From 21633377174354199c3ea3e4b23f64cfaeacc50a Mon Sep 17 00:00:00 2001
From: "Christoph M. Becker" <cmbecker69@gmx.de>
Date: Thu, 26 Dec 2024 11:56:38 +0100
Subject: [PATCH] Avoid segfault of bug788 (#907)

If the heif image can't be created for whatever reason, `dst` is `NULL`
what causes a segfault when we try to access its dimensions.  We catch
that with a test assertion, and bail out if that fails.
---
 tests/heif/bug788.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tests/heif/bug788.c b/tests/heif/bug788.c
index 5475251b6..2e2a9ea6f 100644
--- a/tests/heif/bug788.c
+++ b/tests/heif/bug788.c
@@ -24,6 +24,10 @@ int main () {
     data = gdImageHeifPtrEx(in, &size, 200, GD_HEIF_CODEC_HEVC, GD_HEIF_CHROMA_444);
 
     dst = gdImageCreateFromHeifPtr(size, data);
+    if (!gdTestAssert(dst != NULL)) {
+        gdImageDestroy(in);
+        return gdNumFailures();
+    }
     diff = gdImageCreateTrueColor(gdImageSX(dst), gdImageSY(dst));
     if (gdTestAssertMsg(dst != NULL, "cannot compare with NULL buffer")) {
         gdTestImageDiff(in, dst, diff, &result);