QmlViewer: Fix crash on exit

We can't use atexit() handler to show a warning, since whether the
QApplication object then still exists or not is undefined.

Instead, call the method directly where it makes sense (warnings about
command line arguments etc).

Task-number: QTBUG-15740
Reviewed-by: Thomas Hartmann

1 files changed, 21 insertions, 21 deletions

diff --git a/tools/qml/main.cpp b/tools/qml/main.cpp
index 209c72f..104f7b7 100644
--- a/tools/qml/main.cpp
+++ b/tools/qml/main.cpp
@@ -86,14 +86,16 @@ void myMessageOutput(QtMsgType type, const char *msg)
 QWeakPointer<LoggerWidget> logger;
 
 QString warnings;
-void showWarnings()
+void exitApp(int i)
 {
+#ifdef Q_OS_WIN
+    // Debugging output is not visible by default on Windows -
+    // therefore show modal dialog with errors instead.
     if (!warnings.isEmpty()) {
-        int argc = 0; char **argv = 0;
-        QApplication application(argc, argv); // QApplication() in main has been destroyed already.
-        Q_UNUSED(application)
         QMessageBox::warning(0, QApplication::tr("Qt QML Viewer"), warnings);
     }
+#endif
+    exit(i);
 }
 
 static QAtomicInt recursiveLock(0);
@@ -102,14 +104,16 @@ void myMessageOutput(QtMsgType type, const char *msg)
 {
     QString strMsg = QString::fromLatin1(msg);
 
-    if (!logger.isNull() && !QCoreApplication::closingDown()) {
-        if (recursiveLock.testAndSetOrdered(0, 1)) {
-            QMetaObject::invokeMethod(logger.data(), "append", Q_ARG(QString, strMsg));
-            recursiveLock = 0;
+    if (!QCoreApplication::closingDown()) {
+        if (!logger.isNull()) {
+            if (recursiveLock.testAndSetOrdered(0, 1)) {
+                QMetaObject::invokeMethod(logger.data(), "append", Q_ARG(QString, strMsg));
+                recursiveLock = 0;
+            }
+        } else {
+            warnings += strMsg;
+            warnings += QLatin1Char('\n');
         }
-    } else {
-        warnings += strMsg;
-        warnings += QLatin1Char('\n');
     }
     if (systemMsgOutput) { // Windows
         systemMsgOutput(type, msg);
@@ -165,7 +169,8 @@ void usage()
 
     qWarning(" ");
     qWarning(" Press F1 for interactive help");
-    exit(1);
+
+    exitApp(1);
 }
 
 void scriptOptsUsage()
@@ -184,7 +189,8 @@ void scriptOptsUsage()
     qWarning("  saveonexit ............................... save recording on viewer exit");
     qWarning(" ");
     qWarning(" One of record, play or both must be specified.");
-    exit(1);
+
+    exitApp(1);
 }
 
 enum WarningsConfig { ShowWarnings, HideWarnings, DefaultWarnings };
@@ -370,7 +376,7 @@ static void parseCommandLineOptions(const QStringList &arguments)
             qApp->setStartDragDistance(arguments.at(++i).toInt());
         } else if (arg == QLatin1String("-v") || arg == QLatin1String("-version")) {
             qWarning("Qt QML Viewer version %s", QT_VERSION_STR);
-            exit(0);
+            exitApp(0);
         } else if (arg == "-translation") {
             if (lastArg) usage();
             opts.translationFile = arguments.at(++i);
@@ -400,7 +406,7 @@ static void parseCommandLineOptions(const QStringList &arguments)
                 QDeclarativeEngine tmpEngine;
                 QString paths = tmpEngine.importPathList().join(QLatin1String(":"));
                 qWarning("Current search path: %s", paths.toLocal8Bit().constData());
-                exit(0);
+                exitApp(0);
             }
             opts.imports << arguments.at(++i);
         } else if (arg == "-P") {
@@ -529,12 +535,6 @@ int main(int argc, char ** argv)
     systemMsgOutput = qInstallMsgHandler(myMessageOutput);
 #endif
 
-#if defined (Q_OS_WIN)
-    // Debugging output is not visible by default on Windows -
-    // therefore show modal dialog with errors instead.
-    atexit(showWarnings);
-#endif
-
 #if defined (Q_WS_X11) || defined (Q_WS_MAC)
     //### default to using raster graphics backend for now
     bool gsSpecified = false;