fakeldap.py: Don't rely on KeyError exceptions when accessing non-existent keys of MockLDAP.directory.

 The implementation of the internal MockLDAP.directory dictionary is
 defined via

    self.directory = defaultdict(lambda: {})

 This results in a dictionary that always returns an empty dict for any
 key requested:

    >>> print (self.directory['some_key'])
    {}

 Thus, we cannot rely on the raisal of KeyError exceptions when accessing
 a non-existing LDAP DNs in the MockLDAP.directory.

 Instead, we check if MockLDAP.directory['some_key'] returns an empty
 dict {} value.

Author: sunweaver

fakeldap.py

@@ -294,9 +294,8 @@ def _compare_s(self, dn, attr, value):
         return found and 1 or 0
 
     def _modify_s(self, dn, mod_attrs):
-        try:
-            entry = self.directory[dn]
-        except KeyError:
+        entry = self.directory[dn]
+        if entry == {}:
             raise ldap.NO_SUCH_OBJECT
 
         for item in mod_attrs:
@@ -325,9 +324,8 @@ def _modify_s(self, dn, mod_attrs):
         return (103, [])
 
     def _rename_s(self, dn, newdn):
-        try:
-            entry = self.directory[dn]
-        except KeyError:
+        entry = self.directory[dn]
+        if entry == {}:
             raise ldap.NO_SUCH_OBJECT
 
         changes = newdn.split('=')
@@ -384,10 +382,9 @@ def _add_s(self, dn, record):
         for item in record:
             entry[item[0]] = item[1]
         logger.debug("entry: %s".format(entry))
-        try:
-            self.directory[dn]
+        if self.directory[dn] != {}:
             raise ldap.ALREADY_EXISTS
-        except KeyError:
+        else:
             self.directory[dn] = entry
             return (105,[], len(self.calls), [])