rust/crossbeam-channel/CHANGELOG.md
++++ b/third_party/rust/crossbeam-channel/CHANGELOG.md
+@@ -1,8 +1,16 @@
++# Version 0.5.4
++
++- Workaround a bug in upstream related to TLS access on AArch64 Linux. (#802)
++
++# Version 0.5.3
++
++- Fix panic on very large timeout. (#798)
++
+ # Version 0.5.2
+ 
+-- Fix stacked borrows violations. (#763, #764)
++- Fix stacked borrows violations when `-Zmiri-tag-raw-pointers` is enabled. (#763, #764)
+ 
+ # Version 0.5.1
+ 
+ - Fix memory leak in unbounded channel. (#669)
+ 
+@@ -19,10 +27,12 @@
+ 
+ - Fix bug in release (yanking 0.4.3)
+ - Fix UB and breaking change introduced in 0.4.3
+ 
+ # Version 0.4.3
++
++**Note**: This release has been yanked. See [CVE-2020-15254](https://github.com/crossbeam-rs/crossbeam/security/advisories/GHSA-v5m7-53cv-f3hx) for details.
+ 
+ - Change license to "MIT OR Apache-2.0".
+ 
+ # Version 0.4.2
+ 
+diff --git a/third_party/rust/crossbeam-channel/Cargo.lock b/third_party/rust/crossbeam-channel/Cargo.lock
+--- a/third_party/rust/crossbeam-channel/Cargo.lock
++++ b/third_party/rust/crossbeam-channel/Cargo.lock
+@@ -8,34 +8,34 @@
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+ 
+ [[package]]
+ name = "crossbeam-channel"
+-version = "0.5.2"
++version = "0.5.4"
+ dependencies = [
+  "cfg-if",
+  "crossbeam-utils",
+  "num_cpus",
+  "rand",
+  "signal-hook",
+ ]
+ 
+ [[package]]
+ name = "crossbeam-utils"
+-version = "0.8.6"
++version = "0.8.8"
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+-checksum = "cfcae03edb34f947e64acdb1c33ec169824e20657e9ecb61cef6c8c74dcb8120"
++checksum = "0bf124c720b7686e3c2663cf54062ab0f68a88af2fb6a030e87e30bf721fcb38"
+ dependencies = [
+  "cfg-if",
+  "lazy_static",
+ ]
+ 
+ [[package]]
+ name = "getrandom"
+-version = "0.2.3"
++version = "0.2.5"
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+-checksum = "7fcd999463524c52659517fe2cea98493cfe485d10565e7b0fb07dbba7ad2753"
++checksum = "d39cd93900197114fa1fcb7ae84ca742095eed9442088988ae74fa744e930e77"
+ dependencies = [
+  "cfg-if",
+  "libc",
+  "wasi",
+ ]
+@@ -55,13 +55,13 @@
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+ 
+ [[package]]
+ name = "libc"
+-version = "0.2.112"
++version = "0.2.120"
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+-checksum = "1b03d17f364a3a042d5e5d46b053bbbf82c92c9430c592dd4c064dc6ee997125"
++checksum = "ad5c14e80759d0939d013e6ca49930e59fc53dd8e5009132f76240c179380c09"
+ 
+ [[package]]
+ name = "num_cpus"
+ version = "1.13.1"
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+@@ -77,18 +77,17 @@
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+ checksum = "eb9f9e6e233e5c4a35559a617bf40a4ec447db2e84c20b55a6f83167b7e57872"
+ 
+ [[package]]
+ name = "rand"
+-version = "0.8.4"
++version = "0.8.5"
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+-checksum = "2e7573632e6454cf6b99d7aac4ccca54be06da05aca2ef7423d22d27d4d4bcd8"
++checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+ dependencies = [
+  "libc",
+  "rand_chacha",
+  "rand_core",
+- "rand_hc",
+ ]
+ 
+ [[package]]
+ name = "rand_chacha"
+ version = "0.3.1"
+@@ -104,19 +103,10 @@
+ version = "0.6.3"
+ source = "registry+https://github.com/rust-lang/crates.io-index"
+ checksum = "d34f1408f55294453790c48b2f1ebbb1c5b4b7563eb1f418bcfcfdbb06ebb4e7"
+ dependencies = [
+  "getrandom",
+-]
+-
+-[[package]]
+-name = "rand_hc"
+-version = "0.3.1"
+-source = "registry+https://github.com/rust-lang/crates.io-index"
+-checksum = "d51e9f596de227fda2ea6c84607f5558e196eeaf43c986b724ba4fb8fdf497e7"
+-dependencies = [
+- "rand_core",
+ ]
+ 
+ [[package]]
+ name = "signal-hook"
+ version = "0.3.13"
+diff --git a/third_party/rust/crossbeam-channel/Cargo.toml b/third_party/rust/crossbeam-channel/Cargo.toml
+--- a/third_party/rust/crossbeam-channel/Cargo.toml
++++ b/third_party/rust/crossbeam-channel/Cargo.toml
+@@ -11,24 +11,36 @@
+ 
+ [package]
+ edition = "2018"
+ rust-version = "1.36"
+ name = "crossbeam-channel"
