shaped-texture: Fix damage propagation for rotated transforms with viewport
When a viewport source rect or destination size is set, stex->dst_width
gives us the the cropped and/or scaled size. At this step, we need the
uncropped/unscaled size however.
Note: this is only ever relevant if buffer transform and viewport are used together - otherwise the values are the same.
How to test:
- For once the new in-development Firefox backend (https://bugzilla.mozilla.org/show_bug.cgi?id=1699985), which behaves like Weston with this patch
- For the rotated cases:
- Apply !1055 (merged)
- change the
weston-simple-damage
client: comment out thewp_viewport_set_source
line - run it with e.g.
weston-simple-damage --use-viewport --use-damage-buffer --transform=90