ProjectExplorer: Validate pointer *before* accessing it
ProjectExplorer: Validate pointer *before* accessing it

Change-Id: I8a202aaa6961d2cc2691b13be2b76f4b7511dc0b
Reviewed-by: Tobias Hunger <012f8d714267bccc9d4766fbeace9f175fcc70c4@digia.com>

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