[mutter/wip/rstrode/rhel-8.0.0: 84/117] window-actor: Use actual image size for capture

[Ray Strode <halfline src gnome org>]

commit 3bdfbf97b99a64f1bcc4abbdda4c50afeeb080b4
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Tue Jan 22 10:22:27 2019 +0100

    window-actor: Use actual image size for capture
    
    Previously, the clipping rectangle passed to
    `meta_surface_actor_get_image()` was updated with the actual texture
    size, but recent changes in `meta_shaped_texture_get_image()` now keep
    the caller's clipping rectangle unchanged.
    
    The implementation of `meta_window_actor_capture_into()` was relying on
    the old behavior of updating the passed clipping rectangle, but now that
    it's kept unchanged, the actual clipping rectangle used to copy the data
    is wrong, which causes either a distorded image or worse, a crash of
    mutter.
    
    Use the resulting cairo image size to copy the data instead of the
    clipping rectangle to avoid the issue and get the expected size.
    
    Fixes: https://gitlab.gnome.org/GNOME/mutter/issues/442

 src/compositor/meta-window-actor.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)
---
diff --git a/src/compositor/meta-window-actor.c b/src/compositor/meta-window-actor.c
index 396fef1ff..381d3ea85 100644
--- a/src/compositor/meta-window-actor.c
+++ b/src/compositor/meta-window-actor.c
@@ -2260,36 +2260,38 @@ meta_window_actor_capture_into (MetaScreenCastWindow *screen_cast_window,
 {
   MetaWindowActor *window_actor = META_WINDOW_ACTOR (screen_cast_window);
   cairo_surface_t *image;
-  MetaRectangle clip_rect;
   uint8_t *cr_data;
   int cr_stride;
+  int cr_width;
+  int cr_height;
   int bpp = 4;
 
   if (meta_window_actor_is_destroyed (window_actor))
     return;
 
-  clip_rect = *bounds;
-  image = meta_surface_actor_get_image (window_actor->priv->surface, &clip_rect);
+  image = meta_surface_actor_get_image (window_actor->priv->surface, bounds);
   cr_data = cairo_image_surface_get_data (image);
+  cr_width = cairo_image_surface_get_width (image);
+  cr_height = cairo_image_surface_get_height (image);
   cr_stride = cairo_image_surface_get_stride (image);
 
-  if (clip_rect.width < bounds->width || clip_rect.height < bounds->height)
+  if (cr_width < bounds->width || cr_height < bounds->height)
     {
       uint8_t *src, *dst;
       src = cr_data;
       dst = data;
 
-      for (int i = 0; i < clip_rect.height; i++)
+      for (int i = 0; i < cr_height; i++)
         {
           memcpy (dst, src, cr_stride);
-          if (clip_rect.width < bounds->width)
+          if (cr_width < bounds->width)
             memset (dst + cr_stride, 0, (bounds->width * bpp) - cr_stride);
 
           src += cr_stride;
           dst += bounds->width * bpp;
         }
 
-      for (int i = clip_rect.height; i < bounds->height; i++)
+      for (int i = cr_height; i < bounds->height; i++)
         {
           memset (dst, 0, bounds->width * bpp);
           dst += bounds->width * bpp;
@@ -2297,7 +2299,7 @@ meta_window_actor_capture_into (MetaScreenCastWindow *screen_cast_window,
     }
   else
     {
-      memcpy (data, cr_data, clip_rect.height * cr_stride);
+      memcpy (data, cr_data, cr_height * cr_stride);
     }
 
   cairo_surface_destroy (image);