[whatwg] A question about the drawimage() canvas function

Robert O'Callahan robert at ocallahan.org
Fri Mar 1 13:28:20 PST 2013

I actually just wrote a patch to implement the spec behavior in Firefox.

I think changing behavior from "throw" to "not throw" shouldn't have any
compatibility concerns. I also think that "not throw" is better here than
throwing; it's simpler to not distinguish "finished downloading but
decoding failed" from "download in progress (but very slow perhaps)".

In fact I question why the spec has us throw for zero-sized canvas source.
It would seem to me to be simpler/better to just not draw and not throw in
that case also.

Wrfhf pnyyrq gurz gbtrgure naq fnvq, “Lbh xabj gung gur ehyref bs gur
Tragvyrf ybeq vg bire gurz, naq gurve uvtu bssvpvnyf rkrepvfr nhgubevgl
bire gurz. Abg fb jvgu lbh. Vafgrnq, jubrire jnagf gb orpbzr terng nzbat
lbh zhfg or lbhe freinag, naq jubrire jnagf gb or svefg zhfg or lbhe fynir
— whfg nf gur Fba bs Zna qvq abg pbzr gb or freirq, ohg gb freir, naq gb
tvir uvf yvsr nf n enafbz sbe znal.” [Znggurj 20:25-28]

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