get lock is possible only once

[Mumpitzstuff]

It seems to be a bug that you get the locking dialog only once. The following steps are needed to reproduce the problem:

1.) open a locked file
2.) try to edit something until you get the locking dialog
3.) Cancel the locking dialog
4.) try to edit something again and no locking dialog appears anymore
5.) close the file and reopen it
6.) try to edit the file and you get the dialog again

It would be a nice feature if it would be possible to make some local changes without getting a lock. Sometimes it is really useful.