rev-parse: respect core.hooksPath in --git-path

The idea of the --git-path option is not only to avoid having to
prefix paths with the output of --git-dir all the time, but also to
respect overrides for specific common paths inside the .git directory
(e.g. `git rev-parse --git-path objects` will report the value of the
environment variable GIT_OBJECT_DIRECTORY, if set).

When introducing the core.hooksPath setting, we forgot to adjust
git_path() accordingly. This patch fixes that.

While at it, revert the special-casing of core.hooksPath in
run-command.c, as it is now no longer needed.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

path.c

@@ -379,6 +379,8 @@ static void adjust_git_path(struct strbuf *buf, int git_dir_len)
 			      get_index_file(), strlen(get_index_file()));
 	else if (git_db_env && dir_prefix(base, "objects"))
 		replace_dir(buf, git_dir_len + 7, get_object_directory());
+	else if (git_hooks_path && dir_prefix(base, "hooks"))
+		replace_dir(buf, git_dir_len + 5, git_hooks_path);
 	else if (git_common_dir_env)
 		update_common_dir(buf, git_dir_len, NULL);
 }

run-command.c

@@ -815,10 +815,7 @@ const char *find_hook(const char *name)
 	static struct strbuf path = STRBUF_INIT;
 
 	strbuf_reset(&path);
-	if (git_hooks_path)
-		strbuf_addf(&path, "%s/%s", git_hooks_path, name);
-	else
-		strbuf_git_path(&path, "hooks/%s", name);
+	strbuf_git_path(&path, "hooks/%s", name);
 	if (access(path.buf, X_OK) < 0)
 		return NULL;
 	return path.buf;

t/t1350-config-hooks-path.sh

@@ -34,4 +34,10 @@ test_expect_success 'Check that various forms of specifying core.hooksPath work'
 	test_cmp expect actual
 '
 
+test_expect_success 'git rev-parse --git-path hooks' '
+	git config core.hooksPath .git/custom-hooks &&
+	git rev-parse --git-path hooks/abc >actual &&
+	test .git/custom-hooks/abc = "$(cat actual)"
+'
+
 test_done