From c71cd27c98f1007e462259522217797e9923db32 Mon Sep 17 00:00:00 2001
From: Jakob Botsch Nielsen <jakob.botsch.nielsen@gmail.com>
Date: Mon, 6 Jan 2025 19:39:45 +0100
Subject: [PATCH] JIT: Check DFS tree containment before checking ancestry

Fix #110957
---
 src/coreclr/jit/optimizer.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/coreclr/jit/optimizer.cpp b/src/coreclr/jit/optimizer.cpp
index e12a377e2c1f8..fbd05f5e8ea40 100644
--- a/src/coreclr/jit/optimizer.cpp
+++ b/src/coreclr/jit/optimizer.cpp
@@ -5730,7 +5730,7 @@ void Compiler::optRemoveRedundantZeroInits()
                  predEdge           = predEdge->getNextPredEdge())
             {
                 BasicBlock* const predBlock = predEdge->getSourceBlock();
-                if (m_dfsTree->IsAncestor(block, predBlock))
+                if (m_dfsTree->Contains(predBlock) && m_dfsTree->IsAncestor(block, predBlock))
                 {
                     JITDUMP(FMT_BB " is part of a cycle, stopping the block scan\n", block->bbNum);
                     stop = true;