+-version = "0.5.2"
++version = "0.5.4"
+ description = "Multi-producer multi-consumer channels for message passing"
+ homepage = "https://github.com/crossbeam-rs/crossbeam/tree/master/crossbeam-channel"
+-keywords = ["channel", "mpmc", "select", "golang", "message"]
+-categories = ["algorithms", "concurrency", "data-structures"]
++keywords = [
++    "channel",
++    "mpmc",
++    "select",
++    "golang",
++    "message",
++]
++categories = [
++    "algorithms",
++    "concurrency",
++    "data-structures",
++]
+ license = "MIT OR Apache-2.0"
+ repository = "https://github.com/crossbeam-rs/crossbeam"
++
+ [dependencies.cfg-if]
+ version = "1"
+ 
+ [dependencies.crossbeam-utils]
+ version = "0.8"
+ optional = true
+ default-features = false
++
+ [dev-dependencies.num_cpus]
+ version = "1.13.0"
+ 
+ [dev-dependencies.rand]
+ version = "0.8"
+diff --git a/third_party/rust/crossbeam-channel/src/channel.rs b/third_party/rust/crossbeam-channel/src/channel.rs
+--- a/third_party/rust/crossbeam-channel/src/channel.rs
++++ b/third_party/rust/crossbeam-channel/src/channel.rs
+@@ -12,10 +12,11 @@
+ use crate::err::{
+     RecvError, RecvTimeoutError, SendError, SendTimeoutError, TryRecvError, TrySendError,
+ };
+ use crate::flavors;
+ use crate::select::{Operation, SelectHandle, Token};
++use crate::utils;
+ 
+ /// Creates a channel of unbounded capacity.
+ ///
+ /// This channel has a growable buffer that can hold any number of messages at a time.
+ ///
+@@ -469,11 +470,11 @@
+     ///     s.send_timeout(3, Duration::from_millis(500)),
+     ///     Err(SendTimeoutError::Disconnected(3)),
+     /// );
+     /// ```
+     pub fn send_timeout(&self, msg: T, timeout: Duration) -> Result<(), SendTimeoutError<T>> {
+-        self.send_deadline(msg, Instant::now() + timeout)
++        self.send_deadline(msg, utils::convert_timeout_to_deadline(timeout))
+     }
+ 
+     /// Waits for a message to be sent into the channel, but only until a given deadline.
+     ///
+     /// If the channel is full and not disconnected, this call will block until the send operation
+@@ -859,11 +860,11 @@
+     ///     r.recv_timeout(Duration::from_secs(1)),
+     ///     Err(RecvTimeoutError::Disconnected),
+     /// );
+     /// ```
+     pub fn recv_timeout(&self, timeout: Duration) -> Result<T, RecvTimeoutError> {
+-        self.recv_deadline(Instant::now() + timeout)
++        self.recv_deadline(utils::convert_timeout_to_deadline(timeout))
+     }
+ 
+     /// Waits for a message to be received from the channel, but only before a given deadline.
+     ///
+     /// If the channel is empty and not disconnected, this call will block until the receive
+diff --git a/third_party/rust/crossbeam-channel/src/err.rs b/third_party/rust/crossbeam-channel/src/err.rs
+--- a/third_party/rust/crossbeam-channel/src/err.rs
++++ b/third_party/rust/crossbeam-channel/src/err.rs
+@@ -306,20 +306,18 @@
+     }
+ }
+ 
+ impl TryRecvError {
+     /// Returns `true` if the receive operation failed because the channel is empty.
+-    #[allow(clippy::trivially_copy_pass_by_ref)]
+     pub fn is_empty(&self) -> bool {
+         match self {
+             TryRecvError::Empty => true,
+             _ => false,
+         }
+     }
+ 
+     /// Returns `true` if the receive operation failed because the channel is disconnected.
+-    #[allow(clippy::trivially_copy_pass_by_ref)]
+     pub fn is_disconnected(&self) -> bool {
+         match self {
+             TryRecvError::Disconnected => true,
+             _ => false,
+         }
+@@ -345,20 +343,18 @@
+     }
+ }
+ 
+ impl RecvTimeoutError {
+     /// Returns `true` if the receive operation timed out.
+-    #[allow(clippy::trivially_copy_pass_by_ref)]
+     pub fn is_timeout(&self) -> bool {
+         match self {
+             RecvTimeoutError::Timeout => true,
+             _ => false,
+         }
+     }
+ 
+     /// Returns `true` if the receive operation failed because the channel is disconnected.
