# HG changeset patch
# User Philippe Pepiot <philippe.pepiot@logilab.fr>
# Date 1493365777 -7200
# Node ID af5d0a3c3f1aed458341ac167d8be1cc58b4404b
# Parent  50109859da4381206459adf67386e3a8c0286d4c
[req] fix find() generating non-rewritable rql on non final relations

When filtering on a relation, find() was generating rql like
'Any X WHERE X is ETYPE, X relation EID' which work without being rewritten (it
should probably not), but when applying some rewrite (eg. permissions) it raise
in rqlrewrite code.

	def _use_orig_term(self, snippet_varname, term):
			...
	>       self.rewritten[key] = term.name
	E       AttributeError: 'Constant' object has no attribute 'name'


Generate valid rql instead 'Any X WHERE X is ETYPE, X relation Y, Y eid EID'.

diff -r 50109859da43 -r af5d0a3c3f1a cubicweb/req.py
--- a/cubicweb/req.py	Wed Apr 26 15:04:40 2017 +0200
+++ b/cubicweb/req.py	Fri Apr 28 09:49:37 2017 +0200
@@ -229,9 +229,14 @@
                 parts.append('{var} {attr} X, {var} eid %(reverse_{attr})s'.format(
                     var=next(varmaker), attr=attr))
             else:
-                if attr not in eschema.subjrels:
+                rel = eschema.subjrels.get(attr)
+                if rel is None:
                     raise KeyError('{0} not in {1} subject relations'.format(attr, eschema))
-                parts.append('X {attr} %({attr})s'.format(attr=attr))
+                if rel.final:
+                    parts.append('X {attr} %({attr})s'.format(attr=attr))
+                else:
+                    parts.append('X {attr} {var}, {var} eid %({attr})s'.format(
+                        attr=attr, var=next(varmaker)))
 
         rql = ', '.join(parts)
 
diff -r 50109859da43 -r af5d0a3c3f1a cubicweb/test/unittest_req.py
--- a/cubicweb/test/unittest_req.py	Wed Apr 26 15:04:40 2017 +0200
+++ b/cubicweb/test/unittest_req.py	Fri Apr 28 09:49:37 2017 +0200
@@ -132,7 +132,10 @@
                 firstname=u'adrien',
                 in_group=req.find('CWGroup', name=u'users').one())
 
-            u = req.find('CWUser', login=u'cdevienne').one()
+            rset = req.find('CWUser', login=u'cdevienne')
+            self.assertEqual(rset.printable_rql(),
+                             'Any X WHERE X is CWUser, X login "cdevienne"')
+            u = rset.one()
             self.assertEqual(u.firstname, u"Christophe")
 
             users = list(req.find('CWUser').entities())
@@ -143,8 +146,11 @@
             self.assertEqual(len(groups), 1)
             self.assertEqual(groups[0].name, u'users')
 
-            users = req.find('CWUser', in_group=groups[0]).entities()
-            users = list(users)
+            rset = req.find('CWUser', in_group=groups[0])
+            self.assertEqual(rset.printable_rql(),
+                             'Any X WHERE X is CWUser, X in_group A, '
+                             'A eid {0}'.format(groups[0].eid))
+            users = list(rset.entities())
             self.assertEqual(len(users), 2)
 
             with self.assertRaisesRegexp(