Re: [PATCH 2/3] config: fix case sensitive subsection names on writing

>
> Stefan Beller <sbeller@google.com> writes:
>
> > A use reported a submodule issue regarding strange case indentation
> > issues, but it could be boiled down to the following test case:
>
> Perhaps
>
> s/use/user/
> s/case indentation issues/section mix-up/

>
> > ... However we do not have a test for writing out config correctly with
> > case sensitive subsection names, which is why this went unnoticed in
> > 6ae996f2acf (git_config_set: make use of the config parser's event
> > stream, 2018-04-09)
>
> s/unnoticed in \(.*04-09)\)/unnoticed when \1 broke it./
>
> This is why I asked if the patch is a "FIX" for an issue introduced
> by the cited commit.

> >  static int get_base_var(struct strbuf *name)
> >  {
> > +     cf->section_name_old_dot_style = 1;
> >       for (;;) {
> >               int c = get_next_char();
> >               if (cf->eof)
>
> OK, let me rephrase.  The basic parse structure is that
>
>  * upon seeing '[', we call get_base_var(), which stuffs the
>    "section" (including subsection, if exists) in the strbuf.
>
>  * get_base_var() upon seeing a space after "[section ", calls
>    get_extended_base_var().  This space can never exist in an
>    old-style three-level names, where it is spelled as
>    "[section.subsection]".  This space cannot exist in two-level
>    names, either.  The closing ']' is eaten by this function before
>    it returns.
>
>  * get_extended_base_var() grabs the "double quoted" subsection name
>    and eats the closing ']' before it returns.
>
> So you set the new bit (section_name_old_dot_style) at the beginning
> of get_base_var(), i.e. declare that you assume we are reading old
> style, but upon entering get_extended_base_var(), unset it, because
> now you know we are parsing a modern style three-level name(s).
>
> Feels quite sensible way to keep track of old/new styles.
>
> When parsing two-level names, old-style bit is set, which we may
> need to be careful, thoguh.

> > -                     !strncasecmp(cf->var.buf, store->key, store->baselen);
> > +                     !cmpfn(cf->var.buf, store->key, store->baselen);
>
> OK.  Section names should still be case insensitive (only the case
> sensitivity of subsection names is special), but presumably that's
> already normalized by the caller so we do not have to worry when we
> use strncmp()?  Can we add a test to demonstrate that it works
> correctly?