From 360074effbab6c16af40f87095911856ce9658d7 Mon Sep 17 00:00:00 2001
From: Lukas Wirth <lukas@zed.dev>
Date: Tue, 28 Oct 2025 21:21:49 +0100
Subject: [PATCH] rope: Prevent stack overflows by bumping rayon stack sizes
 (#41397)

Thread stacks in rust by default have 2 megabytes of stack which for
sumtrees (or ropes in this case) can easily be exceeded depending on the
workload.

Release Notes:

- Fixed stack overflows when constructing large ropes
---
 crates/cli/src/main.rs           | 1 +
 crates/remote_server/src/unix.rs | 1 +
 crates/rope/src/rope.rs          | 8 ++++----
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/crates/cli/src/main.rs b/crates/cli/src/main.rs
index bb2f2effbbf8ff0d8995b8607c1ce2ddff66ac0c..a16f5a3bab9849ee93abac4e2eccb602698b65de 100644
--- a/crates/cli/src/main.rs
+++ b/crates/cli/src/main.rs
@@ -358,6 +358,7 @@ fn main() -> Result<()> {
 
     rayon::ThreadPoolBuilder::new()
         .num_threads(4)
+        .stack_size(10 * 1024 * 1024)
         .thread_name(|ix| format!("RayonWorker{}", ix))
         .build_global()
         .unwrap();
diff --git a/crates/remote_server/src/unix.rs b/crates/remote_server/src/unix.rs
index 1a7dc8c9621354a385a65567960a6215f680528c..d11fb4031e6386e66090b1cfb106dd5d0a7dac05 100644
--- a/crates/remote_server/src/unix.rs
+++ b/crates/remote_server/src/unix.rs
@@ -372,6 +372,7 @@ pub fn execute_run(
 
     rayon::ThreadPoolBuilder::new()
         .num_threads(4)
+        .stack_size(10 * 1024 * 1024)
         .thread_name(|ix| format!("RayonWorker{}", ix))
         .build_global()
         .unwrap();
diff --git a/crates/rope/src/rope.rs b/crates/rope/src/rope.rs
index c61346e0376bf8c97cd2af3a454f20953f6eaed9..394e6ef0ca589d19ffcf7cf07a92bcd15c8e4a18 100644
--- a/crates/rope/src/rope.rs
+++ b/crates/rope/src/rope.rs
@@ -191,9 +191,9 @@ impl Rope {
             (),
         );
 
-        #[cfg(not(test))]
+        #[cfg(all(test, not(rust_analyzer)))]
         const NUM_CHUNKS: usize = 16;
-        #[cfg(test)]
+        #[cfg(not(all(test, not(rust_analyzer))))]
         const NUM_CHUNKS: usize = 4;
 
         // We accommodate for NUM_CHUNKS chunks of size MAX_BASE
@@ -248,9 +248,9 @@ impl Rope {
             text = remainder;
         }
 
-        #[cfg(test)]
+        #[cfg(all(test, not(rust_analyzer)))]
         const PARALLEL_THRESHOLD: usize = 4;
-        #[cfg(not(test))]
+        #[cfg(not(all(test, not(rust_analyzer))))]
         const PARALLEL_THRESHOLD: usize = 4 * (2 * sum_tree::TREE_BASE);
 
         if new_chunks.len() >= PARALLEL_THRESHOLD {