Re: [PATCH v2] config: learn the "onbranch:" includeIf condition

>
> Currently, if a user wishes to have individual settings per branch, they
> are required to manually keep track of the settings in their head and
> manually set the options on the command-line or change the config at
> each branch.
>
> Teach config the "onbranch:" includeIf condition so that it can
> conditionally include configuration files if the branch that is checked
> out in the current worktree matches the pattern given.

> diff --git a/Documentation/config.txt b/Documentation/config.txt
> index 7e2a6f61f5..93aa4323c6 100644
> --- a/Documentation/config.txt
> +++ b/Documentation/config.txt
> @@ -144,6 +144,13 @@ refer to linkgit:gitignore[5] for details. For convenience:
>         This is the same as `gitdir` except that matching is done
>         case-insensitively (e.g. on case-insensitive file sytems)
>
> +`onbranch`::
> +       The data that follows the keyword `onbranch:` is taken to be a pattern
> +       with standard globbing wildcards and two additional ones, `**/` and
> +       `/**`, that can match multiple path components. If we are in a worktree
> +       where the name of the branch that is currently checked out matches the
> +       pattern, the include condition is met.

> @@ -264,6 +265,24 @@ static int include_by_gitdir(const struct config_options *opts,
>         return ret;
>  }
>
> +static int include_by_branch(const char *cond, size_t cond_len)
> +{
> +       int flags;
> +       int ret;
> +       struct strbuf pattern = STRBUF_INIT;
> +       const char *refname = resolve_ref_unsafe("HEAD", 0, NULL, &flags);
> +       const char *shortname;
> +
> +       if (!refname || !(flags & REF_ISSYMREF) ||
> +                       !skip_prefix(refname, "refs/heads/", &shortname))

> +               return 0;
> +
> +       strbuf_add(&pattern, cond, cond_len);
> +       ret = !wildmatch(pattern.buf, shortname, WM_PATHNAME);
> +       strbuf_release(&pattern);
> +       return ret;
> +}