Re: [PATCH v4 1/9] submodule: add a print_config_from_gitmodules() helper

[Antonio Ospite <ao2@ao2.it>]

On Fri, 24 Aug 2018 16:32:38 +0200
Ævar Arnfjörð Bjarmason <avarab@gmail.com> wrote:

> 
> On Fri, Aug 24 2018, Antonio Ospite wrote:
[...]
> > +static int config_print_callback(const char *key_, const char *value_, void *cb_data)
> > +{
> > +	char *key = cb_data;
> > +
> > +	if (!strcmp(key, key_))
> > +		printf("%s\n", value_);
> > +
> > +	return 0;
> > +}
> 
> No problem with the code itself, but I'd find this a lot easier to read
> in context if it was:
> 
>     key_ -> var
>     value_ -> value
>     key -> wanted_key, perhaps?
> 
> I.e. the rest of the file uses the convention of the
> config_from_gitmodules callbacks getting "var" and "value",
> respectively.
> 
> We don't use this convention of suffixing variables with "_" if they're
> arguments to the function anywhere else.
>

I was new to git when I firstly wrote the code, I picked up the style
by copying from builtin/config.c (collect_config() and
show_all_config()) because I was focusing more on the functionality and
didn't bother to harmonize the style with the destination file.

> > +int print_config_from_gitmodules(const char *key)
> > +{
> > +	int ret;
> > +	char *store_key;
> > +
> > +	ret = git_config_parse_key(key, &store_key, NULL);
> > +	if (ret < 0)
> > +		return CONFIG_INVALID_KEY;
> 
> Isn't this a memory leak? I.e. we should free() and return here, no?
>

It is true that git_config_parse_key_1() allocates some storage even
for an invalid key, and uses the space to lowercase the key as the
parsing progresses, however it also frees the memory in the *error*
path.

So unless I am missing something I don't think there is a leak here.

[...]
> > diff --git a/submodule-config.h b/submodule-config.h
> > index dc7278eea4..ed40e9a478 100644
> > --- a/submodule-config.h
> > +++ b/submodule-config.h
> > @@ -56,6 +56,8 @@ void submodule_free(struct repository *r);
> >   */
> >  int check_submodule_name(const char *name);
> >
> > +int print_config_from_gitmodules(const char *key);
> > +
> >  /*
> >   * Note: these helper functions exist solely to maintain backward
> >   * compatibility with 'fetch' and 'update_clone' storing configuration in
> 
> Another style nit: Makes more sense to put this new function right
> underneath "submodule_free" above, instead of under 1/2 of the functions
> that have a big comment describing how they work, since that comment
> doesn't apply to this new function.

You are probably right, IIRC the function was firstly written before
check_submodule_name() was there. And I didn't think of moving it up
when I rebased after check_submodule_name() was added.

Your same remark may apply to the new function added in patch 02.

I'll wait for other comments to see if a v5 is really needed.

Thanks for the review Ævar.

Ciao,
   Antonio

-- 
Antonio Ospite
https://ao2.it
https://twitter.com/ao2it

A: Because it messes up the order in which people normally read text.
   See http://en.wikipedia.org/wiki/Posting_style
Q: Why is top-posting such a bad thing?