RESOLVED FIXED 18821
Canvas putImageData incorrect when data has alpha 
https://bugs.webkit.org/show_bug.cgi?id=18821
Summary Canvas putImageData incorrect when data has alpha
Philip Taylor
Reported 2008-04-30 18:31:11 PDT
See test case in URL. It draws a very-transparent red column on the left, then fills the rest of the canvas with slightly-transparent green, then calls putImageData(getImageData(...), ...) which should have no effect. Expected output: alert box saying "0,255,0,254" (or maybe 253), alert box saying "0,255,0,254" (or maybe 253), green canvas. Actual output: alert box saying "0,255,0,253", alert box saying "255,0,0,253", red canvas. Tested on Windows r32574.
Attachments
Fix bugs in the loops of both get and putImageData (3.82 KB, patch)
2008-05-01 11:50 PDT, Dave Hyatt 		hyatt: review-
DetailsFormatted DiffDiff
Fix bugs in the loops of both get and putImageData (2.08 KB, patch)
2008-05-01 11:51 PDT, Dave Hyatt 		eric: review+
DetailsFormatted DiffDiff
Patch to fix the bug (5.11 KB, patch)
2008-05-05 11:19 PDT, Dave Hyatt 		eric: review+
DetailsFormatted DiffDiff
Show Obsolete (2) View All Add attachment proposed patch, testcase, etc.
Dave Hyatt
Comment 1 2008-05-01 11:50:41 PDT
Created attachment 20914 [details] Fix bugs in the loops of both get and putImageData
Dave Hyatt
Comment 2 2008-05-01 11:51:57 PDT
Created attachment 20915 [details] Fix bugs in the loops of both get and putImageData
Eric Seidel (no email)
Comment 3 2008-05-01 19:41:15 PDT
Comment on attachment 20915 [details] Fix bugs in the loops of both get and putImageData Needs a test case and changelog when you land. Otherwise fine.
Dave Hyatt
Comment 4 2008-05-05 11:19:38 PDT
Created attachment 20971 [details] Patch to fix the bug
Eric Seidel (no email)
Comment 5 2008-05-05 11:27:45 PDT
Comment on attachment 20971 [details] Patch to fix the bug Looks saner. Still needs a ChangeLog when landing.
Dave Hyatt
Comment 6 2008-05-05 11:29:58 PDT
Fixed in r32878.
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