From bd5771ff27dbbb2b09cc7c14f1ac040234285acc Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Wed, 26 Aug 2020 00:07:08 -0700
Subject: [PATCH] regex-emacs: fix leak on memory allocation failure

* src/regex-emacs.c (ENSURE_FAIL_STACK): If the failure
stack cannot be grown, free locally-allocated storage
before returning.
---
 src/regex-emacs.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/regex-emacs.c b/src/regex-emacs.c
index 5d1bb094d53..3d8aaf4bb13 100644
--- a/src/regex-emacs.c
+++ b/src/regex-emacs.c
@@ -969,7 +969,11 @@ typedef struct
 #define ENSURE_FAIL_STACK(space)					\
 while (REMAINING_AVAIL_SLOTS <= space) {				\
   if (!GROW_FAIL_STACK (fail_stack))					\
-    return -2;								\
+    {									\
+      unbind_to (count, Qnil);						\
+      SAFE_FREE ();							\
+      return -2;							\
+    }									\
   DEBUG_PRINT ("\n  Doubled stack; size now: %td\n", fail_stack.size);	\
   DEBUG_PRINT ("	 slots available: %td\n", REMAINING_AVAIL_SLOTS);\
 }
-- 
2.39.2