+-    #[allow(clippy::trivially_copy_pass_by_ref)]
+     pub fn is_disconnected(&self) -> bool {
+         match self {
+             RecvTimeoutError::Disconnected => true,
+             _ => false,
+         }
+diff --git a/third_party/rust/crossbeam-channel/src/flavors/array.rs b/third_party/rust/crossbeam-channel/src/flavors/array.rs
+--- a/third_party/rust/crossbeam-channel/src/flavors/array.rs
++++ b/third_party/rust/crossbeam-channel/src/flavors/array.rs
+@@ -7,11 +7,10 @@
+ //! Source:
+ //!   - <http://www.1024cores.net/home/lock-free-algorithms/queues/bounded-mpmc-queue>
+ //!   - <https://docs.google.com/document/d/1yIAYmbvL3JxOKOjuCyon7JhW4cSv1wy5hC0ApeGMV9s/pub>
+ 
+ use std::cell::UnsafeCell;
+-use std::marker::PhantomData;
+ use std::mem::MaybeUninit;
+ use std::ptr;
+ use std::sync::atomic::{self, AtomicUsize, Ordering};
+ use std::time::Instant;
+ 
+@@ -31,11 +30,11 @@
+     msg: UnsafeCell<MaybeUninit<T>>,
+ }
+ 
+ /// The token type for the array flavor.
+ #[derive(Debug)]
+-pub struct ArrayToken {
++pub(crate) struct ArrayToken {
+     /// Slot to read from or write to.
+     slot: *const u8,
+ 
+     /// Stamp to store into the slot after reading or writing.
+     stamp: usize,
+@@ -70,11 +69,11 @@
+     ///
+     /// Messages are pushed into the tail of the channel.
+     tail: CachePadded<AtomicUsize>,
+ 
+     /// The buffer holding slots.
+-    buffer: *mut Slot<T>,
++    buffer: Box<[Slot<T>]>,
+ 
+     /// The channel capacity.
+     cap: usize,
+ 
+     /// A stamp with the value of `{ lap: 1, mark: 0, index: 0 }`.
+@@ -86,13 +85,10 @@
+     /// Senders waiting while the channel is full.
+     senders: SyncWaker,
+ 
+     /// Receivers waiting while the channel is empty and not disconnected.
+     receivers: SyncWaker,
+-
+-    /// Indicates that dropping a `Channel<T>` may drop values of type `T`.
+-    _marker: PhantomData<T>,
+ }
+ 
+ impl<T> Channel<T> {
+     /// Creates a bounded channel of capacity `cap`.
+     pub(crate) fn with_capacity(cap: usize) -> Self {
+@@ -107,33 +103,29 @@
+         // Tail is initialized to `{ lap: 0, mark: 0, index: 0 }`.
+         let tail = 0;
+ 
+         // Allocate a buffer of `cap` slots initialized
+         // with stamps.
+-        let buffer = {
+-            let boxed: Box<[Slot<T>]> = (0..cap)
+-                .map(|i| {
+-                    // Set the stamp to `{ lap: 0, mark: 0, index: i }`.
+-                    Slot {
+-                        stamp: AtomicUsize::new(i),
+-                        msg: UnsafeCell::new(MaybeUninit::uninit()),
+-                    }
+-                })
+-                .collect();
+-            Box::into_raw(boxed) as *mut Slot<T>
+-        };
++        let buffer: Box<[Slot<T>]> = (0..cap)
++            .map(|i| {
++                // Set the stamp to `{ lap: 0, mark: 0, index: i }`.
++                Slot {
++                    stamp: AtomicUsize::new(i),
++                    msg: UnsafeCell::new(MaybeUninit::uninit()),
++                }
++            })
++            .collect();
+ 
+         Channel {
+             buffer,
+             cap,
+             one_lap,
+             mark_bit,
+             head: CachePadded::new(AtomicUsize::new(head)),
+             tail: CachePadded::new(AtomicUsize::new(tail)),
+             senders: SyncWaker::new(),
+             receivers: SyncWaker::new(),
+-            _marker: PhantomData,
+         }
+     }
+ 
+     /// Returns a receiver handle to the channel.
+     pub(crate) fn receiver(&self) -> Receiver<'_, T> {
+@@ -161,11 +153,12 @@
+             // Deconstruct the tail.
+             let index = tail & (self.mark_bit - 1);
+             let lap = tail & !(self.one_lap - 1);
+ 
+             // Inspect the corresponding slot.
+-            let slot = unsafe { &*self.buffer.add(index) };
++            debug_assert!(index < self.buffer.len());
++            let slot = unsafe { self.buffer.get_unchecked(index) };
+             let stamp = slot.stamp.load(Ordering::Acquire);
+ 
+             // If the tail and the stamp match, we may attempt to push.
+             if tail == stamp {
+                 let new_tail = if index + 1 < self.cap {
+@@ -243,11 +236,12 @@
+             // Deconstruct the head.
+             let index = head & (self.mark_bit - 1);
+             let lap = head & !(self.one_lap - 1);
+ 
+             // Inspect the corresponding slot.
