catch TypeResolverError in case a parent entity also implements ITree but is...

catch TypeResolverError in case a parent entity also implements ITree but is not the root entity (closes #1956066)

entities.py

@@ -7,6 +7,7 @@
 __docformat__ = "restructuredtext en"
 
 from logilab.common.textutils import normalize_text
+from rql import TypeResolverException
 
 from cubicweb.view import EntityView
 from cubicweb.selectors import is_instance
@@ -78,8 +79,12 @@
         cpath = itree.path()[1:]
         indentlevel = len(cpath) - 1
         for i, ceid in enumerate(cpath):
-            comment = self._cw.execute('Any C,T,D WHERE C creation_date D, C content T, C eid %(x)s',
-                                       {'x': ceid}, build_descr=True).get_entity(0, 0)
+            try:
+                comment = self._cw.execute('Any C,T,D WHERE C creation_date D, C content T, C eid %(x)s',
+                                           {'x': ceid}, build_descr=True).get_entity(0, 0)
+            except TypeResolverException:
+                # not a comment
+                break
             strings.append(comment.view('fulltext', indentlevel=indentlevel-i,
                                         withauthor=i!=indentlevel).strip() + '\n')
         strings.append(u'\n%s: %s' % (self._cw._('i18n_by_author_field'),