use short id in ancestor

rhodecode/templates/compare/compare_cs.html

@@ -1,36 +1,36 b''
 ## Changesets table !
 <div class="container">
   %if not c.cs_ranges:
     <span class="empty_data">${_('No changesets')}</span>
   %else:
     <table class="compare_view_commits noborder">
     %for cnt, cs in enumerate(c.cs_ranges):
         <tr>
         <td><div class="gravatar"><img alt="gravatar" src="${h.gravatar_url(h.email_or_none(cs.author),14)}"/></div></td>
         <td>
           %if cs.raw_id in c.statuses:
             <div title="${c.statuses[cs.raw_id][1]}" class="changeset-status-ico"><img src="${h.url('/images/icons/flag_status_%s.png' % c.statuses[cs.raw_id][0])}" /></div>
           %endif
         </td>
         <td>${h.link_to('r%s:%s' % (cs.revision,h.short_id(cs.raw_id)),h.url('changeset_home',repo_name=c.other_repo.repo_name,revision=cs.raw_id))}
         %if c.as_form:
           ${h.hidden('revisions',cs.raw_id)}
         %endif
         </td>
         <td><div class="author">${h.person(cs.author)}</div></td>
         <td><span class="tooltip" title="${h.tooltip(h.age(cs.date))}">${cs.date}</span></td>
         <td><div class="message tooltip" title="${h.tooltip(cs.message)}" style="white-space:normal">${h.urlify_commit(h.shorter(cs.message, 60),c.repo_name)}</div></td>
         </tr>
     %endfor
     </table>
     %if c.ancestor:
     <span class="ancestor">${_('Ancestor')}:
-      ${h.link_to(c.ancestor,h.url('changeset_home',repo_name=c.repo_name,revision=c.ancestor))}
+      ${h.link_to(h.short_id(c.ancestor),h.url('changeset_home',repo_name=c.repo_name,revision=c.ancestor))}
     </span>
     %endif
     %if c.as_form:
       ${h.hidden('ancestor_rev',c.ancestor)}
       ${h.hidden('merge_rev',c.cs_ranges[-1].raw_id)}
     %endif
   %endif
 </div>