From 6950b233e41a0c926465728c37f9bc5512f2844b Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 15 Jan 2010 14:25:16 +0000
Subject: [PATCH] qt: Make flush() robust.

Hanno Meyer-Thurow reported in

  http://bugs.freedesktop.org/show_bug.cgi?id=26063
  [PATCH] various fixes to cairo-qt

a few issues related to _cairo_qt_surface_flush() where firefox was
crashing after being built to use cairo-qt.

This is an amalgam of those patches that hopefully address the issue.
---
 src/cairo-qt-surface.cpp | 33 ++++++++++++++++++++++++++-------
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/src/cairo-qt-surface.cpp b/src/cairo-qt-surface.cpp
index 902251d31..29ca0be0a 100644
--- a/src/cairo-qt-surface.cpp
+++ b/src/cairo-qt-surface.cpp
@@ -485,7 +485,7 @@ _cairo_qt_surface_finish (void *abstract_surface)
     if (qs->image || qs->pixmap)
         delete qs->p;
     else
-        qs->p->restore();
+	qs->p->restore ();
 
     if (qs->image_equiv)
         cairo_surface_destroy (qs->image_equiv);
@@ -1553,11 +1553,30 @@ static cairo_status_t
 _cairo_qt_surface_flush (void *abstract_surface)
 {
     cairo_qt_surface_t *qs = (cairo_qt_surface_t *) abstract_surface;
-    
-    QPaintDevice * dev = qs->p->device();
-    qs->p->end();
-    qs->p->begin(dev);
-    
+
+    if (qs->p == NULL)
+	return CAIRO_STATUS_SUCCESS;
+
+    if (qs->image || qs->pixmap) {
+	qs->p->end ();
+	qs->p->begin (qs->p->device ());
+    } else {
+	qs->p->restore ();
+    }
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+static cairo_status_t
+_cairo_qt_surface_mark_dirty (void *abstract_surface,
+			      int x, int y,
+			      int width, int height)
+{
+    cairo_qt_surface_t *qs = (cairo_qt_surface_t *) abstract_surface;
+
+    if (qs->p && !(qs->image || qs->pixmap))
+	qs->p->save ();
+
     return CAIRO_STATUS_SUCCESS;
 }
 
@@ -1586,7 +1605,7 @@ static const cairo_surface_backend_t cairo_qt_surface_backend = {
     NULL, /* old_show_glyphs */
     NULL, /* get_font_options */
     _cairo_qt_surface_flush,
-    NULL, /* mark_dirty_rectangle */
+    _cairo_qt_surface_mark_dirty,
     NULL, /* scaled_font_fini */
     NULL, /* scaled_glyph_fini */