Don't overwrite applicationName if already set.

My commit 6c973dee2cb1686ea32657 broke the case where setApplicationName
is called before the QCoreApplication constructor.
Fixed and added autotest.

Task-number: QTBUG-45283
Change-Id: If7bdb0d82be50b50a95a04027f5f9d7143c1a7ac
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

2 files changed, 22 insertions, 4 deletions

diff --git a/src/corelib/kernel/qcoreapplication.cpp b/src/corelib/kernel/qcoreapplication.cpp
index fffecbfb55..b6f839d554 100644
--- a/src/corelib/kernel/qcoreapplication.cpp
+++ b/src/corelib/kernel/qcoreapplication.cpp
@@ -326,6 +326,7 @@ struct QCoreApplicationData {
 #ifndef QT_NO_LIBRARY
         app_libpaths = 0;
 #endif
+        applicationNameSet = false;
     }
     ~QCoreApplicationData() {
 #ifndef QT_NO_LIBRARY
@@ -370,8 +371,8 @@ struct QCoreApplicationData {
 
     QString orgName, orgDomain;
     QString application; // application name, initially from argv[0], can then be modified.
-    QString applicationNameCompat; // for QDesktopServices. Only set explicitly.
     QString applicationVersion;
+    bool applicationNameSet; // true if setApplicationName was called
 
 #ifndef QT_NO_LIBRARY
     QStringList *app_libpaths;
@@ -753,7 +754,8 @@ void QCoreApplication::init()
     QCoreApplication::self = this;
 
     // Store app name (so it's still available after QCoreApplication is destroyed)
-    coreappdata()->application = d_func()->appName();
+    if (!coreappdata()->applicationNameSet)
+        coreappdata()->application = d_func()->appName();
 
     QLoggingRegistry::instance()->init();
 
@@ -2350,13 +2352,13 @@ QString QCoreApplication::organizationDomain()
 */
 void QCoreApplication::setApplicationName(const QString &application)
 {
+    coreappdata()->applicationNameSet = !application.isEmpty();
     QString newAppName = application;
     if (newAppName.isEmpty() && QCoreApplication::self)
         newAppName = QCoreApplication::self->d_func()->appName();
     if (coreappdata()->application == newAppName)
         return;
     coreappdata()->application = newAppName;
-    coreappdata()->applicationNameCompat = newAppName;
 #ifndef QT_NO_QOBJECT
     if (QCoreApplication::self)
         emit QCoreApplication::self->applicationNameChanged();
@@ -2374,7 +2376,7 @@ QString QCoreApplication::applicationName()
 // Exported for QDesktopServices (Qt4 behavior compatibility)
 Q_CORE_EXPORT QString qt_applicationName_noFallback()
 {
-    return coreappdata()->applicationNameCompat;
+    return coreappdata()->applicationNameSet ? coreappdata()->application : QString();
 }
 
 /*!
diff --git a/tests/auto/corelib/kernel/qcoreapplication/tst_qcoreapplication.cpp b/tests/auto/corelib/kernel/qcoreapplication/tst_qcoreapplication.cpp
index ff4963a960..924db17c04 100644
--- a/tests/auto/corelib/kernel/qcoreapplication/tst_qcoreapplication.cpp
+++ b/tests/auto/corelib/kernel/qcoreapplication/tst_qcoreapplication.cpp
@@ -112,6 +112,22 @@ void tst_QCoreApplication::qAppName()
     // The application name should still be available after destruction;
     // global statics often rely on this.
     QCOMPARE(QCoreApplication::applicationName(), QString::fromLatin1(appName));
+
+    // Setting the appname before creating the application should work (QTBUG-45283)
+    const QString wantedAppName("my app name");
+    {
+        int argc = 1;
+        char *argv[] = { const_cast<char*>(appName) };
+        QCoreApplication::setApplicationName(wantedAppName);
+        TestApplication app(argc, argv);
+        QCOMPARE(::qAppName(), QString::fromLatin1(appName));
+        QCOMPARE(QCoreApplication::applicationName(), wantedAppName);
+    }
+    QCOMPARE(QCoreApplication::applicationName(), wantedAppName);
+
+    // Restore to initial value
+    QCoreApplication::setApplicationName(QString());
+    QCOMPARE(QCoreApplication::applicationName(), QString());
 }
 
 void tst_QCoreApplication::argc()