Bug 216018

Summary: [CG] REGRESSION (Big Sur): A GIF image with a finite loopCount loops an extra cycle
Product: WebKit Reporter: Said Abou-Hallawa <sabouhallawa>
Component: ImagesAssignee: Said Abou-Hallawa <sabouhallawa>
Status: RESOLVED FIXED    
Severity: Normal CC: benjamin, cdumez, cmarcelo, ews-watchlist, simon.fraser, thorton, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Patch
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Patch
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Patch
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Said Abou-Hallawa
Reported 2020-08-31 16:41:44 PDT
If the loopCount key/value is present in the GIF Netscape Looping Application Extension, this means loopCount = value + 1. WebKit has been doing this math for long time. Recently the underlying frameworks in macOS and iOS took care of this extra one. All we need is to adopt the new behavior but also to be backward compatible with old versions of macOS and iOS.
Attachments
Patch (6.73 KB, patch)
2020-08-31 16:56 PDT, Said Abou-Hallawa 		no flags
DetailsFormatted DiffDiff
Patch (6.80 KB, patch)
2020-08-31 16:58 PDT, Said Abou-Hallawa 		no flags
DetailsFormatted DiffDiff
Patch (6.64 KB, patch)
2020-09-01 16:04 PDT, Said Abou-Hallawa 		no flags
DetailsFormatted DiffDiff
Patch (8.16 KB, patch)
2020-09-10 01:09 PDT, Said Abou-Hallawa 		no flags
DetailsFormatted DiffDiff
Show Obsolete (3) View All Add attachment proposed patch, testcase, etc.
Said Abou-Hallawa
Comment 1 2020-08-31 16:56:57 PDT
Created attachment 407637 [details] Patch
Said Abou-Hallawa
Comment 2 2020-08-31 16:58:45 PDT
Created attachment 407638 [details] Patch
Said Abou-Hallawa
Comment 3 2020-08-31 16:59:21 PDT
<rdar://problem/66660579>
Alexey Proskuryakov
Comment 4 2020-08-31 18:40:35 PDT
Comment on attachment 407638 [details] Patch Can this behavior be tested?
Said Abou-Hallawa
Comment 5 2020-08-31 18:47:14 PDT
It is tested by fast/images/animated-gif-loop-count.html. Having the EWS passed this test, means the backward-compatible code path is tested on macOS Catalina. I ran this test manually on macOS Big Sur, and it passed as well.
Said Abou-Hallawa
Comment 6 2020-09-01 16:04:38 PDT
Created attachment 407717 [details] Patch
EWS
Comment 7 2020-09-01 20:13:33 PDT
Committed r266449: <https://trac.webkit.org/changeset/266449> All reviewed patches have been landed. Closing bug and clearing flags on attachment 407717 [details].
Said Abou-Hallawa
Comment 8 2020-09-02 01:04:58 PDT
Reverted r266449 for reason: Underlying frameworks do not work correctly for loopCount >= 1. Committed r266452: <https://trac.webkit.org/changeset/266452>
Said Abou-Hallawa
Comment 9 2020-09-03 15:10:59 PDT
<rdar://problem/68304035>
Said Abou-Hallawa
Comment 10 2020-09-10 01:09:44 PDT
Created attachment 408420 [details] Patch
EWS
Comment 11 2020-09-10 08:57:58 PDT
Committed r266827: <https://trac.webkit.org/changeset/266827> All reviewed patches have been landed. Closing bug and clearing flags on attachment 408420 [details].
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