[MERGE][BUG #177809] bzr SOURCE DESTINATION tweaks

[Alexander Belchenko]

Spencer Chastain пишет:
> The main problem with the UI, particularly as it relates to the mv command,
> is that it is not clear to the user what has and  what has not happened.
> 
> Commands either succeed or they don't.  In the situations that they don't
> succeed, they typically (that is to say, in my experience) fail in one of
> two ways:

I need to say that your expectation is not correct re Bazaar.
Bazaar follows Python's paradigm EAFP (Easier to Ask Forgiveness than Permission).
So it's do what user say until errors encountered. At the point of error
Bazaar stops and complains about error loudly.

Per example when user run `bzr push url-to-server` but operation fails in
some way one ends up with incomplete branch on the server.

So I'd say mv command is also follows this model. It try to move files
and breaks at first error.

The real bug in Bazaar it's the fact the report about already moved files
is not appear on the screen when error occurs. It's bad. It's really bad
and undesirable. So my comment is all about this point.

> 1.  When the command exits, nothing has changed from before the command was
> issued
> 2.  The command continues to execute and reports errors as they occur -
> while also reporting successes as they occur under normal successful
> operation.