wayland: Fix memleaks when rendering with Cairo

We were leaking buffers. This wasn't caught by valgrind and friends
because it was shared memory (with the compositor), but top(1) would
instantly see memory consumption of the app and the shell go through the
roof.

diff --git a/gdk/wayland/gdkcairocontext-wayland.c b/gdk/wayland/gdkcairocontext-wayland.c
index fcc547ecf600453f78d94f96e4e74d5c96ff367c..819daa140e3ae2527055e9dceff8a1dc6804cef3 100644 (file)
--- a/gdk/wayland/gdkcairocontext-wayland.c
+++ b/gdk/wayland/gdkcairocontext-wayland.c
@@ -109,6 +109,8 @@ gdk_wayland_cairo_context_buffer_release (void             *_data,
 
   /* Get rid of all the extra ones */
   gdk_wayland_cairo_context_remove_surface (self, cairo_surface);
+  /* Release the reference the compositor held to this surface */
+  cairo_surface_destroy (cairo_surface);
 }
 
 static const struct wl_buffer_listener buffer_listener = {
@@ -194,7 +196,7 @@ gdk_wayland_cairo_context_end_frame (GdkDrawContext *draw_context,
 static void
 gdk_wayland_cairo_context_clear_all_cairo_surfaces (GdkWaylandCairoContext *self)
 {
-  self->cached_surface = NULL;
+  g_clear_pointer (&self->cached_surface, cairo_surface_destroy);
   while (self->surfaces)
     gdk_wayland_cairo_context_remove_surface (self, self->surfaces->data);
 }
@@ -221,6 +223,8 @@ gdk_wayland_cairo_context_dispose (GObject *object)
   GdkWaylandCairoContext *self = GDK_WAYLAND_CAIRO_CONTEXT (object);
 
   gdk_wayland_cairo_context_clear_all_cairo_surfaces (self);
+  g_assert (self->cached_surface == NULL);
+  g_assert (self->paint_surface == NULL);
 
   G_OBJECT_CLASS (gdk_wayland_cairo_context_parent_class)->dispose (object);
 }