[PATCH/RFC] The new IncludeIf facility doesn't DWIM when the repo is symlinked

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

I have a ~/git_tree in my homedir that's symlinked to an external
drive, and doing "gitdir:~/git_tree/" doesn't work, because instead of
matching against ~/git_tree it's matched against
/mnt/some-other-storage/.

Here's a WIP patch that makes this work for me, any reason I shouldn't
finish this up & that we shouldn't be doing this? The doc don't say
"we'll only match gitdir against the absolute resolved path" or
anything like that, so until I checked out the implementation I didn't
realize what was going on:

diff --git a/config.c b/config.c
index b4a3205da3..606acaa3f1 100644
--- a/config.c
+++ b/config.c
@@ -214,6 +214,7 @@ static int include_by_gitdir(const struct
config_options *opts,
        struct strbuf pattern = STRBUF_INIT;
        int ret = 0, prefix;
        const char *git_dir;
+       int tried_absolute = 0;

        if (opts->git_dir)
                git_dir = opts->git_dir;
@@ -226,6 +227,7 @@ static int include_by_gitdir(const struct
config_options *opts,
        strbuf_add(&pattern, cond, cond_len);
        prefix = prepare_include_condition_pattern(&pattern);

+again:
        if (prefix < 0)
                goto done;

@@ -245,6 +247,12 @@ static int include_by_gitdir(const struct
config_options *opts,
        ret = !wildmatch(pattern.buf + prefix, text.buf + prefix,
                         icase ? WM_CASEFOLD : 0, NULL);

+       if (!ret && !tried_absolute) {
+               tried_absolute = 1;
+               strbuf_reset(&text);
+               strbuf_add_absolute_path(&text, git_dir);
+               goto again;
+       }
 done:
        strbuf_release(&pattern);
        strbuf_release(&text);