Bug#175710: python-ldap modlist patch

[Michael Ströder]

Michael Ströder wrote:
> I will check whether it's feasible to filter() old_value. I had some 
> problems with broken iPlanet DS 5.1 (prior SP1) which returned [] as 
> attribute value in search results.
> 
> Additionally I've learned in the mean-time that some attributes might 
> hold empty strings (e.g. attributes of DirectoryString syntax). 
> Therefore using filter(None,valuelist) might be problematic anyway and 
> might be dropped completely from modifyModList().
> => you're safe if your code leaves out non-existent attributes completely.

I've checked in a new version with the following change:

-------------------------- snip --------------------------
ldap.modlist:
* modifyModlist(): Only None is filtered from attribute value lists,
   '' is preserved as valid attribute value. But filtering applies
   to old_value and new_value now.
-------------------------- snip --------------------------

Please test!

Ciao, Michael.