Fix corrupted titlebar icons in subwindows of ARGB applications

src/kernel/qwidget_x11.cpp

@@ -44,6 +44,7 @@
 #include "qpaintdevicemetrics.h"
 #include "qpainter.h"
 #include "qbitmap.h"
+#include "qimage.h"
 #include "qobjectlist.h"
 #include "qlayout.h"
 #include "qtextcodec.h"
@@ -1310,14 +1311,47 @@ void QWidget::setIcon( const QPixmap &pixmap )
     }
     Pixmap icon_pixmap = 0;
     Pixmap mask_pixmap = 0;
+    QPixmap* pm = NULL;
     if ( !pixmap.isNull() ) {
-	QPixmap* pm = new QPixmap( pixmap );
+	if (pixmap.depth() == 24) {
+	    pm = new QPixmap( pixmap );
+	}
+	else {
+	    // With most window managers, only 24-bit icon pixmaps are allowed in the WM hints, otherwise corrupt icons will be displayed
+	    // Convert provided pixmaps to 24-bit here
+	    int w = pixmap.width();
+	    int h = pixmap.height();
+	    pm = new QPixmap( pixmap.width(), pixmap.height(), 24 );
+	    QImage iconImage = pixmap.convertToImage();
+
+	    // Load the new 24-bit RGB pixmap with data
+	    GC gc;
+	    pm->detach();
+	    Qt::HANDLE pmHandle = pm->handle();
+	    gc = XCreateGC(x11Display(), pmHandle, 0, 0);
+	    for (int y = 0; y < h; ++y) {
+		QRgb *ls = (QRgb *)iconImage.scanLine( y );
+		for (int x = 0; x < w; ++x) {
+		    QRgb l = ls[x];
+		    int r = int( qRed( l ) );
+		    int g = int( qGreen( l ) );
+		    int b = int( qBlue( l ) );
+		    ls[x] = qRgb( r, g, b );
+		    XSetForeground(x11Display(), gc, (r << 16) | (g << 8) | b );
+		    XDrawPoint(x11Display(), pmHandle, gc, x, y);
+		}
+	    }
+	    XFreeGC(x11Display(), gc);
+	}
+
 	extra->topextra->icon = pm;
-	if ( !pm->mask() )
+	if ( !pm->mask() ) {
 	    pm->setMask( pm->createHeuristicMask() ); // may do detach()
+	}
 	icon_pixmap = pm->handle();
-	if ( pm->mask() )
+	if ( pm->mask() ) {
 	    mask_pixmap = pm->mask()->handle();
+	}
     }
     XWMHints *h = XGetWMHints( x11Display(), winId() );
     XWMHints  wm_hints;