+-            let slot = unsafe { &*self.buffer.add(index) };
++            debug_assert!(index < self.buffer.len());
++            let slot = unsafe { self.buffer.get_unchecked(index) };
+             let stamp = slot.stamp.load(Ordering::Acquire);
+ 
+             // If the the stamp is ahead of the head by 1, we may attempt to pop.
+             if head + 1 == stamp {
+                 let new = if index + 1 < self.cap {
+@@ -473,11 +467,10 @@
+             }
+         }
+     }
+ 
+     /// Returns the capacity of the channel.
+-    #[allow(clippy::unnecessary_wraps)] // This is intentional.
+     pub(crate) fn capacity(&self) -> Option<usize> {
+         Some(self.cap)
+     }
+ 
+     /// Disconnects the channel and wakes up all blocked senders and receivers.
+@@ -538,26 +531,15 @@
+             } else {
+                 hix + i - self.cap
+             };
+ 
+             unsafe {
+-                let p = {
+-                    let slot = &mut *self.buffer.add(index);
+-                    let msg = &mut *slot.msg.get();
+-                    msg.as_mut_ptr()
+-                };
+-                p.drop_in_place();
+-            }
+-        }
+-
+-        // Finally, deallocate the buffer, but don't run any destructors.
+-        unsafe {
+-            // Create a slice from the buffer to make
+-            // a fat pointer. Then, use Box::from_raw
+-            // to deallocate it.
+-            let ptr = std::slice::from_raw_parts_mut(self.buffer, self.cap) as *mut [Slot<T>];
+-            Box::from_raw(ptr);
++                debug_assert!(index < self.buffer.len());
++                let slot = self.buffer.get_unchecked_mut(index);
++                let msg = &mut *slot.msg.get();
++                msg.as_mut_ptr().drop_in_place();
++            }
+         }
+     }
+ }
+ 
+ /// Receiver handle to a channel.
+diff --git a/third_party/rust/crossbeam-channel/src/flavors/at.rs b/third_party/rust/crossbeam-channel/src/flavors/at.rs
+--- a/third_party/rust/crossbeam-channel/src/flavors/at.rs
++++ b/third_party/rust/crossbeam-channel/src/flavors/at.rs
+@@ -33,11 +33,11 @@
+         }
+     }
+     /// Creates a channel that delivers a message after a certain duration of time.
+     #[inline]
+     pub(crate) fn new_timeout(dur: Duration) -> Self {
+-        Self::new_deadline(Instant::now() + dur)
++        Self::new_deadline(utils::convert_timeout_to_deadline(dur))
+     }
+ 
+     /// Attempts to receive a message without blocking.
+     #[inline]
+     pub(crate) fn try_recv(&self) -> Result<Instant, TryRecvError> {
+@@ -140,11 +140,10 @@
+             1
+         }
+     }
+ 
+     /// Returns the capacity of the channel.
+-    #[allow(clippy::unnecessary_wraps)] // This is intentional.
+     #[inline]
+     pub(crate) fn capacity(&self) -> Option<usize> {
+         Some(1)
+     }
+ }
+diff --git a/third_party/rust/crossbeam-channel/src/flavors/list.rs b/third_party/rust/crossbeam-channel/src/flavors/list.rs
+--- a/third_party/rust/crossbeam-channel/src/flavors/list.rs
++++ b/third_party/rust/crossbeam-channel/src/flavors/list.rs
+@@ -124,11 +124,11 @@
+     block: AtomicPtr<Block<T>>,
+ }
+ 
+ /// The token type for the list flavor.
+ #[derive(Debug)]
+-pub struct ListToken {
++pub(crate) struct ListToken {
+     /// The block of slots.
+     block: *const u8,
+ 
+     /// The offset into the block.
+     offset: usize,
+diff --git a/third_party/rust/crossbeam-channel/src/flavors/never.rs b/third_party/rust/crossbeam-channel/src/flavors/never.rs
+--- a/third_party/rust/crossbeam-channel/src/flavors/never.rs
++++ b/third_party/rust/crossbeam-channel/src/flavors/never.rs
+@@ -63,11 +63,10 @@
+     pub(crate) fn len(&self) -> usize {
+         0
+     }
+ 
+     /// Returns the capacity of the channel.
+-    #[allow(clippy::unnecessary_wraps)] // This is intentional.
+     #[inline]
+     pub(crate) fn capacity(&self) -> Option<usize> {
+         Some(0)
+     }
+ }
+diff --git a/third_party/rust/crossbeam-channel/src/flavors/tick.rs b/third_party/rust/crossbeam-channel/src/flavors/tick.rs
+--- a/third_party/rust/crossbeam-channel/src/flavors/tick.rs
++++ b/third_party/rust/crossbeam-channel/src/flavors/tick.rs
+@@ -8,10 +8,11 @@
+ use crossbeam_utils::atomic::AtomicCell;
+ 
+ use crate::context::Context;
+ use crate::err::{RecvTimeoutError, TryRecvError};
+ use crate::select::{Operation, SelectHandle, Token};
++use crate::utils;
+ 
+ /// Result of a receive operation.
