winrt: Fix potential crash in QCoreApplication

GetModuleFileName exists for Windows 10 and upwards, hence use the
generic version from the win32 mkspec. This allows to create a
QCoreApplication object with nullptr argv, as the application filename
is identified via the binary itself and not via arguments. A couple of
auto-tests use this method to create multiple application objects during
runtime.

Unfortunately we cannot apply this for msvc2013, even though MSDN states
the GetModuleFileName exists, it fails to compile for Windows Phone 8.1.

Change-Id: I2b8b988107487ef3785462f8ca40b0a6e0623e32
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

1 files changed, 33 insertions, 26 deletions

diff --git a/src/corelib/kernel/qcoreapplication_win.cpp b/src/corelib/kernel/qcoreapplication_win.cpp
index 324b664a1a..1af1d44f2e 100644
--- a/src/corelib/kernel/qcoreapplication_win.cpp
+++ b/src/corelib/kernel/qcoreapplication_win.cpp
@@ -49,7 +49,10 @@ QT_BEGIN_NAMESPACE
 
 int appCmdShow = 0;
 
-#if defined(Q_OS_WINRT)
+// GetModuleFileName only exists for MSVC2015 and upwards for WinRT, meaning
+// Windows 10 (Mobile). Hence take the first argument passed to the
+// QCoreApplication contructor for older versions as a fallback on older platforms.
+#if defined(Q_OS_WINRT) && _MSC_VER < 1900
 
 Q_CORE_EXPORT QString qAppFileName()
 {
@@ -61,31 +64,7 @@ QString QCoreApplicationPrivate::appName() const
     return QFileInfo(QCoreApplication::arguments().first()).baseName();
 }
 
-#else
-
-Q_CORE_EXPORT HINSTANCE qWinAppInst()                // get Windows app handle
-{
-    return GetModuleHandle(0);
-}
-
-Q_CORE_EXPORT HINSTANCE qWinAppPrevInst()                // get Windows prev app handle
-{
-    return 0;
-}
-
-Q_CORE_EXPORT int qWinAppCmdShow()                        // get main window show command
-{
-#if defined(Q_OS_WINCE)
-    return appCmdShow;
-#else
-    STARTUPINFO startupInfo;
-    GetStartupInfo(&startupInfo);
-
-    return (startupInfo.dwFlags & STARTF_USESHOWWINDOW)
-        ? startupInfo.wShowWindow
-        : SW_SHOWDEFAULT;
-#endif
-}
+#else // !(defined(Q_OS_WINRT) && _MSC_VER < 1900)
 
 Q_CORE_EXPORT QString qAppFileName()                // get application file name
 {
@@ -133,6 +112,34 @@ QString QCoreApplicationPrivate::appName() const
     return QFileInfo(qAppFileName()).baseName();
 }
 
+#endif // !(defined(Q_OS_WINRT) && _MSC_VER < 1900)
+
+#ifndef Q_OS_WINRT
+
+Q_CORE_EXPORT HINSTANCE qWinAppInst()                // get Windows app handle
+{
+    return GetModuleHandle(0);
+}
+
+Q_CORE_EXPORT HINSTANCE qWinAppPrevInst()                // get Windows prev app handle
+{
+    return 0;
+}
+
+Q_CORE_EXPORT int qWinAppCmdShow()                        // get main window show command
+{
+#if defined(Q_OS_WINCE)
+    return appCmdShow;
+#else
+    STARTUPINFO startupInfo;
+    GetStartupInfo(&startupInfo);
+
+    return (startupInfo.dwFlags & STARTF_USESHOWWINDOW)
+        ? startupInfo.wShowWindow
+        : SW_SHOWDEFAULT;
+#endif
+}
+
 /*****************************************************************************
   qWinMain() - Initializes Windows. Called from WinMain() in qtmain_win.cpp
  *****************************************************************************/