https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=7016

diff --git a/coders/wpg.c b/coders/wpg.c
index b918481549eebd1bf390d29478150690bbb3885f..d453f6f6af4e37c7626ed7d18af84d5f2424ab12 100644 (file)
--- a/coders/wpg.c
+++ b/coders/wpg.c
@@ -1210,7 +1210,7 @@ static Image *ReadWPGImage(const ImageInfo *image_info,
                         sizeof(*image->colormap));
                 }
 
-              if (bpp == 1)
+              if ((bpp == 1) && (image->colors > 1))
                 {
                   if(image->colormap[0].red==0 &&
                      image->colormap[0].green==0 &&