SDL_image: IMG_libpng.c: fix a bogus -Wuninitialized from old gcc versions. (cdab1)

SDL Commits
1 
From cdab180a8ae0e6b1799b4a50eca5622bc4d74f9f Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Fri, 1 May 2026 07:56:10 +0300
Subject: [PATCH] IMG_libpng.c: fix a bogus -Wuninitialized from old gcc
 versions.

(cherry picked from commit 12a9f71a9945f3c6c2df87e5bb2a315d09072bf9)
---
 src/IMG_libpng.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/IMG_libpng.c b/src/IMG_libpng.c
index f90c9b14..c8102663 100644
--- a/src/IMG_libpng.c
+++ b/src/IMG_libpng.c
@@ -1274,7 +1274,7 @@ bool IMG_CreateAPNGAnimationDecoder(IMG_AnimationDecoder *decoder, SDL_Propertie
     while (!found_iend) {
         char chunk_type[5] = { 0 };
         png_bytep chunk = NULL;
-        Uint32 chunk_size;
+        Uint32 chunk_size = 0;
         png_bytep chunk_data = NULL;
         Uint32 chunk_length = 0;
         bool chunk_saved = false;