SYSDB: User and group renames

[Jakub Hrozek]

The attached patch fixes a regression in the local domain tools where
sss_groupadd no longer detected a GID duplicate. The check for EEXIST is
moved one level up into more high level function.

The patch also adds the same rename support for users. I found it odd
that we allowed a rename of groups but not users. There is a catch when
storing a user -- his cached password would be gone. I think that
renaming a user is such a rare operation that it's not severe, plus
there is a warning in the logs.

Unit test was amended, too.

[Stephen Gallagher]

On Fri, 2012-05-11 at 17:45 +0200, Jakub Hrozek wrote:
>  The attached patch fixes a regression in the local domain tools
> where
>  sss_groupadd no longer detected a GID duplicate. The check for EEXIST is
>  moved one level up into more high level function.
>  
>  The patch also adds the same rename support for users. I found it odd
>  that we allowed a rename of groups but not users. There is a catch when
>  storing a user -- his cached password would be gone. I think that
>  renaming a user is such a rare operation that it's not severe, plus
>  there is a warning in the logs.
>  
>  Unit test was amended, too. 
Ack for master and sssd-1-8.

[Stephen Gallagher]

On Fri, 2012-05-11 at 12:16 -0400, Stephen Gallagher wrote:
>  On Fri, 2012-05-11 at 17:45 +0200, Jakub Hrozek wrote:
>  > The attached patch fixes a regression in the local domain tools where
>  > sss_groupadd no longer detected a GID duplicate. The check for EEXIST is
>  > moved one level up into more high level function.
>  > 
>  > The patch also adds the same rename support for users. I found it odd
>  > that we allowed a rename of groups but not users. There is a catch when
>  > storing a user -- his cached password would be gone. I think that
>  > renaming a user is such a rare operation that it's not severe, plus
>  > there is a warning in the logs.
>  > 
>  > Unit test was amended, too.
>  
>  Ack for master and sssd-1-8. 
Pushed to master and sssd-1-8.