guard against nullptr

[wxWidgets.git] / src / msw / app.cpp

diff --git a/src/msw/app.cpp b/src/msw/app.cpp
index 81261ce15f0aa310a5fa93e38fea6864d252a5f1..8df236020fc881019c00bcc13610558a0910381d 100644 (file)
--- a/src/msw/app.cpp
+++ b/src/msw/app.cpp
@@ -219,6 +219,7 @@ void wxGUIAppTraits::AfterChildWaitLoop(void *dataOrig)
     delete data;
 }
 
+#if wxUSE_THREADS
 bool wxGUIAppTraits::DoMessageFromThreadWait()
 {
     // we should return false only if the app should exit, i.e. only if
@@ -233,14 +234,20 @@ bool wxGUIAppTraits::DoMessageFromThreadWait()
     return evtLoop->Dispatch();
 }
 
-DWORD wxGUIAppTraits::WaitForThread(WXHANDLE hThread)
+DWORD wxGUIAppTraits::WaitForThread(WXHANDLE hThread, int flags)
 {
-    // if we don't have a running event loop, we shouldn't wait for the
-    // messages as we never remove them from the message queue and so we enter
-    // an infinite loop as MsgWaitForMultipleObjects() keeps returning
-    // WAIT_OBJECT_0 + 1
-    if ( !wxEventLoop::GetActive() )
+    // We only ever dispatch messages from the main thread and, additionally,
+    // even from the main thread we shouldn't wait for the message if we don't
+    // have a running event loop as we would never remove them from the message
+    // queue then and so we would enter an infinite loop as
+    // MsgWaitForMultipleObjects() keeps returning WAIT_OBJECT_0 + 1.
+    if ( flags == wxTHREAD_WAIT_BLOCK ||
+            !wxIsMainThread() ||
+                !wxEventLoop::GetActive() )
+    {
+        // Simple blocking wait.
         return DoSimpleWaitForThread(hThread);
+    }
 
     return ::MsgWaitForMultipleObjects
              (
@@ -252,6 +259,7 @@ DWORD wxGUIAppTraits::WaitForThread(WXHANDLE hThread)
                QS_ALLPOSTMESSAGE
              );
 }
+#endif // wxUSE_THREADS
 
 wxPortId wxGUIAppTraits::GetToolkitVersion(int *majVer, int *minVer) const
 {
@@ -296,6 +304,8 @@ wxEventLoopBase* wxGUIAppTraits::CreateEventLoop()
 
 #ifndef __WXWINCE__
 
+#if wxUSE_DYNLIB_CLASS
+
 #include <wx/dynlib.h>
 
 namespace
@@ -572,6 +582,20 @@ bool wxGUIAppTraits::WriteToStderr(const wxString& text)
     return s_consoleStderr.IsOkToUse() && s_consoleStderr.Write(text);
 }
 
+#else // !wxUSE_DYNLIB_CLASS
+
+bool wxGUIAppTraits::CanUseStderr()
+{
+    return false;
+}
+
+bool wxGUIAppTraits::WriteToStderr(const wxString& WXUNUSED(text))
+{
+    return false;
+}
+
+#endif // wxUSE_DYNLIB_CLASS/!wxUSE_DYNLIB_CLASS
+
 #endif // !__WXWINCE__
 
 // ===========================================================================