+ pub(crate) type TickToken = Option<Instant>;
+ 
+ /// Channel that delivers messages periodically.
+@@ -26,11 +27,11 @@
+ impl Channel {
+     /// Creates a channel that delivers messages periodically.
+     #[inline]
+     pub(crate) fn new(dur: Duration) -> Self {
+         Channel {
+-            delivery_time: AtomicCell::new(Instant::now() + dur),
++            delivery_time: AtomicCell::new(utils::convert_timeout_to_deadline(dur)),
+             duration: dur,
+         }
+     }
+ 
+     /// Attempts to receive a message without blocking.
+@@ -110,11 +111,10 @@
+             1
+         }
+     }
+ 
+     /// Returns the capacity of the channel.
+-    #[allow(clippy::unnecessary_wraps)] // This is intentional.
+     #[inline]
+     pub(crate) fn capacity(&self) -> Option<usize> {
+         Some(1)
+     }
+ }
+diff --git a/third_party/rust/crossbeam-channel/src/flavors/zero.rs b/third_party/rust/crossbeam-channel/src/flavors/zero.rs
+--- a/third_party/rust/crossbeam-channel/src/flavors/zero.rs
++++ b/third_party/rust/crossbeam-channel/src/flavors/zero.rs
+@@ -15,11 +15,11 @@
+ use crate::select::{Operation, SelectHandle, Selected, Token};
+ use crate::utils::Spinlock;
+ use crate::waker::Waker;
+ 
+ /// A pointer to a packet.
+-pub struct ZeroToken(*mut ());
++pub(crate) struct ZeroToken(*mut ());
+ 
+ impl Default for ZeroToken {
+     fn default() -> Self {
+         Self(ptr::null_mut())
+     }
+@@ -361,11 +361,10 @@
+     pub(crate) fn len(&self) -> usize {
+         0
+     }
+ 
+     /// Returns the capacity of the channel.
+-    #[allow(clippy::unnecessary_wraps)] // This is intentional.
+     pub(crate) fn capacity(&self) -> Option<usize> {
+         Some(0)
+     }
+ 
+     /// Returns `true` if the channel is empty.
+diff --git a/third_party/rust/crossbeam-channel/src/select.rs b/third_party/rust/crossbeam-channel/src/select.rs
+--- a/third_party/rust/crossbeam-channel/src/select.rs
++++ b/third_party/rust/crossbeam-channel/src/select.rs
+@@ -20,16 +20,17 @@
+ ///
+ /// Each field contains data associated with a specific channel flavor.
+ // This is a private API that is used by the select macro.
+ #[derive(Debug, Default)]
+ pub struct Token {
+-    pub at: flavors::at::AtToken,
+-    pub array: flavors::array::ArrayToken,
+-    pub list: flavors::list::ListToken,
+-    pub never: flavors::never::NeverToken,
+-    pub tick: flavors::tick::TickToken,
+-    pub zero: flavors::zero::ZeroToken,
++    pub(crate) at: flavors::at::AtToken,
++    pub(crate) array: flavors::array::ArrayToken,
++    pub(crate) list: flavors::list::ListToken,
++    #[allow(dead_code)]
++    pub(crate) never: flavors::never::NeverToken,
++    pub(crate) tick: flavors::tick::TickToken,
++    pub(crate) zero: flavors::zero::ZeroToken,
+ }
+ 
+ /// Identifier associated with an operation by a specific thread on a specific channel.
+ #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+ pub struct Operation(usize);
+@@ -484,11 +485,11 @@
+ #[inline]
+ pub fn select_timeout<'a>(
+     handles: &mut [(&'a dyn SelectHandle, usize, *const u8)],
+     timeout: Duration,
+ ) -> Result<SelectedOperation<'a>, SelectTimeoutError> {
+-    select_deadline(handles, Instant::now() + timeout)
++    select_deadline(handles, utils::convert_timeout_to_deadline(timeout))
+ }
+ 
+ /// Blocks until a given deadline, or until one of the operations becomes ready and selects it.
+ #[inline]
+ pub(crate) fn select_deadline<'a>(
+@@ -1040,11 +1041,11 @@
+     ///     Ok(i) if i == oper2 => assert_eq!(r2.try_recv(), Ok(20)),
+     ///     Ok(_) => unreachable!(),
+     /// }
+     /// ```
+     pub fn ready_timeout(&mut self, timeout: Duration) -> Result<usize, ReadyTimeoutError> {
+-        self.ready_deadline(Instant::now() + timeout)
++        self.ready_deadline(utils::convert_timeout_to_deadline(timeout))
+     }
+ 
+     /// Blocks until a given deadline, or until one of the operations becomes ready.
