The -coalesce option requires a transparent background

diff --git a/MagickCore/layer.c b/MagickCore/layer.c
index 737cee95988d92d5b6c4a98237ef6e046ad3c1e0..7ddfca7af3a5cffdca0322add8a4610f4c767244 100644 (file)
--- a/MagickCore/layer.c
+++ b/MagickCore/layer.c
@@ -268,6 +268,7 @@ MagickExport Image *CoalesceImages(const Image *image,ExceptionInfo *exception)
     exception);
   if (coalesce_image == (Image *) NULL)
     return((Image *) NULL);
+  coalesce_image->background_color.alpha=(Quantum) TransparentAlpha;
   (void) SetImageBackgroundColor(coalesce_image,exception);
   coalesce_image->alpha_trait=next->alpha_trait;
   coalesce_image->page=bounds;