User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/534.36 (KHTML, like Gecko) Chrome/13.0.767.1 Safari/534.36 Build Identifier: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:6.0a1) Gecko/20110523 Firefox/6.0a1 Code snippet: c.globalCompositeOperation = "source-over"; c.fillStyle="blue"; c.fillRect(0, 0, 100, 100); c.globalCompositeOperation = "destination-in"; c.scale(0, 0); c.fillStyle = "red"; c.fillRect(10, 30, 20, 20); See URL for demo. The second fillRect() call is made with a scale to 0, 0 and should result in the shape being transformed to a 0-width, 0-height rectangle. The composite step should then draw a 0, 0 sized rectangle into an infinite large black bitmap (which is a no-op) and then apply the composite operation for destination-in to the whole canvas, clearing it. I suspect that the draw is being ignored completely since the CTM is not invertible, but that's not a safe optimization when the globalCompositeOperation is destination-in. Opera 10.62 on my box does clear the entire canvas and I just reviewed a patch to WebKit to do the same (assuming that it doesn't have bugs). Reproducible: Always
Status: UNCONFIRMED → NEW
Ever confirmed: true
Nice bug :-)
Whiteboard: [good first bug]
In Firefox, I see a blank canvas, while in Chrome, I see a blue square (from the link). Which is the expected behavior? From the description, I believe FF may have already fixed this.
Whiteboard: [good first bug] → [good first bug][exterminationweek]
Whiteboard: [good first bug][exterminationweek] → [good first bug]
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