Ignore mLegendFrame as previous sibling since it does not live in the content area frame. b=345249 r+sr=bzbarsky a=dveditz

git-svn-id: svn://10.0.0.236/branches/MOZILLA_1_8_0_BRANCH@207734 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/layout/forms/nsFieldSetFrame.cpp

@@ -628,6 +628,9 @@ nsFieldSetFrame::InsertFrames(nsIAtom*       aListName,
   aFrameList = MaybeSetLegend(aFrameList, aListName);
   if (aFrameList) {
     ReParentFrameList(aFrameList);
+    if (NS_UNLIKELY(aPrevFrame == mLegendFrame)) {
+      aPrevFrame = nsnull;
+    }
     return mContentFrame->InsertFrames(aListName, aPrevFrame, aFrameList);
   }
   return NS_OK;