From a8fb272bfd44cc0cbb70b73731e9f2cea8355f62 Mon Sep 17 00:00:00 2001
From: Mikael Magnusson <mikma@users.sourceforge.net>
Date: Wed, 1 Oct 2025 00:53:08 +0200
Subject: [PATCH] Fix realloc with size == 0 in dbuf_default_realloc()

If the new_size argument to realloc is zero, the behavior
is undefined since C23.
---
 cutils.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/cutils.c b/cutils.c
index b41eda355..7d36ddfdb 100644
--- a/cutils.c
+++ b/cutils.c
@@ -102,6 +102,10 @@ int js__has_suffix(const char *str, const char *suffix)
 
 static void *dbuf_default_realloc(void *opaque, void *ptr, size_t size)
 {
+    if (unlikely(size == 0)) {
+        free(ptr);
+        return NULL;
+    }
     return realloc(ptr, size);
 }