Bug 79402

Summary:

[Qt] Font related problem with newer Qt5

Product:

WebKit

Reporter:

Csaba Osztrogonác <ossy>

Component:

Tools / Tests

Assignee:

Simon Hausmann <hausmann>

Status:

RESOLVED FIXED

Severity:

Blocker

CC:

abecsi, hausmann, kbalazs, kenneth, ossy, pierre.rossi

Priority:

Keywords:

Qt, QtTriaged

Version:

528+ (Nightly build)

Hardware:

All

OS:

All

Bug Depends on:

Bug Blocks:

79328

Attachments:

Description	Flags
png with the lateset pinned Qt5 hash	none
png with the lateset Qt5 hash	none
Patch	none

Csaba Osztrogonác

Reported 2012-02-23 14:40:07 PST

The latest pinned Qt5 hash works fine - 1baa51c3d06dfaf08afe16e3e7dd77a63052a419 I tried to do update it to 59eebee2600505b2d207d651fb5aa0da979f0f6a, but I got a strange font related problem. Almost all tests ~5500 fail, because the default font is changed for some reason. :-/ We should find the reason and fix it before updating. I don't thinks if skipping ~5500 tests is a good idea and we can't check ~5500 manually and then maintain ~5500 expected files for Qt 4.8 and Qt 5.0 parallel. :( Simon, Balázs, you are font experts. Could you check what happened?

Attachments
png with the lateset pinned Qt5 hash (11.83 KB, image/png) 2012-02-23 14:44 PST, Csaba Osztrogonác	no flags	Details
png with the lateset Qt5 hash (12.18 KB, image/png) 2012-02-23 14:44 PST, Csaba Osztrogonác	no flags	Details
Patch (1.66 KB, patch) 2012-02-24 03:32 PST, Simon Hausmann	no flags	Details Formatted Diff Diff
View All Add attachment proposed patch, testcase, etc.

Csaba Osztrogonác

Comment 1 2012-02-23 14:41:09 PST

I'll attach png results soon.

Csaba Osztrogonác

Comment 2 2012-02-23 14:44:09 PST

Created attachment 128559 [details] png with the lateset pinned Qt5 hash

Csaba Osztrogonác

Comment 3 2012-02-23 14:44:39 PST

Created attachment 128561 [details] png with the lateset Qt5 hash

Csaba Osztrogonác

Comment 4 2012-02-23 14:47:31 PST

I forgot to mention, if you would like to debug, you have to apply the buildfix from bug79328 for the newer Qt5.

Simon Hausmann

Comment 5 2012-02-24 03:22:04 PST

I spent a bit of time looking into this and this is what I think happened: There are two differences that we can observe, a difference in _metrics_ (*-expected.txt) as well as in the _visual rendering_ (attached png files). I do believe the difference in the png files is _not_ caused by any _recent_ changes (i.e. from last week's qt5 pinned hash to current one), but by some more general changes in Qt 5. I don't think we should do anything about them until we drop support for Qt 4. The difference in _metrics_ I believe is caused by an intentional behavioural change in Qt 5 http://codereview.qt-project.org/#change,15169 (or by one of its follow-up patches). I'm looking into compensation for this in WebKit to give us Qt 4 like results. In the future perhaps we can make the Qt 4 rendering behave like Qt 5 (in terms of metrics) and rebase all our results (or drop qt4 and rebase anyway).

Simon Hausmann

Comment 6 2012-02-24 03:32:19 PST

Created attachment 128701 [details] Patch

Csaba Osztrogonác

Comment 7 2012-02-24 06:39:14 PST

Comment on attachment 128701 [details] Patch Clearing flags on attachment: 128701 Committed r108788: <http://trac.webkit.org/changeset/108788>

Csaba Osztrogonác

Comment 8 2012-02-24 06:39:22 PST

All reviewed patches have been landed. Closing bug.

Balazs Kelemen

Comment 9 2012-02-24 06:49:14 PST

> I do believe the difference in the png files is _not_ caused by any _recent_ changes (i.e. from last week's qt5 pinned hash to current one), but by some more general changes in Qt 5. I don't think we should do anything about them until we drop support for Qt 4. > I believe the png files are just very out-of-date, AFAIK pixel tests do not pass even with Qt4.

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