Fix some problems reported by clang static analyzer

Source/core/editing/markup.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009, 2010, 2011 Google Inc. All rights reserved.
  * Copyright (C) 2011 Igalia S.L.
  * Copyright (C) 2011 Motorola Mobility. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
@@ skipping 593 matching lines @@
                     accumulator.wrapWithStyleNode(fullySelectedRootStyle->style(), &document, true);
                 }
             } else {
                 // Since this node and all the other ancestors are not in the selection we want to set RangeFullySelectsNode to DoesNotFullySelectNode
                 // so that styles that affect the exterior of the node are not included.
                 accumulator.wrapWithNode(ancestor, convertBlocksToInlines, StyledMarkupAccumulator::DoesNotFullySelectNode);
             }
             if (nodes)
                 nodes->append(ancestor);
 
-            lastClosed = ancestor;
-
             if (ancestor == specialCommonAncestor)
                 break;
         }
     }
 
     // FIXME: The interchange newline should be placed in the block that it's in, not after all of the content, unconditionally.
     if (shouldAnnotate == AnnotateForInterchange && needInterchangeNewlineAfter(visibleEnd.previous()))
         accumulator.appendString(interchangeNewlineString);
 
     return accumulator.takeResults();
@@ skipping 454 matching lines @@
         return;
 
     RefPtr<Text> textNode = toText(node.get());
     RefPtr<Text> textNext = toText(next);
     textNode->appendData(textNext->data());
     if (textNext->parentNode()) // Might have been removed by mutation event.
         textNext->remove(exceptionState);
 }
 
 }