* generic/tkImgBmap.c (ImgBmapConfigureInstance): If an image

mask changed but ended up with the same XID, the GC failed to be
updated and so the new mask was not used. [Bug: 970]

1 files changed, 13 insertions, 5 deletions

diff --git a/generic/tkImgBmap.c b/generic/tkImgBmap.c
index d3e9f41..d7be9de 100644
--- a/generic/tkImgBmap.c
+++ b/generic/tkImgBmap.c
@@ -9,7 +9,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tkImgBmap.c,v 1.4 1998/09/14 18:23:12 stanton Exp $
+ * RCS: @(#) $Id: tkImgBmap.c,v 1.5 1999/02/04 20:56:15 stanton Exp $
  */
 
 #include "tkInt.h"
@@ -340,6 +340,7 @@ ImgBmapConfigureInstance(instancePtr)
     XGCValues gcValues;
     GC gc;
     unsigned int mask;
+    Pixmap oldMask;
 
     /*
      * For each of the options in masterPtr, translate the string
@@ -382,10 +383,14 @@ ImgBmapConfigureInstance(instancePtr)
 		(unsigned) masterPtr->height);
     }
 
-    if (instancePtr->mask != None) {
-	Tk_FreePixmap(Tk_Display(instancePtr->tkwin), instancePtr->mask);
-	instancePtr->mask = None;
-    }
+    /*
+     * Careful:  We have to allocate a new mask Pixmap before deleting
+     * the old one.  Otherwise, The XID allocator will always return
+     * the same XID for the new Pixmap as was used for the old Pixmap.
+     * And that will prevent the mask from changing in the GC below.
+     */
+    oldMask = instancePtr->mask;
+    instancePtr->mask = None;
     if (masterPtr->maskData != NULL) {
 	instancePtr->mask = XCreateBitmapFromData(
 		Tk_Display(instancePtr->tkwin),
@@ -393,6 +398,9 @@ ImgBmapConfigureInstance(instancePtr)
 		masterPtr->maskData, (unsigned) masterPtr->width,
 		(unsigned) masterPtr->height);
     }
+    if (oldMask != None) {
+      Tk_FreePixmap(Tk_Display(instancePtr->tkwin), oldMask);
+    }
 
     if (masterPtr->data != NULL) {
 	gcValues.foreground = instancePtr->fg->pixel;