Bug 63385 - Incorrect column breaks? (CSS3 columns)
Summary: Incorrect column breaks? (CSS3 columns)
Status: RESOLVED WORKSFORME
Alias: None
Product: WebKit
Classification: Unclassified
Component: CSS (show other bugs)
Version: 528+ (Nightly build)
Hardware: Mac Unspecified
: P2 Normal
Assignee: Nobody
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2011-06-25 12:57 PDT by Julian Tibble
Modified: 2011-10-05 20:27 PDT (History)
2 users (show)

See Also:


Attachments
HTML file showing column-breaking bug (1.35 KB, text/html)
2011-06-25 12:57 PDT, Julian Tibble
no flags Details

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Description Julian Tibble 2011-06-25 12:57:30 PDT
Created attachment 98598 [details]
HTML file showing column-breaking bug

See the attached test-case (column-break.html).

In Safari 5.0.5 and Chrome 12.0.742.100, the lines of text in the adjacent columns are not perfectly aligned with each other (the text in the second column is slightly higher). I believe that the lines in adjacent columns should be perfectly level (apart from the H2 heading in the second column).

Although the spec is not particularly explicit about breaking columns, the CSS3-multicol spec says that the problem of breaking columns is similar to breaking pages. The CSS2 spec for page-breaking says in section 13.3.3 that page-breaking is allowed _between_ line boxes inside a block container.

In the attached test-case I think that the column break is not occurring exactly in between line boxes, but is "borrowing" space from one line box to fill the bottom of the first column.

I believe this is a bug. Apologies if I've missed something in the spec.


Julian
Comment 1 Karthik Sarap 2011-08-09 07:02:35 PDT
As i observed that given testcase is good enough in the safari  5.0.5(7533.21.1) and where as in the chrome it seems slight mismatch in the level between the adjacent columns .

            According to the CSS3 Spec it is not so clear about the multicol elements (specifically for line spacing level) and in the css2 Spec 13.3.3 given as ,
Note: It is expected that CSS3 will specify that the relevant 'margin-top' applies (i.e., is not set to '0') after a forced page break.  

i.e., it says that it does not set the value("usedvalue" in this case) to "0" in CSS3 as it happens in Css2 spec and think this statement implies that what we are seeing in the chrome and safari browser is ok ..  

I would like to know is this relates and helps in diagnose the issue & Correct me if am wrong anywhere  ..
Comment 2 Shane Stephens 2011-10-05 20:27:22 PDT
This appears to be significantly better in Chrome 14 and WebKit head.