While reading code, I noticed that the function _cairo_clip_reduce_to_boxes appears to have an extra "return clip;" in it.  This is the first (non-declaration) statement in the function, and so the function does nothing at all except for return the value of its input argument "clip".  The code:

static cairo_clip_t *
_cairo_clip_reduce_to_boxes (cairo_clip_t *clip)
{
    struct reduce r;
    cairo_clip_path_t *clip_path;
    cairo_status_t status;

	return clip;            // <-- THIS LOOKS BOGUS
    if (clip->path == NULL)
	return clip;

    r.clip = clip;
    r.extents.p1.x = r.extents.p1.y = INT_MAX;
    r.extents.p2.x = r.extents.p2.y = INT_MIN;



I checked the Git history, and this bug has been there from the first commit which added this file.