Comment 1 for bug 1302106

Looks like OpenLDAP accepts a search filter like "(cn=Doe, John)". It also accepts "(cn=Doe\\2c\\20John)"

I also tried this with an active directory server and it didn't have a problem with the escaped or unescaped filter:

$ ldapsearch -LLL -s one -b "cn=Users,dc=cfs1,dc=us" "(cn=Doe, John)" cn
dn: CN=Doe\, John,CN=Users,DC=cfs1,DC=us
cn: Doe, John

$ ldapsearch -LLL -s one -b "cn=Users,dc=cfs1,dc=us" "(cn=Doe\\2c\\20John)" cn
dn: CN=Doe\, John,CN=Users,DC=cfs1,DC=us
cn: Doe, John

Maybe there's different versions of AD that accept a ',' in the filter or not.

It actually looks like the error is coming from the python-ldap library and not from the server.