From 6317aac66caea8f5119ca13af8d87b9edf5bf1d0 Mon Sep 17 00:00:00 2001
From: Karl Tomlinson <karlt+@karlt.net>
Date: Tue, 17 Apr 2012 13:00:26 +1200
Subject: [PATCH] b=497498 prevent GetTargetDragData (and IsTargetContextList)
 from being called without a target GtkWidget r=roc

--HG--
extra : rebase_source : 4c6d856abbe49913b74da4d9640d47a9870c2210
---
 widget/gtk2/nsDragService.cpp | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/widget/gtk2/nsDragService.cpp b/widget/gtk2/nsDragService.cpp
index 1840281f038..b166b824571 100644
--- a/widget/gtk2/nsDragService.cpp
+++ b/widget/gtk2/nsDragService.cpp
@@ -547,6 +547,15 @@ NS_IMETHODIMP
 nsDragService::GetNumDropItems(PRUint32 * aNumItems)
 {
     PR_LOG(sDragLm, PR_LOG_DEBUG, ("nsDragService::GetNumDropItems"));
+
+    if (!mTargetWidget) {
+        PR_LOG(sDragLm, PR_LOG_DEBUG,
+               ("*** warning: GetNumDropItems \
+               called without a valid target widget!\n"));
+        *aNumItems = 0;
+        return NS_OK;
+    }
+
     bool isList = IsTargetContextList();
     if (isList)
         mSourceDataItems->Count(aNumItems);
@@ -574,12 +583,18 @@ nsDragService::GetData(nsITransferable * aTransferable,
     if (!aTransferable)
         return NS_ERROR_INVALID_ARG;
 
+    if (!mTargetWidget) {
+        PR_LOG(sDragLm, PR_LOG_DEBUG,
+               ("*** warning: GetData \
+               called without a valid target widget!\n"));
+        return NS_ERROR_FAILURE;
+    }
+
     // get flavor list that includes all acceptable flavors (including
     // ones obtained through conversion). Flavors are nsISupportsStrings
     // so that they can be seen from JS.
-    nsresult rv = NS_ERROR_FAILURE;
     nsCOMPtr<nsISupportsArray> flavorList;
-    rv = aTransferable->FlavorsTransferableCanImport(
+    nsresult rv = aTransferable->FlavorsTransferableCanImport(
                         getter_AddRefs(flavorList));
     if (NS_FAILED(rv))
         return rv;
@@ -878,10 +893,10 @@ nsDragService::IsDataFlavorSupported(const char *aDataFlavor,
     *_retval = false;
 
     // check to make sure that we have a drag object set, here
-    if (!mTargetDragContext) {
+    if (!mTargetWidget) {
         PR_LOG(sDragLm, PR_LOG_DEBUG,
                ("*** warning: IsDataFlavorSupported \
-               called without a valid drag context!\n"));
+               called without a valid target widget!\n"));
         return NS_OK;
     }
 
@@ -1074,9 +1089,6 @@ nsDragService::IsTargetContextList(void)
 {
     bool retval = false;
 
-    if (!mTargetDragContext)
-        return retval;
-
     // gMimeListType drags only work for drags within a single process.
     // The gtk_drag_get_source_widget() function will return NULL if the
     // source of the drag is another app, so we use it to check if a