Index: mozilla/layout/generic/nsTextFrame.cpp
===================================================================
RCS file: /cvsroot/mozilla/layout/generic/nsTextFrame.cpp,v
retrieving revision 1.575
diff -pU30 -r1.575 mozilla/layout/generic/nsTextFrame.cpp
--- mozilla/layout/generic/nsTextFrame.cpp
+++ mozilla/layout/generic/nsTextFrame.cpp
@@ -4476,111 +4476,111 @@ nsTextFrame::GetChildFrameContainingOffs
     }
     else {
       if (contentOffset != mContentLength) //that condition was only for when there is a choice
         return NS_ERROR_FAILURE;
     }
   }
 
   if (inContentOffset < mContentOffset) //could happen with floats!
   {
     *outChildFrame = GetPrevInFlow();
     if (*outChildFrame)
       return (*outChildFrame)->GetChildFrameContainingOffset(inContentOffset, inHint,
         outFrameContentOffset,outChildFrame);
     else
       return NS_OK; //this can't be the right thing to do?
   }
   
   *outFrameContentOffset = contentOffset;
   *outChildFrame = this;
   return NS_OK;
 }
 
 
 NS_IMETHODIMP
 nsTextFrame::PeekOffset(nsPresContext* aPresContext, nsPeekOffsetStruct *aPos) 
 {
   DEBUG_VERIFY_NOT_DIRTY(mState);
   if (mState & NS_FRAME_IS_DIRTY)
     return NS_ERROR_UNEXPECTED;
 
+  if (!aPos || !mContent)
+    return NS_ERROR_NULL_POINTER;
+
 #ifdef IBMBIDI
   // XXX TODO: - this explanation may not be accurate
   //           - need to better explain for what happens when you move
   //             from the end of a line to the beginning of the next 
   //             despite not making a move logically within the text.
   //
   // When you move your caret by in some visual direction, and you find the
   // new position is at the edge of a line (beginning or end), you usually
   // want to stay on the current line rather than move to the next or the 
   // previous one; however, if you want to get to the edge of the next or
   // the previous word (i.e. you're 'eating white space' when moving
   // between words), and you couldn't find the word in the current line,
   // you do _not_ want to stay on the current line - you want to get to that
   // word.
   //
   // When your frames are ordered the same way logically as they are
   // visually (e.g. when they're frames of LTR text displayed in
   // left-then-down order), this translates to terms of 'prefer left' or
   // 'prefer right', i.e. if you move to the left and hit the beginning of
   // the line you have to choose between the frame "on the left" - the last
   // frame on the previous line - and the frame "on the right" - the
   // first frame of the current line.
   //
   // When the frames are displayed in right-then-down order (i.e. frames
   // within an RTL line), the last sentence remains correct, but now
   // the directions are reversed - if you're moving left, you hit the end
   // of a line; the frame closer to your original position is the one
   // "on the right" - the last frame on the current line - rather than the
   // one "on the left" - the first frame on the next
   // line.
   //
   // Note (for visual caret movement):
   // eDirPrevious means 'left-then-up' if the containing block is LTR, 
   // 'right-then-up' if it is RTL.
   // eDirNext means 'right-then-down' if the containing block is LTR, 
   // 'left-then-down' if it is RTL.
   // Between paragraphs, eDirPrevious means "go to the visual end of the 
   // previous paragraph", and eDirNext means "go to the visual beginning of 
   // the next paragraph"
 
   PRBool isReverseDirection = aPos->mVisual ?
     (NS_GET_EMBEDDING_LEVEL(this) & 1) != (NS_GET_BASE_LEVEL(this) & 1) : PR_FALSE;
   PRBool movementIsInFrameDirection = 
     ((aPos->mDirection == eDirNext) && !isReverseDirection) ||
     ((aPos->mDirection == eDirPrevious) && isReverseDirection);
 
 #endif
 
-  if (!aPos || !mContent)
-    return NS_ERROR_NULL_POINTER;
-
   // XXX TODO: explain this policy; why the assymetry between
   // too high and too low start offsets?
   //
   // There are 4 possible ranges of aPos->mStartOffset:
   //
   //            0    mContentOffset   mContentOffset+mContentLength
   //            |          |               |
   //   range #1 | range #2 |    range #3   | range #4
   //                        ***************
   //                       our frame's part
   //                        of the content
   //
   // Range   Policy
   // ------------------------------------------------------------------------
   //  #1     Assume the start position is at the end of the content of 'this'
   //  #2     Round up the position to the beginning of our frame
   //  #3     No change necessary
   //  #4     Delegate the PeekOffset() to the next frame (according
   //         to the direction, either to our left or our right)
   // 
   // Note: the diagram above is drawn left-to-right, but advancing
   // in the content may sometimes mean going right-to-left
   
   if (aPos->mStartOffset < 0 )
     aPos->mStartOffset = mContentLength + mContentOffset;
   if (aPos->mStartOffset < mContentOffset){
     aPos->mStartOffset = mContentOffset;
   }
   if (aPos->mStartOffset > (mContentOffset + mContentLength)){
     nsIFrame *nextContinuation = GetNextContinuation();