[gimp/gimp-2-6] Make cairo code work with newer cairo backends that actually use caching

[Michael Natterer <mitch src gnome org>]

commit 8deda13e5f9b5611387dcd1724bfdcac83f07255
Author: Michael Natterer <mitch gimp org>
Date:   Mon Jun 28 12:23:31 2010 +0200

    Make cairo code work with newer cairo backends that actually use caching
    
    Call cairo_surface_flush() before reading or writing a surface's
    pixels directly, and use cairo_surface_mark_dirty() after writing
    pixels directly, so we don't read old pixels, and our written pixels
    get actually used.
    (manually cherry-picked from fad6053643482e222e246c2db828182b4f2a8c7f)

 app/widgets/gimpviewrenderer.c         |   12 ++++++++++++
 app/widgets/gimpviewrenderergradient.c |    4 ++++
 app/widgets/gimpviewrendererpalette.c  |    4 ++++
 libgimpwidgets/gimpcairo-utils.c       |    4 ++++
 4 files changed, 24 insertions(+), 0 deletions(-)
---
diff --git a/app/widgets/gimpviewrenderer.c b/app/widgets/gimpviewrenderer.c
index 54bc765..9a91a27 100644
--- a/app/widgets/gimpviewrenderer.c
+++ b/app/widgets/gimpviewrenderer.c
@@ -926,6 +926,16 @@ gimp_view_render_to_surface (TempBuf         *temp_buf,
   g_return_if_fail (temp_buf != NULL);
   g_return_if_fail (surface != NULL);
 
+  /* In rare cases we can get here while GIMP is exiting, handle that
+   * by checking for availability of the buffers
+   */
+  if (! gimp_render_check_buf ||
+      ! gimp_render_empty_buf ||
+      ! gimp_render_white_buf)
+    return;
+
+  cairo_surface_flush (surface);
+
   dest        = cairo_image_surface_get_data (surface);
   dest_stride = cairo_image_surface_get_stride (surface);
 
@@ -1078,6 +1088,8 @@ gimp_view_render_to_surface (TempBuf         *temp_buf,
 
       dest += dest_stride;
     }
+
+  cairo_surface_mark_dirty (surface);
 }
 
 void
diff --git a/app/widgets/gimpviewrenderergradient.c b/app/widgets/gimpviewrenderergradient.c
index 563c04d..368f714 100644
--- a/app/widgets/gimpviewrenderergradient.c
+++ b/app/widgets/gimpviewrenderergradient.c
@@ -189,6 +189,8 @@ gimp_view_renderer_gradient_render (GimpViewRenderer *renderer,
                                                     renderer->width,
                                                     renderer->height);
 
+  cairo_surface_flush (renderer->surface);
+
   dest        = cairo_image_surface_get_data (renderer->surface);
   dest_stride = cairo_image_surface_get_stride (renderer->surface);
 
@@ -197,6 +199,8 @@ gimp_view_renderer_gradient_render (GimpViewRenderer *renderer,
       memcpy (dest, buf, renderer->width * 4);
     }
 
+  cairo_surface_mark_dirty (renderer->surface);
+
   renderer->needs_render = FALSE;
 }
 
diff --git a/app/widgets/gimpviewrendererpalette.c b/app/widgets/gimpviewrendererpalette.c
index 9c9eb8b..eeab3f3 100644
--- a/app/widgets/gimpviewrendererpalette.c
+++ b/app/widgets/gimpviewrendererpalette.c
@@ -139,6 +139,8 @@ gimp_view_renderer_palette_render (GimpViewRenderer *renderer,
                                                     renderer->width,
                                                     renderer->height);
 
+  cairo_surface_flush (renderer->surface);
+
   row = g_new (guchar, renderer->width * 4);
 
   dest        = cairo_image_surface_get_data (renderer->surface);
@@ -202,6 +204,8 @@ gimp_view_renderer_palette_render (GimpViewRenderer *renderer,
 
   g_free (row);
 
+  cairo_surface_mark_dirty (renderer->surface);
+
   renderer->needs_render = FALSE;
 }
 
diff --git a/libgimpwidgets/gimpcairo-utils.c b/libgimpwidgets/gimpcairo-utils.c
index 467c9ce..22cf5cb 100644
--- a/libgimpwidgets/gimpcairo-utils.c
+++ b/libgimpwidgets/gimpcairo-utils.c
@@ -229,6 +229,8 @@ gimp_cairo_surface_create_from_pixbuf (GdkPixbuf *pixbuf)
 
   surface = cairo_image_surface_create (format, width, height);
 
+  cairo_surface_flush (surface);
+
   src         = gdk_pixbuf_get_pixels (pixbuf);
   src_stride  = gdk_pixbuf_get_rowstride (pixbuf);
 
@@ -281,5 +283,7 @@ gimp_cairo_surface_create_from_pixbuf (GdkPixbuf *pixbuf)
       break;
     }
 
+  cairo_surface_mark_dirty (surface);
+
   return surface;
 }