surface: Inherit device scale in cairo_surface_create_similar()

Without this most code that uses similar surfaces for offscreen
rendering will render in a pixelized fashion if the final
target uses a device scale.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/cairo-surface.c b/src/cairo-surface.c
index cdd75b82e..f2f2ef61e 100644
--- a/src/cairo-surface.c
+++ b/src/cairo-surface.c
@@ -507,6 +507,10 @@ cairo_surface_create_similar (cairo_surface_t  *other,
         if (unlikely (other->status))
 	return _cairo_surface_create_in_error (other->status);
 
+    /* We inherit the device scale, so create a larger surface */
+    width = width * other->device_transform.xx;
+    height = height * other->device_transform.yy;
+
     surface = NULL;
     if (other->backend->create_similar)
 	surface = other->backend->create_similar (other, content, width, height);
@@ -519,6 +523,9 @@ cairo_surface_create_similar (cairo_surface_t  *other,
 	return surface;
 
     _cairo_surface_copy_similar_properties (surface, other);
+    cairo_surface_set_device_scale (surface,
+				    other->device_transform.xx,
+				    other->device_transform.yy);
 
     if (unlikely (surface->status))
 	return surface;