Caret skips blank line using down-arrow key in preformatted text (e.g. View Source). Bug 298690, patch by Uri Bernstein <uriber@gmail.com>, r+sr=roc

layout/generic/nsFrame.cpp

@@ -3292,18 +3292,14 @@ nsFrame::GetNextPrevLineFromeBlockFrame(nsPresContext* aPresContext,
         if (!resultFrame->HasView())
         {
           rect = resultFrame->GetRect();
-          if (!rect.width || !rect.height)
-            result = NS_ERROR_FAILURE;
-          else {
-            nsIView* view;
-            nsPoint offset;
-            resultFrame->GetOffsetFromView(offset, &view);
-            result = resultFrame->GetContentAndOffsetsFromPoint(context,point - offset,
-                                          getter_AddRefs(aPos->mResultContent),
-                                          aPos->mContentOffset,
-                                          aPos->mContentOffsetEnd,
-                                          aPos->mPreferLeft);
-          }
+          nsIView* view;
+          nsPoint offset;
+          resultFrame->GetOffsetFromView(offset, &view);
+          result = resultFrame->GetContentAndOffsetsFromPoint(context,point - offset,
+                                        getter_AddRefs(aPos->mResultContent),
+                                        aPos->mContentOffset,
+                                        aPos->mContentOffsetEnd,
+                                        aPos->mPreferLeft);
           if (NS_SUCCEEDED(result))
           {
             PRBool selectable;

layout/generic/nsLineBox.cpp

@@ -784,7 +784,7 @@ nsLineIterator::FindFrameAt(PRInt32 aLineNumber,
     return NS_OK;
   }
 
-  if (line->mBounds.width == 0)
+  if (line->mBounds.width == 0 && line->mBounds.height == 0)
     return NS_ERROR_FAILURE;
 
   nsIFrame* frame = line->mFirstChild;

layout/generic/nsTextFrame.cpp

@@ -3598,11 +3598,6 @@ nsTextFrame::GetPosition(nsPresContext*  aPresContext,
       // no need to worry about justification, that's always on the slow path
       PrepareUnicodeText(tx, &indexBuffer, &paintBuffer, &textLength);
 
-      if (textLength <=0) {
-        //invalid frame to get position on
-        return NS_ERROR_FAILURE;
-      }
-
 //IF STYLE SAYS TO SELECT TO END OF FRAME HERE...
       PRInt32 prefInt =
         nsContentUtils::GetIntPref("browser.drag_out_of_frame_style");
@@ -3624,7 +3619,11 @@ nsTextFrame::GetPosition(nsPresContext*  aPresContext,
         }
       }
 
-      if (!outofstylehandled) //then we need to track based on the X coord only
+      if (textLength <= 0) {
+        aContentOffset = mContentOffset;
+        aContentOffsetEnd = aContentOffset;
+      }
+      else if (!outofstylehandled) //then we need to track based on the X coord only
       {
 //END STYLE IF
         PRInt32* ip = indexBuffer.mBuffer;