Bug 296528 - Dragging file from Windows Explorer FTP into Firefox deletes the file. r=emaijala

widget/src/windows/nsClipboard.cpp

@@ -50,6 +50,7 @@
 #include "nsDataObj.h"
 #include "nsIClipboardOwner.h"
 #include "nsString.h"
+#include "nsNativeCharsetUtils.h"
 #include "nsIFormatConverter.h"
 #include "nsITransferable.h"
 #include "nsCOMPtr.h"
@@ -65,6 +66,7 @@
 #include "nsWidgetsCID.h"
 #include "nsCRT.h"
 #include "nsNetUtil.h"
+#include "nsEscape.h"
 
 #include "nsIImage.h"
 
@@ -819,6 +821,29 @@ nsClipboard :: FindURLFromNativeURL ( IDataObject* inDataObject, UINT inIndex, v
     nsMemory::Free(tempOutData);
     dataFound = PR_TRUE;
   }
+  else {
+    loadResult = GetNativeDataOffClipboard(inDataObject, inIndex, ::RegisterClipboardFormat(CFSTR_INETURLA), &tempOutData, &tempDataLen);
+    if ( NS_SUCCEEDED(loadResult) && tempOutData ) {
+      // CFSTR_INETURLA is (currently) equal to CFSTR_SHELLURL which is equal to CF_TEXT
+      // which is by definition ANSI encoded.
+      nsCString urlUnescapedA;
+      PRBool unescaped = NS_UnescapeURL(static_cast<char*>(tempOutData), tempDataLen, esc_OnlyNonASCII | esc_SkipControl, urlUnescapedA);
+
+      nsString urlString;
+      if (unescaped)
+        NS_CopyNativeToUnicode(urlUnescapedA, urlString);
+      else
+        NS_CopyNativeToUnicode(nsDependentCString(static_cast<char*>(tempOutData), tempDataLen), urlString);
+
+      // the internal mozilla URL format, text/x-moz-url, contains
+      // URL\ntitle.  Since we don't actually have a title here,
+      // just repeat the URL to fake it.
+      *outData = ToNewUnicode(urlString + NS_LITERAL_STRING("\n") + urlString);
+      *outDataLen = nsCRT::strlen(static_cast<PRUnichar*>(*outData)) * sizeof(PRUnichar);
+      nsMemory::Free(tempOutData);
+      dataFound = PR_TRUE;
+    }
+  }
 
   return dataFound;
 } // FindURLFromNativeURL

widget/src/windows/nsNativeDragTarget.cpp

@@ -46,6 +46,7 @@
 
 #include "nsIWidget.h"
 #include "nsWindow.h"
+#include "nsClipboard.h"
 
 #if (_MSC_VER == 1100)
 #define INITGUID
@@ -158,9 +159,11 @@ nsNativeDragTarget::GetGeckoDragAction(LPDATAOBJECT pData, DWORD grfKeyState,
 
   // Default is move if we can, in fact drop here,
   // and if the drop source supports a move operation.
-  if (mCanMove) {
+  // If move is not preferred (mMovePreferred is false)
-    *pdwEffect    = DROPEFFECT_MOVE;
+  // move only when the shift key is down.
+  if (mCanMove && (mMovePreferred || (grfKeyState & MK_SHIFT))) {
     *aGeckoAction = nsIDragService::DRAGDROP_ACTION_MOVE;
+    *pdwEffect    = DROPEFFECT_MOVE;
   } else {
     *aGeckoAction = nsIDragService::DRAGDROP_ACTION_COPY;
     *pdwEffect    = DROPEFFECT_COPY;
@@ -286,6 +289,20 @@ nsNativeDragTarget::DragEnter(LPDATAOBJECT pIDataSource,
   // Remember if this operation allows a move.
   mCanMove = (*pdwEffect) & DROPEFFECT_MOVE;
 
+  void* tempOutData = nsnull;
+  PRUint32 tempDataLen = 0;
+  nsresult loadResult = nsClipboard::GetNativeDataOffClipboard(
+      pIDataSource, 0, ::RegisterClipboardFormat(CFSTR_PREFERREDDROPEFFECT), &tempOutData, &tempDataLen);
+  if (NS_SUCCEEDED(loadResult) && tempOutData) {
+    NS_ASSERTION(tempDataLen == 2, "Expected word size");
+    WORD preferredEffect = *((WORD*)tempOutData);
+
+    // Mask effect coming from function call with effect preferred by the source.
+    mMovePreferred = (preferredEffect & DROPEFFECT_MOVE) != 0;
+  }
+  else
+    mMovePreferred = mCanMove;
+
   // Set the native data object into drag service
   //
   // This cast is ok because in the constructor we created a

widget/src/windows/nsNativeDragTarget.h

@@ -113,6 +113,7 @@ protected:
   ULONG            m_cRef;      // reference count
   HWND             mHWnd;
   PRBool           mCanMove;
+  PRBool           mMovePreferred;
 
   // Gecko Stuff
   nsIWidget      * mWindow;