qt-bugs@ issue : None
Trolltech task ID : None
bugs.kde.org number : None
applied: no
author: Fredrik Höglund <fredrik@kde.org>

Since there's no way to specify that a QPixmap should have an alpha channel
when it's created, it's quite common to call pixmap.fill(Qt::transparent)
immediately after creating it, to force Qt to recreate it with an alpha
channel. Unfortunately QPixmap::fill() does this by creating a QImage,
filling it with the specified color, and then converting it to a QPixmap.

This patch avoids the expensive image->pixmap conversion by simply discarding
the old pixmap, creating a new one with the correct format, and doing the
fill server side.

--- a/src/gui/image/qpixmap_x11.cpp
+++ b/src/gui/image/qpixmap_x11.cpp
@@ -1107,7 +1107,26 @@
 {
     if (fillColor.alpha() != 255) {
 #ifndef QT_NO_XRENDER
-        if (picture && d == 32) {
+        if (X11->use_xrender) {
+            if (!picture || d != 32) {
+                if (picture)
+                    XRenderFreePicture(X11->display, picture);
+                if (mask_picture)
+                    XRenderFreePicture(X11->display, mask_picture);
+                if (x11_mask)
+                    XFreePixmap(X11->display, x11_mask);
+                if (hd)
+                    XFreePixmap(X11->display, hd);
+                if (hd2)
+                    XFreePixmap(X11->display, hd2);
+                XRenderPictFormat *format = XRenderFindStandardFormat(X11->display, PictStandardARGB32);
+                hd = XCreatePixmap(X11->display, RootWindow(X11->display, xinfo.screen()), width(), height(), 32);
+                picture = XRenderCreatePicture(X11->display, hd, format, 0, 0);
+                mask_picture = 0;
+                x11_mask = 0;
+                hd2 = 0;
+                d = 32;
+            }
             ::Picture src  = X11->getSolidFill(xinfo.screen(), fillColor);
             XRenderComposite(X11->display, PictOpSrc, src, 0, picture,
                              0, 0, width(), height(),