Bug 204197 – Turn off antialiasing when rendering with Ahem, for testing

• Status: RESOLVED
• Resolution: FIXED
• Component: Text

[Simon Fraser (smfr)]

We should add a setting to allow Ahem antialiasing to be turned off when running tests.

This is necessary to match the behavior of other browsers when running web platform tests.

[Radar WebKit Bug Importer]

<rdar://problem/57190712>

[Simon Fraser (smfr)]

Created attachment 383896 [details]
Patch

[Simon Fraser (smfr)]

Created attachment 383919 [details]
Patch

[EWS Watchlist]

Comment on attachment 383919 [details]
Patch

Attachment 383919 [details] did not pass win-ews (win):
Output: https://webkit-queues.webkit.org/results/13268555

New failing tests:
imported/blink/fast/events/panScroll-crash.html

[EWS Watchlist]

Created attachment 383945 [details]
Archive of layout-test-results from ews213 for win-future

The attached test failures were seen while running run-webkit-tests on the win-ews.
Bot: ews213  Port: win-future  Platform: CYGWIN_NT-10.0-17763-3.0.5-338.x86_64-x86_64-64bit

[EWS Watchlist]

Comment on attachment 383896 [details]
Patch

Attachment 383896 [details] did not pass win-ews (win):
Output: https://webkit-queues.webkit.org/results/13268806

New failing tests:
fast/dom/domTokenListIterator.html
fast/dom/nodeListIterator.html
fast/dom/NodeList/nodelist-iterable.html

[EWS Watchlist]

Created attachment 383953 [details]
Archive of layout-test-results from ews214 for win-future

The attached test failures were seen while running run-webkit-tests on the win-ews.
Bot: ews214  Port: win-future  Platform: CYGWIN_NT-10.0-17763-3.0.5-338.x86_64-x86_64-64bit

[Simon Fraser (smfr)]

*** Bug 203750 has been marked as a duplicate of this bug. ***

[WebKit Commit Bot]

Comment on attachment 383919 [details]
Patch

Clearing flags on attachment: 383919

Committed r252701: <https://trac.webkit.org/changeset/252701>

[Aakash Jain]

> Committed r252701: <https://trac.webkit.org/changeset/252701>
Some tests whose TestExpectations were updated in this commit are still failing on iOS. See Bug 204505.

[Sam Sneddon [:gsnedders]]

See also Bug 17086 for earlier discussion about this (with regards to earlier versions of Acid 3), and disagreement between Hixie and Hyatt as to whether disabling Ahem AA makes sense.

[Myles C. Maxfield]

(In reply to Sam Sneddon [:gsnedders] from comment #11)
> See also Bug 17086 for earlier discussion about this (with regards to
> earlier versions of Acid 3), and disagreement between Hixie and Hyatt as to
> whether disabling Ahem AA makes sense.

I disagree with Hixie's comment in https://bugs.webkit.org/show_bug.cgi?id=17086#c13. Platform antialiasing is complicated, using advanced signal analysis techniques. The result of antialiasing is not always intuitive.