From 4478bc8d2bc63c98fa87b26e19b3b4a42fcffa8f Mon Sep 17 00:00:00 2001
From: Albert Astals Cid <aacid@kde.org>
Date: Wed, 24 Jul 2024 23:38:51 +0200
Subject: [PATCH] xcf: Fix crash on broken files

---
 src/imageformats/xcf.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/imageformats/xcf.cpp b/src/imageformats/xcf.cpp
index b2fb773..6611d9a 100644
--- a/src/imageformats/xcf.cpp
+++ b/src/imageformats/xcf.cpp
@@ -1672,8 +1672,12 @@ bool XCFImageFormat::assignImageBytes(Layer &layer, uint i, uint j, const GimpPr
         for (int y = 0; y < height; y++) {
             uchar *dataPtr = bits + y * bytesPerLine;
             uchar *alphaPtr = nullptr;
-            if (!layer.alpha_tiles.isEmpty())
-                alphaPtr = layer.alpha_tiles[j][i].scanLine(y);
+            if (!layer.alpha_tiles.isEmpty()) {
+                QImage &alphaTile = layer.alpha_tiles[j][i];
+                if (alphaTile.width() >= width && alphaTile.height() > y) {
+                    alphaPtr = alphaTile.scanLine(y);
+                }
+            }
             if (bpc == 4) {
 #ifdef USE_FLOAT_IMAGES
                 if (precision < GimpPrecision::GIMP_PRECISION_HALF_LINEAR) {