Fix a failure in the U64 optimized argb path.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@10631 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 1 insertions, 1 deletions

diff --git a/src/fl_draw_image.cxx b/src/fl_draw_image.cxx
index 2562e473e..8c17f010f 100644
--- a/src/fl_draw_image.cxx
+++ b/src/fl_draw_image.cxx
@@ -317,7 +317,7 @@ static void xrgb_converter(const uchar *from, uchar *to, int w, int delta) {
 }
 
 static void argb_premul_converter(const uchar *from, uchar *to, int w, int delta) {
-  INNARDS32((from[3] << 24) +
+  INNARDS32((unsigned(from[3]) << 24) +
              (((from[0] * from[3]) / 255) << 16) +
              (((from[1] * from[3]) / 255) << 8) +
              ((from[2] * from[3]) / 255));