fixed crash bug when accessing invalid change page for broken level files

Thanks to Quipyowert for finding and fixing this bug!

diff --git a/src/files.c b/src/files.c
index 09e3b4d2256fcfe7d7cee4b6c655070f57aee90b..45f4097f85f734dcb3645116b2bd616285a48726 100644 (file)
--- a/src/files.c
+++ b/src/files.c
@@ -3355,6 +3355,10 @@ static int LoadLevel_CUSX(File *file, int chunk_size, struct LevelInfo *level)
 
   while (!checkEndOfFile(file))
   {
+    // level file might contain invalid change page number
+    if (xx_current_change_page >= ei->num_change_pages)
+      break;
+
     struct ElementChangeInfo *change = &ei->change_page[xx_current_change_page];
 
     xx_change = *change;       // copy change data into temporary buffer