+     ///
+     /// If an operation becomes ready, its index is returned. If multiple operations are ready at
+diff --git a/third_party/rust/crossbeam-channel/src/select_macro.rs b/third_party/rust/crossbeam-channel/src/select_macro.rs
+--- a/third_party/rust/crossbeam-channel/src/select_macro.rs
++++ b/third_party/rust/crossbeam-channel/src/select_macro.rs
+@@ -119,22 +119,11 @@
+             ($($head)* $case ($($args)*) $(-> $res)* => { $body },)
+         )
+     };
+     // Only one case remains.
+     (@list
+-        ($case:ident ($($args:tt)*) $(-> $res:pat)* => $body:expr)
+-        ($($head:tt)*)
+-    ) => {
+-        $crate::crossbeam_channel_internal!(
+-            @list
+-            ()
+-            ($($head)* $case ($($args)*) $(-> $res)* => { $body },)
+-        )
+-    };
+-    // Accept a trailing comma at the end of the list.
+-    (@list
+-        ($case:ident ($($args:tt)*) $(-> $res:pat)* => $body:expr,)
++        ($case:ident ($($args:tt)*) $(-> $res:pat)* => $body:expr $(,)?)
+         ($($head:tt)*)
+     ) => {
+         $crate::crossbeam_channel_internal!(
+             @list
+             ()
+@@ -371,34 +360,21 @@
+         )
+     };
+ 
+     // Check the format of a recv case.
+     (@case
+-        (recv($r:expr) -> $res:pat => $body:tt, $($tail:tt)*)
++        (recv($r:expr $(,)?) -> $res:pat => $body:tt, $($tail:tt)*)
+         ($($cases:tt)*)
+         $default:tt
+     ) => {
+         $crate::crossbeam_channel_internal!(
+             @case
+             ($($tail)*)
+             ($($cases)* recv($r) -> $res => $body,)
+             $default
+         )
+     };
+-    // Allow trailing comma...
+-    (@case
+-        (recv($r:expr,) -> $res:pat => $body:tt, $($tail:tt)*)
+-        ($($cases:tt)*)
+-        $default:tt
+-    ) => {
+-        $crate::crossbeam_channel_internal!(
+-            @case
+-            ($($tail)*)
+-            ($($cases)* recv($r) -> $res => $body,)
+-            $default
+-        )
+-    };
+     // Print an error if the argument list is invalid.
+     (@case
+         (recv($($args:tt)*) -> $res:pat => $body:tt, $($tail:tt)*)
+         ($($cases:tt)*)
+         $default:tt
+@@ -426,34 +402,21 @@
+         )
+     };
+ 
+     // Check the format of a send case.
+     (@case
+-        (send($s:expr, $m:expr) -> $res:pat => $body:tt, $($tail:tt)*)
++        (send($s:expr, $m:expr $(,)?) -> $res:pat => $body:tt, $($tail:tt)*)
+         ($($cases:tt)*)
+         $default:tt
+     ) => {
+         $crate::crossbeam_channel_internal!(
+             @case
+             ($($tail)*)
+             ($($cases)* send($s, $m) -> $res => $body,)
+             $default
+         )
+     };
+-    // Allow trailing comma...
+-    (@case
+-        (send($s:expr, $m:expr,) -> $res:pat => $body:tt, $($tail:tt)*)
+-        ($($cases:tt)*)
+-        $default:tt
+-    ) => {
+-        $crate::crossbeam_channel_internal!(
+-            @case
+-            ($($tail)*)
+-            ($($cases)* send($s, $m) -> $res => $body,)
+-            $default
+-        )
+-    };
+     // Print an error if the argument list is invalid.
+     (@case
+         (send($($args:tt)*) -> $res:pat => $body:tt, $($tail:tt)*)
+         ($($cases:tt)*)
+         $default:tt
+@@ -494,24 +457,11 @@
+             (default() => $body,)
+         )
+     };
+     // Check the format of a default case with timeout.
+     (@case
+-        (default($timeout:expr) => $body:tt, $($tail:tt)*)
+-        $cases:tt
+-        ()
+-    ) => {
+-        $crate::crossbeam_channel_internal!(
+-            @case
+-            ($($tail)*)
+-            $cases
+-            (default($timeout) => $body,)
+-        )
+-    };
+-    // Allow trailing comma...
+-    (@case
+-        (default($timeout:expr,) => $body:tt, $($tail:tt)*)
++        (default($timeout:expr $(,)?) => $body:tt, $($tail:tt)*)
+         $cases:tt
+         ()
+     ) => {
+         $crate::crossbeam_channel_internal!(
+             @case
+diff --git a/third_party/rust/crossbeam-channel/src/utils.rs b/third_party/rust/crossbeam-channel/src/utils.rs
+--- a/third_party/rust/crossbeam-channel/src/utils.rs
++++ b/third_party/rust/crossbeam-channel/src/utils.rs
+@@ -59,10 +59,18 @@
+             }
+         }
+     }
+ }
+ 
++// https://github.com/crossbeam-rs/crossbeam/issues/795
++pub(crate) fn convert_timeout_to_deadline(timeout: Duration) -> Instant {
++    match Instant::now().checked_add(timeout) {
++        Some(deadline) => deadline,
++        None => Instant::now() + Duration::from_secs(86400 * 365 * 30),
++    }
++}
++
+ /// A simple spinlock.
