[Development] Backporting QTextLayout Performance Improvements to Qt4

[Milian Wolff]

Hey all,

I'd like to ask again whether I could backport some performance improvements 
in QTextLayout/QTextEngine from Qt5 to Qt4.

Most notably there is https://codereview.qt-project.org/#change,34112 which 
effects us in Kate/KDE as outlined here: 
https://bugs.kde.org/show_bug.cgi?id=225228

The changeset above was merged in Qt5 and matured there, see
https://codereview.qt-project.org/#change,34118

What I propose is to sync the current status of QTextLayout/QTextEngine from 
Qt5, put it into a patchset for Qt4 and get it into the next Qt4 release.

Would this be accepted? Or is there still a policy which forbids performance 
improvements to be merged into Qt4? Considering that the above makes the Kate 
editor practically useless for some files (freezes for multiple minutes), I 
personally see this as a bug fix anyways...

Bye
-- 
Milian Wolff
mail at milianw.de
http://milianw.de