Bug 9484: userid not generated consistently (different editing pages)

Bug 9484: userid not generated consistently (different editing pages)

When modifying a patron through different pages, the userid
generation does not behave always the same way; this patch
corrects this:
- when firstname and surname are present in the form, they
are used for the generation;
- if there are not in the form, the firstname and surname
in database are used instead.

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Comment: Work as described. No errors.
Test
This patch lacks a test plan, so I do the following
1) New user, empty userid, autocompleted
2) Edit user, change userid, saved correctly
3) Edit user, main edit window, emptied userid, autocompleted
4) Edit user, Detail > Library use, emptied userid, not autocomplete (not even a dot)
5) Applied patch
6) Repeated 1-3, same behavior
7) Repeated 4), now autocompletes with same userid as 3)

So, works as described.
No koha-qa errors.

NOTE: It's impossible now to delete userid from interface.

Off-topic: tried an userid in Arabic, works very well.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>