+ pub(crate) struct Spinlock<T> {
+     flag: AtomicBool,
+     value: UnsafeCell<T>,
+ }
+diff --git a/third_party/rust/crossbeam-channel/src/waker.rs b/third_party/rust/crossbeam-channel/src/waker.rs
+--- a/third_party/rust/crossbeam-channel/src/waker.rs
++++ b/third_party/rust/crossbeam-channel/src/waker.rs
+@@ -75,30 +75,36 @@
+     }
+ 
+     /// Attempts to find another thread's entry, select the operation, and wake it up.
+     #[inline]
+     pub(crate) fn try_select(&mut self) -> Option<Entry> {
+-        self.selectors
+-            .iter()
+-            .position(|selector| {
+-                // Does the entry belong to a different thread?
+-                selector.cx.thread_id() != current_thread_id()
+-                    && selector // Try selecting this operation.
+-                        .cx
+-                        .try_select(Selected::Operation(selector.oper))
+-                        .is_ok()
+-                    && {
+-                        // Provide the packet.
+-                        selector.cx.store_packet(selector.packet);
+-                        // Wake the thread up.
+-                        selector.cx.unpark();
+-                        true
+-                    }
+-            })
+-            // Remove the entry from the queue to keep it clean and improve
+-            // performance.
+-            .map(|pos| self.selectors.remove(pos))
++        if self.selectors.is_empty() {
++            None
++        } else {
++            let thread_id = current_thread_id();
++
++            self.selectors
++                .iter()
++                .position(|selector| {
++                    // Does the entry belong to a different thread?
++                    selector.cx.thread_id() != thread_id
++                        && selector // Try selecting this operation.
++                            .cx
++                            .try_select(Selected::Operation(selector.oper))
++                            .is_ok()
++                        && {
++                            // Provide the packet.
++                            selector.cx.store_packet(selector.packet);
++                            // Wake the thread up.
++                            selector.cx.unpark();
++                            true
++                        }
++                })
++                // Remove the entry from the queue to keep it clean and improve
++                // performance.
++                .map(|pos| self.selectors.remove(pos))
++        }
+     }
+ 
+     /// Returns `true` if there is an entry which can be selected by the current thread.
+     #[inline]
+     pub(crate) fn can_select(&self) -> bool {
+diff --git a/third_party/rust/crossbeam-channel/tests/array.rs b/third_party/rust/crossbeam-channel/tests/array.rs
+--- a/third_party/rust/crossbeam-channel/tests/array.rs
++++ b/third_party/rust/crossbeam-channel/tests/array.rs
+@@ -1,8 +1,6 @@
+ //! Tests for the array channel flavor.
+-
+-#![cfg(not(miri))] // TODO: many assertions failed due to Miri is slow
+ 
+ use std::any::Any;
+ use std::sync::atomic::AtomicUsize;
+ use std::sync::atomic::Ordering;
+ use std::thread;
+@@ -252,11 +250,17 @@
+     assert_eq!(r.recv(), Err(RecvError));
+ }
+ 
+ #[test]
+ fn len() {
++    #[cfg(miri)]
++    const COUNT: usize = 250;
++    #[cfg(not(miri))]
+     const COUNT: usize = 25_000;
++    #[cfg(miri)]
++    const CAP: usize = 100;
++    #[cfg(not(miri))]
+     const CAP: usize = 1000;
+ 
+     let (s, r) = bounded(CAP);
+ 
+     assert_eq!(s.len(), 0);
+@@ -345,10 +349,13 @@
+     .unwrap();
+ }
+ 
+ #[test]
+ fn spsc() {
++    #[cfg(miri)]
++    const COUNT: usize = 100;
++    #[cfg(not(miri))]
+     const COUNT: usize = 100_000;
+ 
+     let (s, r) = bounded(3);
+ 
+     scope(|scope| {
+@@ -367,10 +374,13 @@
+     .unwrap();
+ }
+ 
+ #[test]
+ fn mpmc() {
++    #[cfg(miri)]
++    const COUNT: usize = 100;
++    #[cfg(not(miri))]
+     const COUNT: usize = 25_000;
+     const THREADS: usize = 4;
