I just found out why PNG decoding was broken in SqueakJS [*]. Wouldn't have believed that any code actually relied on the following behavior:

	| a |
	a := (1 to: 20) asArray.
	a replaceFrom: 11 to: 20 with: a startingAt: 8.

	==> #(1 2 3 4 5 6 7 8 9 10 8 9 10 8 9 10 8 9 10 8)

In my (buggy) VM it answered

	==> #(1 2 3 4 5 6 7 8 9 10 8 9 10 11 12 13 14 15 16 17)

which apparently did not at all match what The Creators intended ;)

- Bert -

[*] specifically, #decompressBlock:with:
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