Bug 36525

Summary:

MathML Fraction and Subsup incorrect layout

Product:

WebKit

Reporter:

Stephen Loo <shikil>

Component:

Layout and Rendering

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

alex, commit-queue, darin, fred.wang, sausset

Priority:

Version:

528+ (Nightly build)

Hardware:

OS:

OS X 10.6

Bug Depends on:

Bug Blocks:

3251

Attachments:

Description	Flags
An example of MathML of <mfrac> and <msubsup>	none
Correct layout of the xhtml.	none
Test showing the bug when msubsup is embedded in an mrow element.	none
Patch fixing the bug	none
Updated patch	none

Stephen Loo

Reported 2010-03-24 05:36:42 PDT

Created attachment 51489 [details] An example of MathML of <mfrac> and <msubsup> In my attachment example, I combine <mfrac> and <msubsup> to use, but the layout is incorrect. Please see attached xhtml for references. And the correct layout should be same as attached png.

Attachments
An example of MathML of <mfrac> and <msubsup> (588 bytes, application/xhtml+xml) 2010-03-24 05:36 PDT, Stephen Loo	no flags	Details
Correct layout of the xhtml. (8.87 KB, image/png) 2010-03-24 05:37 PDT, Stephen Loo	no flags	Details
Test showing the bug when msubsup is embedded in an mrow element. (297 bytes, application/xhtml+xml) 2010-04-03 11:10 PDT, François Sausset	no flags	Details
Patch fixing the bug (54.48 KB, patch) 2010-06-29 14:47 PDT, François Sausset	no flags	Details Formatted Diff Diff
Updated patch (54.53 KB, patch) 2010-06-29 15:12 PDT, François Sausset	no flags	Details Formatted Diff Diff
Show Obsolete (1) View All Add attachment proposed patch, testcase, etc.

Stephen Loo

Comment 1 2010-03-24 05:37:58 PDT

Created attachment 51490 [details] Correct layout of the xhtml.

François Sausset

Comment 2 2010-04-03 11:07:32 PDT

The problem does not come from the mfrac element, but from the mrow in which the msubsup is embedded. See the attachment.

François Sausset

Comment 3 2010-04-03 11:10:28 PDT

Created attachment 52497 [details] Test showing the bug when msubsup is embedded in an mrow element.

Alex Milowski

Comment 4 2010-06-22 13:47:55 PDT

Actually, math and mrow are almost the exact same rendering object (RenderMathMLRow). The cause of this is a row containing another row and stretching. The row operator stretching algorithm is doing something strange to the layout of msubsup in this context. The new layout patch in https://bugs.webkit.org/show_bug.cgi?id=40986 doesn't fix this yet.

François Sausset

Comment 5 2010-06-29 14:47:04 PDT

Created attachment 60058 [details] Patch fixing the bug

Darin Adler

Comment 6 2010-06-29 14:50:58 PDT

Comment on attachment 60058 [details] Patch fixing the bug > + if (base->firstChild()->isRenderMathMLBlock()) { What guarantees that base->firstChild() is non-null? Otherwise, this patch looks good to me.

François Sausset

Comment 7 2010-06-29 15:12:08 PDT

Created attachment 60064 [details] Updated patch I added a test to be sure that base->firstChild() exists. However, lines 100 and 101 of RenderMathMLSubSup.cpp should guarantee it.

Darin Adler

Comment 8 2010-06-29 15:28:41 PDT

(In reply to comment #7) > I added a test to be sure that base->firstChild() exists. > > However, lines 100 and 101 of RenderMathMLSubSup.cpp should guarantee it. We don't need both a test and a guarantee! Only one or the other.

François Sausset

Comment 9 2010-06-29 15:36:35 PDT

Comment on attachment 60064 [details] Updated patch Revert to previous patch to avoid unnecessary test.

WebKit Commit Bot

Comment 10 2010-06-29 15:57:59 PDT

Comment on attachment 60058 [details] Patch fixing the bug Clearing flags on attachment: 60058 Committed r62152: <http://trac.webkit.org/changeset/62152>

WebKit Commit Bot

Comment 11 2010-06-29 15:58:04 PDT

All reviewed patches have been landed. Closing bug.

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