[cairo] Change of _cairo_meta_surface_get_extents

[Emmanuel Pacaud]

Hi,

Last push_group related tests added to testsuite trig a nasty behaviour
in SVG backend.

Currently, this backend returns a meta-surface on a call to
create_similar. And push_group uses a call to get_extents when creating
the subsurface it needs.

But meta_surface::get_extents returns CAIRO_MAXSHORT for height and
width.

So, when using push_group in a surface created via create_similar from a
SVG surface, the resulting subsurface has a size of
CAIRO_MAXSHORT*CAIRO_MAXSHORT.

Which is not good, especially when this subsurface is rendered via image
fallback (a CAIRO_MAXSHORT*CAIRO_MAXSHORT image is huge, isn't it ?).

Here's a quick fix for this issue:

diff --git a/src/cairo-meta-surface.c b/src/cairo-meta-surface.c
index 9a8ce7b..5436328 100644
--- a/src/cairo-meta-surface.c
+++ b/src/cairo-meta-surface.c
@@ -547,10 +547,12 @@ static cairo_int_status_t
 _cairo_meta_surface_get_extents (void
*abstract_surface,
                                 cairo_rectangle_fixed_t *rectangle)
 {
+    cairo_meta_surface_t *meta = abstract_surface;
+
     rectangle->x = 0;
     rectangle->y = 0;
-    rectangle->width = CAIRO_MAXSHORT;
-    rectangle->height = CAIRO_MAXSHORT;
+    rectangle->width = meta->width_pixels;
+    rectangle->height = meta->height_pixels;

     return CAIRO_STATUS_SUCCESS;
 }

If I've understood correctly the purpose of get_extents, it's not the
right fix. But I'm not sure any backend implements get_extents the way
it should.

Ok to push ?

	Emmanuel.