getAttributeShadowInfo expects sa in dataAttribs with a

 * Several places in the LinkHandler, addNormalizedAttribute is invoked
   w/o an original value. This causes a crash in getAttributeShadow.

 * Fixes a crash on _rt/frwiki/Dialogue_du_chapon_et_de_la_poularde

 * The error on that page looks to be from the dom breaking up nested
   <a>s.

Change-Id: I5f8c757ef85463fda602178808899df9507894f3