+ 
+     let (s, r) = bounded::<usize>(3);
+     let v = (0..COUNT).map(|_| AtomicUsize::new(0)).collect::<Vec<_>>();
+@@ -399,10 +409,13 @@
+     }
+ }
+ 
+ #[test]
+ fn stress_oneshot() {
++    #[cfg(miri)]
++    const COUNT: usize = 100;
++    #[cfg(not(miri))]
+     const COUNT: usize = 10_000;
+ 
+     for _ in 0..COUNT {
+         let (s, r) = bounded(1);
+ 
+@@ -414,10 +427,13 @@
+     }
+ }
+ 
+ #[test]
+ fn stress_iter() {
++    #[cfg(miri)]
++    const COUNT: usize = 100;
++    #[cfg(not(miri))]
+     const COUNT: usize = 100_000;
+ 
+     let (request_s, request_r) = bounded(1);
+     let (response_s, response_r) = bounded(1);
+ 
+@@ -479,10 +495,11 @@
+         });
+     })
+     .unwrap();
+ }
+ 
++#[cfg_attr(miri, ignore)] // Miri is too slow
+ #[test]
+ fn drops() {
+     const RUNS: usize = 100;
+ 
+     static DROPS: AtomicUsize = AtomicUsize::new(0);
+@@ -531,10 +548,13 @@
+     }
+ }
+ 
+ #[test]
+ fn linearizable() {
++    #[cfg(miri)]
++    const COUNT: usize = 100;
++    #[cfg(not(miri))]
+     const COUNT: usize = 25_000;
+     const THREADS: usize = 4;
+ 
+     let (s, r) = bounded(THREADS);
+ 
+@@ -551,10 +571,13 @@
+     .unwrap();
+ }
+ 
+ #[test]
+ fn fairness() {
++    #[cfg(miri)]
++    const COUNT: usize = 100;
++    #[cfg(not(miri))]
+     const COUNT: usize = 10_000;
+ 
+     let (s1, r1) = bounded::<()>(COUNT);
+     let (s2, r2) = bounded::<()>(COUNT);
+ 
+@@ -573,10 +596,13 @@
+     assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+ }
+ 
+ #[test]
+ fn fairness_duplicates() {
++    #[cfg(miri)]
++    const COUNT: usize = 100;
++    #[cfg(not(miri))]
+     const COUNT: usize = 10_000;
+ 
+     let (s, r) = bounded::<()>(COUNT);
+ 
+     for _ in 0..COUNT {
+@@ -617,10 +643,13 @@
+     }
+ }
+ 
+ #[test]
+ fn channel_through_channel() {
++    #[cfg(miri)]
++    const COUNT: usize = 100;
++    #[cfg(not(miri))]
+     const COUNT: usize = 1000;
+ 
+     type T = Box<dyn Any + Send>;
+ 
+     let (s, r) = bounded::<T>(1);
+@@ -652,5 +681,58 @@
+             }
+         });
+     })
+     .unwrap();
+ }
++
++#[test]
++fn panic_on_drop() {
++    struct Msg1<'a>(&'a mut bool);
++    impl Drop for Msg1<'_> {
++        fn drop(&mut self) {
++            if *self.0 && !std::thread::panicking() {
++                panic!("double drop");
++            } else {
++                *self.0 = true;
++            }
++        }
++    }
++
++    struct Msg2<'a>(&'a mut bool);
++    impl Drop for Msg2<'_> {
++        fn drop(&mut self) {
++            if *self.0 {
++                panic!("double drop");
++            } else {
++                *self.0 = true;
++                panic!("first drop");
++            }
++        }
++    }
++
++    // normal
++    let (s, r) = bounded(2);
++    let (mut a, mut b) = (false, false);
++    s.send(Msg1(&mut a)).unwrap();
++    s.send(Msg1(&mut b)).unwrap();
++    drop(s);
++    drop(r);
++    assert!(a);
++    assert!(b);
++
++    // panic on drop
++    let (s, r) = bounded(2);
++    let (mut a, mut b) = (false, false);
++    s.send(Msg2(&mut a)).unwrap();
++    s.send(Msg2(&mut b)).unwrap();
++    drop(s);
++    let res = std::panic::catch_unwind(move || {
++        drop(r);
++    });
++    assert_eq!(
++        *res.unwrap_err().downcast_ref::<&str>().unwrap(),
++        "first drop"
++    );
++    assert!(a);
++    // Elements after the panicked element will leak.
++    assert!(!b);
++}
+diff --git a/third_party/rust/crossbeam-channel/tests/select_macro.rs b/third_party/rust/crossbeam-channel/tests/select_macro.rs
+--- a/third_party/rust/crossbeam-channel/tests/select_macro.rs
++++ b/third_party/rust/crossbeam-channel/tests/select_macro.rs
+@@ -1466,5 +1466,16 @@
+             drop(s);
+         });
+     })
+     .unwrap();
+ }
++
++#[test]
++fn trailing_comma() {
++    let (s, r) = unbounded::<usize>();
++
++    select! {
++        send(s, 1,) -> _ => {},
++        recv(r,) -> _ => {},
++        default(ms(1000),) => {},
++    }
++}
+