fix: Don't panic lsp writer thread on dropped receiver

Cargo.lock

@@ -998,23 +998,23 @@ checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"
 [[package]]
 name = "lsp-server"
 version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "248f65b78f6db5d8e1b1604b4098a28b43d21a8eb1deeca22b1c421b276c7095"
 dependencies = [
  "crossbeam-channel",
- "ctrlc",
  "log",
- "lsp-types",
  "serde",
  "serde_json",
 ]
 
 [[package]]
 name = "lsp-server"
-version = "0.7.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "248f65b78f6db5d8e1b1604b4098a28b43d21a8eb1deeca22b1c421b276c7095"
+version = "0.7.7"
 dependencies = [
  "crossbeam-channel",
+ "ctrlc",
  "log",
+ "lsp-types",
  "serde",
  "serde_json",
 ]
@@ -1652,7 +1652,7 @@ dependencies = [
  "intern",
  "itertools",
  "load-cargo",
- "lsp-server 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lsp-server 0.7.6",
  "lsp-types",
  "memchr",
  "mimalloc",

lib/lsp-server/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "lsp-server"
-version = "0.7.6"
+version = "0.7.7"
 description = "Generic LSP server scaffold."
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-lang/rust-analyzer/tree/master/lib/lsp-server"

lib/lsp-server/src/stdio.rs

@@ -30,7 +30,9 @@ pub(crate) fn stdio_transport() -> (Sender<Message>, Receiver<Message>, IoThread
                 let is_exit = matches!(&msg, Message::Notification(n) if n.is_exit());
 
                 debug!("sending message {:#?}", msg);
-                reader_sender.send(msg).expect("receiver was dropped, failed to send a message");
+                if let Err(e) = reader_sender.send(msg) {
+                    return Err(io::Error::new(io::ErrorKind::Other, e));
+                }
 
                 if is_exit {
                     break;
@@ -60,15 +62,11 @@ impl IoThreads {
     pub fn join(self) -> io::Result<()> {
         match self.reader.join() {
             Ok(r) => r?,
-            Err(err) => {
-                println!("reader panicked!");
-                std::panic::panic_any(err)
-            }
+            Err(err) => std::panic::panic_any(err),
         }
         match self.writer.join() {
             Ok(r) => r,
             Err(err) => {
-                println!("writer panicked!");
                 std::panic::panic_any(err);
             }
         }