From 71a4f2cee17cb03123675d378e990f8fb6693751 Mon Sep 17 00:00:00 2001
From: Justin Collins <justin@presidentbeef.com>
Date: Mon, 21 Oct 2024 23:50:22 -0600
Subject: [PATCH] Fix recursion in masgn

Fixes #1877
---
 lib/brakeman/processors/alias_processor.rb | 4 +++-
 test/apps/rails8/lib/masgn.rb              | 7 +++++++
 2 files changed, 10 insertions(+), 1 deletion(-)
 create mode 100644 test/apps/rails8/lib/masgn.rb

diff --git a/lib/brakeman/processors/alias_processor.rb b/lib/brakeman/processors/alias_processor.rb
index cfd1c04e0..ab4177337 100644
--- a/lib/brakeman/processors/alias_processor.rb
+++ b/lib/brakeman/processors/alias_processor.rb
@@ -666,7 +666,9 @@ def process_masgn exp
     end
 
     unless array? exp[1] and array? exp[2]
-      return process_default(exp)
+      # Already processed RHS, don't do it again
+      # https://github.com/presidentbeef/brakeman/issues/1877
+      return exp
     end
 
     vars = exp[1].dup
diff --git a/test/apps/rails8/lib/masgn.rb b/test/apps/rails8/lib/masgn.rb
new file mode 100644
index 000000000..36dbdfecf
--- /dev/null
+++ b/test/apps/rails8/lib/masgn.rb
@@ -0,0 +1,7 @@
+def test_masgn_recursion
+  r = lambda {
+    x, q = r
+  }
+
+  y, z = r
+end