Bug 27116

Summary: CSS3 Multicolumn box occasionally gets taller
Product: WebKit Reporter: Yuta Kitamura <yutak>
Component: CSSAssignee: Nobody <webkit-unassigned>
Status: UNCONFIRMED ---    
Severity: Normal CC: ahmad.saleem792, ap, osvaldo.rivera1994, pemrichm, simon.fraser, svillar, zalan
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: PC   
OS: OS X 10.5   
Attachments:
Description Flags
Test case
none
Screenshot
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Demonstration of why it doesn't appear to be solely a columnar rendering issue. none

Description Yuta Kitamura 2009-07-09 06:19:05 PDT
Created attachment 32515 [details]
Test case

CSS3 Multicolumn box occasionally becomes taller than the size of the children.

WebKit trunk renders the attached test case wrongly. The second block is taller than the other blocks, while all the blocks should have the same height.
Comment 1 Yuta Kitamura 2009-07-09 06:20:46 PDT
Created attachment 32516 [details]
Screenshot
Comment 2 Yuta Kitamura 2009-07-10 05:12:08 PDT
See section 7 of CSS3 Multi-column spec.
http://www.w3.org/TR/2009/WD-css3-multicol-20090630/#filling-columns
Comment 3 Sabri Aurrelia 2011-05-19 08:43:49 PDT
This isn't an occasional or random thing.  It can be reproduced with some regularity.  I don't think this is a problem with columns per se, but something that webkit's implementation of columns draws more attention to.  It really appears to be a font rendering issue.  After twiddling the code, I notice that rendering of certain fonts magnifies the issue most.
Comment 4 Sabri Aurrelia 2011-05-19 08:45:41 PDT
Created attachment 94074 [details]
Demonstration of why it doesn't appear to be solely a columnar rendering issue.
Comment 5 Ahmad Saleem 2022-06-02 21:20:28 PDT
I am still able to reproduce this issue in Safari 15.5 on macOS 12.4 using attached "test case" and output matches the original screenshot from 2009.

For other browser, Chrome Canary 104 and Firefox Nightly 103 also have different behavior on attached test case from Safari and each other.

I am not sure, which browser is rendering this correctly. Thanks!