diff options
author | Joerg Bornemann <joerg.bornemann@theqtcompany.com> | 2016-02-24 12:36:36 +0100 |
---|---|---|
committer | Joerg Bornemann <joerg.bornemann@theqtcompany.com> | 2016-02-29 17:52:58 +0000 |
commit | 6f75c189e1e5651b716afb316c801d080001c155 (patch) | |
tree | 02c815fc2e40c6d3eb23ebefbb04d4713f7e88c7 | |
parent | c7e213334bb70fb023e2bdc3a590dfd4605b73ba (diff) |
Fix crash in QProcess::waitForFinished on Windows
Suppose the user connects QProcess::readyReadStandardOutput with a
slot that calls QCoreApplication::processEvents.
Assume the event loop did not handle events between QProcess::start
and QProcess::waitForFinished. The process writes to stdout and exits.
QProcessPrivate::waitForFinished calls drainOutputPipes which calls
QWindowsPipeWriter::waitForReadyRead. This in turn will trigger
_q_processDied via the readyRead signal and processEvents.
_q_processDied will delete the pid object and set pid to null.
After drainOutputPipes returns, _q_processDied is called again but it
must not be called if pid is already destroyed.
Prevent calling _q_processDied if pid is null.
Task-number: QTBUG-48697
Change-Id: Iee047938ee1529057a1a43d71f4e882750903c7e
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
-rw-r--r-- | src/corelib/io/qprocess_win.cpp | 6 | ||||
-rw-r--r-- | tests/auto/corelib/io/qprocess/tst_qprocess.cpp | 33 |
2 files changed, 37 insertions, 2 deletions
diff --git a/src/corelib/io/qprocess_win.cpp b/src/corelib/io/qprocess_win.cpp index 80e6d5bb61..98ada82446 100644 --- a/src/corelib/io/qprocess_win.cpp +++ b/src/corelib/io/qprocess_win.cpp @@ -647,7 +647,8 @@ bool QProcessPrivate::waitForReadyRead(int msecs) return false; if (WaitForSingleObjectEx(pid->hProcess, 0, false) == WAIT_OBJECT_0) { bool readyReadEmitted = drainOutputPipes(); - _q_processDied(); + if (pid) + _q_processDied(); return readyReadEmitted; } @@ -752,7 +753,8 @@ bool QProcessPrivate::waitForFinished(int msecs) if (WaitForSingleObject(pid->hProcess, timer.nextSleepTime()) == WAIT_OBJECT_0) { drainOutputPipes(); - _q_processDied(); + if (pid) + _q_processDied(); return true; } diff --git a/tests/auto/corelib/io/qprocess/tst_qprocess.cpp b/tests/auto/corelib/io/qprocess/tst_qprocess.cpp index 8b8c731987..46bf1a19e8 100644 --- a/tests/auto/corelib/io/qprocess/tst_qprocess.cpp +++ b/tests/auto/corelib/io/qprocess/tst_qprocess.cpp @@ -145,6 +145,8 @@ private slots: void startStopStartStop(); void startStopStartStopBuffers_data(); void startStopStartStopBuffers(); + void processEventsInAReadyReadSlot_data(); + void processEventsInAReadyReadSlot(); // keep these at the end, since they use lots of processes and sometimes // caused obscure failures to occur in tests that followed them (esp. on the Mac) @@ -157,6 +159,7 @@ private slots: protected slots: void readFromProcess(); void exitLoopSlot(); + void processApplicationEvents(); #ifndef Q_OS_WINCE void restartProcess(); void waitForReadyReadInAReadyReadSlotSlot(); @@ -475,6 +478,11 @@ void tst_QProcess::exitLoopSlot() QTestEventLoop::instance().exitLoop(); } +void tst_QProcess::processApplicationEvents() +{ + QCoreApplication::processEvents(); +} + #ifndef Q_OS_WINCE // Reading and writing to a process is not supported on Qt/CE void tst_QProcess::echoTest2() @@ -2499,6 +2507,31 @@ void tst_QProcess::startStopStartStopBuffers() } } +void tst_QProcess::processEventsInAReadyReadSlot_data() +{ + QTest::addColumn<bool>("callWaitForReadyRead"); + + QTest::newRow("no waitForReadyRead") << false; + QTest::newRow("waitForReadyRead") << true; +} + +void tst_QProcess::processEventsInAReadyReadSlot() +{ + // Test whether processing events in a readyReadXXX slot crashes. (QTBUG-48697) + QFETCH(bool, callWaitForReadyRead); + QProcess process; + QObject::connect(&process, &QProcess::readyReadStandardOutput, + this, &tst_QProcess::processApplicationEvents); + process.start("testProcessEcho/testProcessEcho"); + QVERIFY(process.waitForStarted()); + const QByteArray data(156, 'x'); + process.write(data.constData(), data.size() + 1); + if (callWaitForReadyRead) + QVERIFY(process.waitForReadyRead()); + if (process.state() == QProcess::Running) + QVERIFY(process.waitForFinished()); +} + #endif //QT_NO_PROCESS QTEST_MAIN(tst_QProcess) |