From 453d28fcc0fa9dcd35ecd0050d8cec395bb161f2 Mon Sep 17 00:00:00 2001
From: Tor Andersson <tor.andersson@artifex.com>
Date: Sun, 1 Aug 2021 13:58:34 +0200
Subject: [PATCH] Don't use realloc(p, 0) to mean free() in default regex
 allocator.

---
 regexp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/regexp.c b/regexp.c
index 3f6c074..9d16867 100644
--- a/regexp.c
+++ b/regexp.c
@@ -943,6 +943,10 @@ void regfreex(void *(*alloc)(void *ctx, void *p, int n), void *ctx, Reprog *prog
 
 static void *default_alloc(void *ctx, void *p, int n)
 {
+	if (n == 0) {
+		free(p);
+		return NULL;
+	}
 	return realloc(p, (size_t)n);
 }