What happen is this:
When QProcessPrivate::findExitCode is called (in qprocess_win.cpp), pid is 0, hence the immediate crash.
Simply adding "if (pid)" solves the problem.
Note: my code was not revealling this problem with Qt 4.8.5
Note: I have entered the maybe related issue in the same time:
|For Gerrit Dashboard: QTBUG-33731|
|100401,4||QProcess/Windows: fix crash in findExitCode()||5.4||qt/qtbase||Status: ABANDONED||-2||0|
|105391,4||QProcess/Win: fix sporadic crash||5.4||qt/qtbase||Status: MERGED||+2||0|
|303323,2||QProcess/Win: Avoid reentering the code in _q_processDied()||dev||qt/qtbase||Status: MERGED||+2||0|