Replaced lots of unnecessary code with OleFlushClipboard() so that we correctly flush

the clipboard when the app quits, but only if the data on the clipboard is ours to
begin with. r=scc, bug#49354.

widget/src/windows/nsClipboard.cpp

@@ -63,7 +63,6 @@ static NS_DEFINE_IID(kCImageCID, NS_IMAGE_CID);
 nsClipboard::nsClipboard() : nsBaseClipboard()
 {
   //NS_INIT_REFCNT();
-  mDataObj        = nsnull;
   mIgnoreEmptyNotification = PR_FALSE;
   mWindow         = nsnull;
 
@@ -74,8 +73,6 @@ nsClipboard::nsClipboard() : nsBaseClipboard()
 //-------------------------------------------------------------------------
 nsClipboard::~nsClipboard()
 {
-  if ( mDataObj )
-    mDataObj->Release();
 
 }
 
@@ -213,17 +210,10 @@ NS_IMETHODIMP nsClipboard::SetNativeClipboardData ( PRInt32 aWhichClipboard )
   // Clear the native clipboard
   ::OleSetClipboard(NULL);
 
-  // Release the existing DataObject
-  if (mDataObj) {
-    mDataObj->Release();
-  }
-
   IDataObject * dataObj;
-  if (NS_OK == CreateNativeDataObject(mTransferable, &dataObj)) { // this add refs
-    // cast our native DataObject to its IDataObject pointer
-    // and put it on the clipboard
-    mDataObj = (IDataObject *)dataObj;
-    ::OleSetClipboard(mDataObj);
+  if ( NS_SUCCEEDED(CreateNativeDataObject(mTransferable, &dataObj)) ) { // this add refs
+    ::OleSetClipboard(dataObj);
+    dataObj->Release();
   }
 
   mIgnoreEmptyNotification = PR_FALSE;
@@ -883,54 +873,7 @@ static void PlaceDataOnClipboard(PRUint32 aFormat, char * aData, int aLength)
 //-------------------------------------------------------------------------
 NS_IMETHODIMP nsClipboard::ForceDataToClipboard ( PRInt32 aWhichClipboard )
 {
-  // make sure we have a good transferable
-  if ( !mTransferable || aWhichClipboard != kGlobalClipboard ) {
-    return NS_ERROR_FAILURE;
-  }
-
-  HWND nativeWin = nsnull;//(HWND)mWindow->GetNativeData(NS_NATIVE_WINDOW);
-  ::OpenClipboard(nativeWin);
-  ::EmptyClipboard();
-
-  // get flavor list that includes all flavors that can be written (including ones 
-  // obtained through conversion)
-  nsCOMPtr<nsISupportsArray> flavorList;
-  nsresult errCode = mTransferable->FlavorsTransferableCanExport ( getter_AddRefs(flavorList) );
-  if ( NS_FAILED(errCode) )
-    return NS_ERROR_FAILURE;
-
-  // Walk through flavors and see which flavor is on the native clipboard,
-  PRUint32 i;
-  PRUint32 cnt;
-  flavorList->Count(&cnt);
-  for (i=0;i<cnt;i++) {
-    nsCOMPtr<nsISupports> genericFlavor;
-    flavorList->GetElementAt ( i, getter_AddRefs(genericFlavor) );
-    nsCOMPtr<nsISupportsString> currentFlavor ( do_QueryInterface(genericFlavor) );
-    if ( currentFlavor ) {
-      nsXPIDLCString flavorStr;
-      currentFlavor->ToString(getter_Copies(flavorStr));
-      UINT format = GetFormat(flavorStr);
-
-      void   * data;
-      PRUint32 dataLen = 0;
-
-      // Get the data as a bunch-o-bytes from the clipboard
-      // this call hands back new memory with the contents copied into it
-      nsCOMPtr<nsISupports> genericDataWrapper;
-      mTransferable->GetTransferData(flavorStr, getter_AddRefs(genericDataWrapper), &dataLen);
-      nsPrimitiveHelpers::CreateDataFromPrimitive ( flavorStr, genericDataWrapper, &data, dataLen );
-
-      // now place it on the Clipboard
-      if (nsnull != data) {
-        PlaceDataOnClipboard(format, (char *)data, dataLen);
-      }
-
-      // Now, delete the memory that was created by the transferable
-      nsCRT::free ( (char *) data );
-    }
-  }
-
+  ::OleFlushClipboard();
   ::CloseClipboard();
 
   return NS_OK;

widget/src/windows/nsClipboard.h

@@ -70,7 +70,6 @@ protected:
   static void ResolveShortcut ( const char* inFileName, char** outURL ) ;
 
   nsIWidget         * mWindow;
-  IDataObject       * mDataObj;
 
 };