DiffEditor: Fix test
DiffEditor: Fix test

* Add trailing newline
* Fix offset by 1 for line numbers
* Swap expected and actual result
* Join short lines

Change-Id: Ia1c618e5fc86dc16956176241205a2108a1ba3e4
Reviewed-by: Jarek Kobus <021d51876099fe64879cc5072886d1d0ff71e1ac@digia.com>

amyvmiwei/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,xianian/qt-creator,AltarBeastiful/qt-creator,farseerri/git_code,amyvmiwei/qt-creator,Distrotech/qtcreator,farseerri/git_code,AltarBeastiful/qt-creator,kuba1/qtcreator,Distrotech/qtcreator,kuba1/qtcreator,amyvmiwei/qt-creator,martyone/sailfish-qtcreator,Distrotech/qtcreator,xianian/qt-creator,maui-packages/qt-creator,xianian/qt-creator,Distrotech/qtcreator,xianian/qt-creator,kuba1/qtcreator,maui-packages/qt-creator,maui-packages/qt-creator,farseerri/git_code,kuba1/qtcreator,danimo/qt-creator,amyvmiwei/qt-creator,maui-packages/qt-creator,farseerri/git_code,martyone/sailfish-qtcreator,amyvmiwei/qt-creator,AltarBeastiful/qt-creator,farseerri/git_code,kuba1/qtcreator,kuba1/qtcreator,Distrotech/qtcreator,xianian/qt-creator,AltarBeastiful/qt-creator,amyvmiwei/qt-creator,xianian/qt-creator,maui-packages/qt-creator,maui-packages/qt-creator,martyone/sailfish-qtcreator,AltarBeastiful/qt-creator,xianian/qt-creator,Distrotech/qtcreator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,Distrotech/qtcreator,amyvmiwei/qt-creator,kuba1/qtcreator,AltarBeastiful/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,danimo/qt-creator,martyone/sailfish-qtcreator,amyvmiwei/qt-creator,kuba1/qtcreator,danimo/qt-creator,danimo/qt-creator,maui-packages/qt-creator,danimo/qt-creator,danimo/qt-creator,danimo/qt-creator,kuba1/qtcreator,danimo/qt-creator,AltarBeastiful/qt-creator,martyone/sailfish-qtcreator,AltarBeastiful/qt-creator,farseerri/git_code,danimo/qt-creator,farseerri/git_code,farseerri/git_code