pango_context_set_matrix() with non-uniform scaling produces wrong metrics
Calling pango_context_set_matrix() with a matrix for horizontally compressed text, so xx < yy (xy and yx being zero), should return about the same metrics as a matrix where xx == yy or identity, except for hinting. Actually the result of pango_layout_line_get_extents() is expanded horizontally, and the geometry.width values as well. It is as if the coordinates are returned in a mix of user and device space.