testlib: Defer signal dumper start until tests are ready to run

We don't want the signal dumper to pick up signals that our own
test machinery produces, such as the ones emitted from the watchdog
thread startup and shutdown. This would otherwise produce:

 tst_Signaldumper::initTestCase() Signal: QThread(7fc969e0d870) started ()

At startup, and at shutdown even more confusingly:

 tst_Signaldumper::UnknownTestFunc() Signal: QThread(7fc969e0d870) finished ()

Change-Id: I9e81fa168eaa92551d38d5576973bbf95ac23364
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

3 files changed, 18 insertions, 3 deletions

diff --git a/src/testlib/qsignaldumper.cpp b/src/testlib/qsignaldumper.cpp
index 8510b3ed6f..f43b3a8d92 100644
--- a/src/testlib/qsignaldumper.cpp
+++ b/src/testlib/qsignaldumper.cpp
@@ -170,8 +170,16 @@ static void qSignalDumperCallbackEndSignal(QObject *caller, int /*signal_index*/
 
 }
 
+void QSignalDumper::setEnabled(bool enabled)
+{
+    s_isEnabled = enabled;
+}
+
 void QSignalDumper::startDump()
 {
+    if (!s_isEnabled)
+        return;
+
     static QSignalSpyCallbackSet set = { QTest::qSignalDumperCallback,
         QTest::qSignalDumperCallbackSlot, QTest::qSignalDumperCallbackEndSignal, nullptr };
     qt_register_signal_spy_callbacks(&set);
@@ -194,4 +202,6 @@ void QSignalDumper::clearIgnoredClasses()
         QTest::ignoreClasses()->clear();
 }
 
+bool QSignalDumper::s_isEnabled = false;
+
 QT_END_NAMESPACE
diff --git a/src/testlib/qsignaldumper_p.h b/src/testlib/qsignaldumper_p.h
index 0f443fd612..e211f5c059 100644
--- a/src/testlib/qsignaldumper_p.h
+++ b/src/testlib/qsignaldumper_p.h
@@ -60,11 +60,14 @@ class QByteArray;
 class QSignalDumper
 {
 public:
+    static void setEnabled(bool);
     static void startDump();
     static void endDump();
 
     static void ignoreClass(const QByteArray &klass);
     static void clearIgnoredClasses();
+private:
+    static bool s_isEnabled;
 };
 
 QT_END_NAMESPACE
diff --git a/src/testlib/qtestcase.cpp b/src/testlib/qtestcase.cpp
index e352f72e20..6b55ae43c6 100644
--- a/src/testlib/qtestcase.cpp
+++ b/src/testlib/qtestcase.cpp
@@ -643,7 +643,7 @@ Q_TESTLIB_EXPORT void qtest_qParseArgs(int argc, const char *const argv[], bool
         } else if (strcmp(argv[i], "-v2") == 0) {
             QTestLog::setVerboseLevel(2);
         } else if (strcmp(argv[i], "-vs") == 0) {
-            QSignalDumper::startDump();
+            QSignalDumper::setEnabled(true);
         } else if (strcmp(argv[i], "-o") == 0) {
             if (i + 1 >= argc) {
                 fprintf(stderr, "-o needs an extra parameter specifying the filename and optional format\n");
@@ -1485,6 +1485,8 @@ void TestMethods::invokeTests(QObject *testObject) const
         watchDog.reset(new WatchDog);
     }
 
+    QSignalDumper::startDump();
+
     if (!QTestResult::skipCurrentTest() && !QTest::currentTestFailed()) {
         if (m_initTestCaseMethod.isValid())
             m_initTestCaseMethod.invoke(testObject, Qt::DirectConnection);
@@ -1517,6 +1519,8 @@ void TestMethods::invokeTests(QObject *testObject) const
     }
     QTestResult::finishedCurrentTestFunction();
     QTestResult::setCurrentTestFunction(nullptr);
+
+    QSignalDumper::endDump();
 }
 
 #if defined(Q_OS_WIN)
@@ -1965,8 +1969,6 @@ void QTest::qCleanup()
     delete QBenchmarkGlobalData::current;
     QBenchmarkGlobalData::current = nullptr;
 
-    QSignalDumper::endDump();
-
 #if defined(Q_OS_MACOS)
     IOPMAssertionRelease(macPowerSavingDisabled);
 #endif