[patch] make 'bzr ignore' take multiple arguments (bug 29488)

[Michele Cella]

Cheuksan Edward Wang wrote:
> -    def run(self, name_pattern=None, old_default_rules=None):
> +    def run(self, name_pattern_list=None, old_default_rules=None):
>          from bzrlib.atomicfile import AtomicFile
>          if old_default_rules is not None:
>              # dump the rules and exit
>              for pattern in ignores.OLD_DEFAULTS:
>                  print pattern
>              return
> -        if name_pattern is None:
> -            raise errors.BzrCommandError("ignore requires a NAME_PATTERN")
> +        if name_pattern_list is None or name_pattern_list == []:
> +            raise errors.BzrCommandError("ignore requires at least one "
> +                                  "NAME_PATTERN or --old-default-rules")

Hi Edward,

It seems you're just trying to check for an empty list here.

Since in python every empty sequence (a list, a dictionary and a tuple) 
evaluates to False (as does None BTW) you don't need this long check but 
just:

if not name_pattern_list:
     raise errors.BzrCommandError("ignore requires at least one "
                                  "NAME_PATTERN or --old-default-rules")

in fact:

 >>> def run(pattern=None):
...     if not pattern:
...             print "Error"
...     else:
...             print "Ok"
...
 >>> run()
Error
 >>> run(None)
Error
 >>> run([])
Error
 >>> run([1, 2, 3])
Ok
 >>>

This also saves instantiating an empty list just for making the 
comparison (not a big save of course).

Ciao
Michele