From 4e949a1cc3bad04069bf6438d23569de29a12175 Mon Sep 17 00:00:00 2001
From: Smit Barmase <heysmitbarmase@gmail.com>
Date: Tue, 2 Jun 2026 18:51:32 +0530
Subject: [PATCH] mermaid: Fix stack overflow when laying out deeply nested
 subgraphs (#58325)

Closes FR-49

This PR fixes stack overflow in flowcharts with deeply nested subgraphs.
Rewrote recursive call to iterate with an explicit stack on heap. Added
test which reproduces the overflow.

We use our fork now, with patch on existing v0.4.0:
https://github.com/zed-industries/merman/commit/1c765dcca2ef5092fcde7bebe8374819563623ef

Release Notes:

- Fixed a crash in when rendering Mermaid diagram flowcharts with deeply
nested subgraphs.
---
 Cargo.lock                       | 21 +++++++--------------
 crates/mermaid_render/Cargo.toml |  2 +-
 2 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 17bd0a8319..0c3bf9c13b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5459,8 +5459,7 @@ dependencies = [
 [[package]]
 name = "dugong"
 version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3f5b0a9f36306eb29685e6e27b82df4d0bb5af64261324f7d5f7716d7c39ba1b"
+source = "git+https://github.com/zed-industries/merman?rev=1c765dcca2ef5092fcde7bebe8374819563623ef#1c765dcca2ef5092fcde7bebe8374819563623ef"
 dependencies = [
  "dugong-graphlib",
  "rustc-hash 2.1.1",
@@ -5471,8 +5470,7 @@ dependencies = [
 [[package]]
 name = "dugong-graphlib"
 version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "75aca4df30a85b3ba8cead498f4e38e9de4aff630155ce47515d11dfd729c6ea"
+source = "git+https://github.com/zed-industries/merman?rev=1c765dcca2ef5092fcde7bebe8374819563623ef#1c765dcca2ef5092fcde7bebe8374819563623ef"
 dependencies = [
  "hashbrown 0.16.1",
  "rustc-hash 2.1.1",
@@ -10953,8 +10951,7 @@ dependencies = [
 [[package]]
 name = "manatee"
 version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6c5ed3cc0bf5f911d242bed4b4cdf12c00186e471e9fdf57d9dd0a033bbbdc87"
+source = "git+https://github.com/zed-industries/merman?rev=1c765dcca2ef5092fcde7bebe8374819563623ef#1c765dcca2ef5092fcde7bebe8374819563623ef"
 dependencies = [
  "indexmap 2.11.4",
  "nalgebra",
@@ -11250,8 +11247,7 @@ dependencies = [
 [[package]]
 name = "merman"
 version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3209bcfe9c8e9787a7534f8d97f1d27f7d2fdd54d3c49d9f59bb693aedabbf95"
+source = "git+https://github.com/zed-industries/merman?rev=1c765dcca2ef5092fcde7bebe8374819563623ef#1c765dcca2ef5092fcde7bebe8374819563623ef"
 dependencies = [
  "merman-core",
  "merman-render",
@@ -11261,8 +11257,7 @@ dependencies = [
 [[package]]
 name = "merman-core"
 version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "72fc438439ca428b449486f8eaf9ce2f8ab76cea159181d0b1b454e1192e4649"
+source = "git+https://github.com/zed-industries/merman?rev=1c765dcca2ef5092fcde7bebe8374819563623ef#1c765dcca2ef5092fcde7bebe8374819563623ef"
 dependencies = [
  "chrono",
  "euclid",
@@ -11288,8 +11283,7 @@ dependencies = [
 [[package]]
 name = "merman-render"
 version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b5698e2681196051479ae8bc5153ed7eda6490f56240fd8d92da7c3932a00735"
+source = "git+https://github.com/zed-industries/merman?rev=1c765dcca2ef5092fcde7bebe8374819563623ef#1c765dcca2ef5092fcde7bebe8374819563623ef"
 dependencies = [
  "base64 0.22.1",
  "chrono",
@@ -15881,8 +15875,7 @@ dependencies = [
 [[package]]
 name = "roughr-merman"
 version = "0.12.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c34fd013a888d8b2119b3ed57cd3df0f1f9dd2db3fa94fdb98f58d60f9855ef0"
+source = "git+https://github.com/zed-industries/merman?rev=1c765dcca2ef5092fcde7bebe8374819563623ef#1c765dcca2ef5092fcde7bebe8374819563623ef"
 dependencies = [
  "derive_builder",
  "euclid",
diff --git a/crates/mermaid_render/Cargo.toml b/crates/mermaid_render/Cargo.toml
index 73a32ba81f..6706e028d1 100644
--- a/crates/mermaid_render/Cargo.toml
+++ b/crates/mermaid_render/Cargo.toml
@@ -18,7 +18,7 @@ test-support = []
 [dependencies]
 anyhow.workspace = true
 gpui.workspace = true
-merman = { version = "0.4", features = ["render"] }
+merman = { git = "https://github.com/zed-industries/merman", rev = "1c765dcca2ef5092fcde7bebe8374819563623ef", features = ["render"] }
 quick-xml.workspace = true
 serde_json.workspace = true