src/share/classes/com/sun/imageio/plugins/gif/GIFImageReader.java

@@ -772,20 +772,16 @@
         System.arraycopy(src, offset, dst, 0, len);
         return offset + len;
     }
 
     private void startPass(int pass) {
-        if (updateListeners == null) {
+        if (updateListeners == null || !imageMetadata.interlaceFlag) {
             return;
         }
 
-        int y = 0;
-        int yStep = 1;
-        if (imageMetadata.interlaceFlag) {
-            y = interlaceOffset[interlacePass];
-            yStep = interlaceIncrement[interlacePass];
-        }
+        int y = interlaceOffset[interlacePass];
+        int yStep = interlaceIncrement[interlacePass];
 
         int[] vals = ReaderUtil.
             computeUpdatedPixels(sourceRegion,
                                  destinationOffset,
                                  destinationRegion.x,