Merge 120219 - [Chromium] WebFrameImpl::find doesn't work for searching from a selection.

Source/WebKit/chromium/src/WebFrameImpl.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1548 matching lines @@
 }
 
 bool WebFrameImpl::find(int identifier,
                         const WebString& searchText,
                         const WebFindOptions& options,
                         bool wrapWithinFrame,
                         WebRect* selectionRect)
 {
     WebFrameImpl* mainFrameImpl = viewImpl()->mainFrameImpl();
 
-    if (!options.findNext) {
+    if (!options.findNext)
         frame()->page()->unmarkAllTextMatches();
+    else
+        setMarkerActive(m_activeMatch.get(), false);
+
+    if (m_activeMatch && m_activeMatch->ownerDocument() != frame()->document())
         m_activeMatch = 0;
-    } else
-        setMarkerActive(m_activeMatch.get(), false);
 
     // If the user has selected something since the last Find operation we want
     // to start from there. Otherwise, we start searching from where the last Find
     // operation left off (either a Find or a FindNext operation).
     VisibleSelection selection(frame()->selection()->selection());
     bool activeSelection = !selection.isNone();
     if (activeSelection) {
         m_activeMatch = selection.firstRange().get();
         frame()->selection()->clear();
     }
@@ skipping 594 matching lines @@
             node = node->traverseNextNode();
         }
 
         // No node related to the active match was focusable, so set the
         // active match as the selection (so that when you end the Find session,
         // you'll have the last thing you found highlighted) and make sure that
         // we have nothing focused (otherwise you might have text selected but
         // a link focused, which is weird).
         frame()->selection()->setSelection(m_activeMatch.get());
         frame()->document()->setFocusedNode(0);
+
+        // Finally clear the active match, for two reasons:
+        // We just finished the find 'session' and we don't want future (potentially
+        // unrelated) find 'sessions' operations to start at the same place.
+        // The WebFrameImpl could get reused and the m_activeMatch could end up pointing
+        // to a document that is no longer valid. Keeping an invalid reference around
+        // is just asking for trouble.
+        m_activeMatch = 0;
     }
 }
 
 void WebFrameImpl::didFail(const ResourceError& error, bool wasProvisional)
 {
     if (!client())
         return;
     WebURLError webError = error;
     if (wasProvisional)
         client()->didFailProvisionalLoad(this, webError);
@@ skipping 153 matching lines @@
 
     String scriptResult;
     if (!result.getString(scriptResult))
         return;
 
     if (!m_frame->navigationScheduler()->locationChangePending())
         m_frame->document()->loader()->writer()->replaceDocument(scriptResult, ownerDocument.get());
 }
 
 } // namespace WebKit