(followup of QTBUG-64239) emoji images are painted at the wrong place

colored textThis is a followup for QTBUG-64239, and the reported behavior has been reproduced by in both setup:

• backporting this commit http://code.qt.io/cgit/qt/qtbase.git/commit/?h=5.9&id=7df4dcff2cafcd9b57eb7a4812be871d956f0ec8 as a patch to my local 5.9.2 version (thanks to gentoo making that so easy)
• compiling directly qt from the git branch, specifically at this commit http://code.qt.io/cgit/qt/qtbase.git/commit/?h=5.9&id=28937559b1e03f959cd012c6b42ca988311893f5

Now, in setups combining QLabels with emojis inside several layouts, it appears the emoji bitmaps are painted at the wrong place. This can be reproduced with the attached code (which require the same font as the example from QTBUG-64239).

Here is also attached a screenshot of how it is wrongly rendered on my computer. The wrong placement is independent of whether HiDPI scaling is activated or not.