tree b0e782fcefe7ddbed1e002f087769549ad59f0ef
parent 1fe71aa315b038315582f74189f3750fc7d94557
author wenson_hsieh@apple.com <wenson_hsieh@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1563245482 +0000
committer wenson_hsieh@apple.com <wenson_hsieh@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1563245482 +0000

[Text autosizing] [iPadOS] Product label text is clipped in portrait mode on the front page of sephora.com
https://bugs.webkit.org/show_bug.cgi?id=199806
<rdar://problem/52902482>

Reviewed by Zalan Bujtas.

Source/WebCore:

On sephora.com, some product label text is currently boosted by idempotent text autosizing, which causes the
labels be vertically clipped. This patch augments the idempotent text autosizing heuristic to avoid this case by
checking if the element to be boosted has a fixed height or max height, whose value is very close to a small
integer multiple of the line height. In this case, it's likely that the website expects the text to be no more
than a few lines' worth of height, so boosting the text is likely to break the page.

Test: fast/text-autosizing/ios/idempotentmode/idempotent-autosizing-candidates.html

* rendering/style/RenderStyle.cpp:
(WebCore::RenderStyle::isIdempotentTextAutosizingCandidate const):
* rendering/style/TextSizeAdjustment.cpp:
(WebCore::AutosizeStatus::updateStatus):
* rendering/style/TextSizeAdjustment.h:

Rename Fields::DisplayNone to Fields::AvoidSubtree to avoid introducing another bit in RenderStyle's inherited
flags.

LayoutTests:

Add a new test case to an existing layout test, which mimics the product label text on sephora.com's front page.

* fast/text-autosizing/ios/idempotentmode/idempotent-autosizing-candidates-expected.txt:
* fast/text-autosizing/ios/idempotentmode/idempotent-autosizing-candidates.html:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@247467 268f45cc-cd09-0410-ab3c-d52691b4dbfc