Fix crash in wxMediaCtrl::GetDownloadProgress() with ActiveMovie backend.

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

diff --git a/src/msw/mediactrl_am.cpp b/src/msw/mediactrl_am.cpp
index 66db8cf30a883074eeb69725a0b3f40d17461960..dd80e3963dbe98a062b176d3b8ba0221f0e040f9 100644 (file)
--- a/src/msw/mediactrl_am.cpp
+++ b/src/msw/mediactrl_am.cpp
@@ -2092,36 +2092,37 @@ void wxAMMediaBackend::DoGetDownloadProgress(wxLongLong* pLoadProgress,
                                              wxLongLong* pLoadTotal)
 {
 #ifndef __WXWINCE__
-    LONGLONG loadTotal = 0, loadProgress = 0;
-    IUnknown* pFG;
-    IAMOpenProgress* pOP;
-    HRESULT hr;
-    hr = m_pAM->get_FilterGraph(&pFG);
-    if(SUCCEEDED(hr))
+    IUnknown* pFG = NULL;
+
+    HRESULT hr = m_pAM->get_FilterGraph(&pFG);
+
+    // notice that the call above may return S_FALSE and leave pFG NULL
+    if(SUCCEEDED(hr) && pFG)
     {
+        IAMOpenProgress* pOP = NULL;
         hr = pFG->QueryInterface(IID_IAMOpenProgress, (void**)&pOP);
-        if(SUCCEEDED(hr))
-    {
+        if(SUCCEEDED(hr) && pOP)
+        {
+            LONGLONG
+                loadTotal = 0,
+                loadProgress = 0;
             hr = pOP->QueryProgress(&loadTotal, &loadProgress);
             pOP->Release();
+
+            if(SUCCEEDED(hr))
+            {
+                *pLoadProgress = loadProgress;
+                *pLoadTotal = loadTotal;
+                pFG->Release();
+                return;
+            }
         }
         pFG->Release();
     }
+#endif // !__WXWINCE__
 
-    if(SUCCEEDED(hr))
-    {
-        *pLoadProgress = loadProgress;
-        *pLoadTotal = loadTotal;
-    }
-    else
-#endif
-    {
-        // When not loading from a URL QueryProgress will return
-        // E_NOINTERFACE or whatever
-        // wxAMFAIL(hr);
-        *pLoadProgress = 0;
-        *pLoadTotal = 0;
-    }
+    *pLoadProgress = 0;
+    *pLoadTotal = 0;
 }
 
 //---------------------------------------------------------------------------