Bug 226006 - REGRESSION: Safari v14.1 computes element height to be 33,554,432 pixels
Summary: REGRESSION: Safari v14.1 computes element height to be 33,554,432 pixels
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: Layout and Rendering (show other bugs)
Version: Safari 14
Hardware: Mac (Intel) macOS 11
: P2 Normal
Assignee: zalan
URL: https://jsfiddle.net/ao1xcs2q/
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2021-05-19 23:08 PDT by MarkG
Modified: 2021-05-26 06:28 PDT (History)
5 users (show)

See Also:

Attachments
screenshot of how jsfiddle looks in safari v14.1 vs how it should actually look (16.44 KB, image/png)
2021-05-19 23:08 PDT, MarkG 		no flags Details
Test reduction (312 bytes, text/html)
2021-05-25 11:13 PDT, zalan 		no flags Details
Patch (6.83 KB, patch)
2021-05-25 16:16 PDT, zalan 		no flags Details | Formatted Diff | Diff
View All Add an attachment (proposed patch, testcase, etc.)

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Description MarkG 2021-05-19 23:08:19 PDT 
Created attachment 429138 [details]
screenshot of how jsfiddle looks in safari v14.1 vs how it should actually look

Safari v14.1 (build 16611.1.21.161.6) broke the display of one of our pages. I've replicated the problem here: https://jsfiddle.net/ao1xcs2q/ I have also attached a screenshot which shows how the jsfiddle renders on safari v14.1 (and iOS v14.5.1) and how it used to render on previous versions.

The element that breaks rendering is: <small class="noteshow">This could be a YouTube or Vimeo video, or something else</small>. The css rule that causes the problem is the margin-top: -10px. Safari v14.1 renders the element as 33,554,432 pixels high, completely obscuring any following content on the page. Disabling this rule makes makes the element render as expected.
Comment 1 Alexey Proskuryakov 2021-05-21 16:38:18 PDT 
I can reproduce with r277884.
Comment 2 zalan 2021-05-25 11:13:44 PDT 
Created attachment 429667 [details]
Test reduction
Comment 3 Radar WebKit Bug Importer 2021-05-25 12:44:25 PDT 
<rdar://problem/78471122>
Comment 4 Radar WebKit Bug Importer 2021-05-25 14:22:59 PDT 
<rdar://problem/78476119>
Comment 5 zalan 2021-05-25 16:16:01 PDT 
Created attachment 429707 [details]
Patch
Comment 6 EWS 2021-05-26 06:28:09 PDT 
Committed r278080 (238159@main): <https://commits.webkit.org/238159@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 429707 [details].