Bug 262289

Summary: Matched properties cache doesn't account for lh units correctly.
Product: WebKit Reporter: Emilio Cobos Álvarez (:emilio) <emilio>
Component: CSSAssignee: Nobody <webkit-unassigned>
Status: RESOLVED WORKSFORME    
Severity: Normal CC: emilio, karlcow, koivisto, ntim
Priority: P2 Keywords: BrowserCompat
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
See Also: https://bugs.webkit.org/show_bug.cgi?id=260199
Attachments:
Description Flags
rendering in Safari, firefox, chrome none

Description Emilio Cobos Álvarez (:emilio) 2023-09-28 01:45:54 PDT 
What steps will reproduce the problem?

(1) Open https://crisal.io/tmp/lh-sharing.html
(2) See how both blocks are 50px tall, even though the line-height of the second one is 100px.

I caught this while reviewing the Firefox patches to support lh/rlh.

Chromium bug: https://bugs.chromium.org/p/chromium/issues/detail?id=1487480
Comment 1 Karl Dubost 2023-09-28 18:47:00 PDT 
Created attachment 467969 [details]
rendering in Safari, firefox, chrome

Thanks Emilio.
I can not reproduce on STP 179.
Comment 2 Karl Dubost 2023-09-28 18:56:52 PDT 
document.querySelectorAll('div')[2].getBoundingClientRect()

returns 100 in STP 179 and Firefox 120.0a1 (2023-09-28) (64-bit)
and returns 50 in Version 119.0.6036.0 (Official Build) canary (arm64)

So it was probably fixed.
Comment 3 Emilio Cobos Álvarez (:emilio) 2023-09-29 03:28:56 PDT 
I don't see anything from here that deals with line-height, so I'm skeptic that it has been fixed: https://searchfox.org/wubkat/rev/c5cb966bfdbd256be13f3a3c5eafaec9eccb1f0a/Source/WebCore/style/MatchedDeclarationsCache.cpp#61-101
Comment 4 Karl Dubost 2023-09-29 07:09:33 PDT 
Emilio

fwiw the test is not working on Safari 17 released version. 
So this is a recent fix. Let's Autospade

Bug 260199
https://github.com/WebKit/WebKit/commit/b733d192e11b8379df67740799a87cecaa565a85