* Audit: text layout, shaping, fonts and embedding bounds
* Audit: text bitmap chunk walk without overflow
* Test: PNG metadata chunk walk
* Security: keep the word minimum in wrap regions; allow uncompressed iTXt text
A wrap shape can narrow the first baseline of a rectangular region:
place_at_least then relaxed the minimum to 0 (the region still counted as
"all lines equally wide") and picked the narrow span, breaking a word on
that baseline even though a lower one had room for it whole. Treat the
width as constant only when the region has no wrap shapes.
Also, PNG iTXt chunks may be stored uncompressed: only genuinely
compressed text (flag 1, conservatively anything that does not parse)
counts as compressed metadata now.
Dylan M. Taylor
d1288e3019