On Wed, Jul 03, 2013 at 10:02:34AM +0200, Michael Haggerty wrote:
> On 07/03/2013 12:21 AM, Junio C Hamano wrote:
> > Ramkumar Ramachandra <artagnon@xxxxxxxxx> writes:
> >
> >>> def get(self, name, default=''):
> >>> try:
> >>> values = self._split(read_git_output(
> >>> ['config', '--get', '--null', '%s.%s' % (self.section, name)],
> >>> env=self.env, keepends=True,
> >>> ))
> >>
> >> Wait, what is the point of using --null and then splitting by hand
> >> using a poorly-defined static method? Why not drop the --null and
> >> splitlines() as usual?
> >
> > You may actually have spotted a bug or misuse of "--get" here.
> >
> > With this sample configuration:
> >
> > $ cat >sample <<\EOF
> > [a]
> > one = value
> > one = another
> >
> > [b]
> > one = "value\nanother"
> > EOF
> >
> > A script cannot differentiate between them without using '--null'.
> >
> > $ git config -f sample --get-all a.one
> > $ git config -f sample --get-all b.one
> >
> > But that matters only when you use "--get-all", not "--get". If
> > this method wants to make sure that the user did not misuse a.one
> > as a multi-valued configuration variable, use of "--null --get-all"
> > followed by checking how many items the command gives you back would
> > be a way to do so.
>
> No, the code in question was a simple sanity check (i.e., mostly a check
> of my own sanity and understanding of "git config" behavior) preceding
> the information-losing next line "return values[0]". If it had been
> meant as a check that the user hadn't misconfigured the system, then I
> wouldn't have used assert but rather raised a ConfigurationException
> with an explanatory message.
>
> I would be happy to add the checking that you described, but I didn't
> have the impression that it is the usual convention. Does code that
> wants a single value from the config usually verify that there is
> one-and-only-one value, or does it typically just do the equivalent of
> "git config --get" and use the returned (effectively the last) value?
Doesn't "git config --get" return an error if there are multiple values?
The answer is apparently "no" - I wrote the text below from
git-config(1) and then checked the behaviour. This seems to be a
regression in git-config (bisect running now).
I think the "correct" answer is what's below, but it doesn't work like
this in current Git:
If you want a single value then I think it's normal to just read the
output of "git config" and let it handle the error cases, without
needing to split the result at all.
I think there is a different issue in the "except" block following
the code quoted at the top though - you will return "default" if a
key happens to be multi-valued. The script should check the return
code and raise a ConfigurationException if it is 2.
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