shallow: add repository argument to set_alternate_shallow_file

Add a repository argument to allow callers of set_alternate_shallow_file
to be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

commit.h

@@ -199,7 +199,8 @@ extern struct commit_list *get_shallow_commits(struct object_array *heads,
 		int depth, int shallow_flag, int not_shallow_flag);
 extern struct commit_list *get_shallow_commits_by_rev_list(
 		int ac, const char **av, int shallow_flag, int not_shallow_flag);
-extern void set_alternate_shallow_file(const char *path, int override);
+#define set_alternate_shallow_file(r, p, o) set_alternate_shallow_file_##r(p, o)
+extern void set_alternate_shallow_file_the_repository(const char *path, int override);
 extern int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
 				 const struct oid_array *extra);
 extern void setup_alternate_shallow(struct lock_file *shallow_lock,

environment.c

@@ -189,7 +189,7 @@ void setup_git_env(const char *git_dir)
 	git_namespace = expand_namespace(getenv(GIT_NAMESPACE_ENVIRONMENT));
 	shallow_file = getenv(GIT_SHALLOW_FILE_ENVIRONMENT);
 	if (shallow_file)
-		set_alternate_shallow_file(shallow_file, 0);
+		set_alternate_shallow_file(the_repository, shallow_file, 0);
 }
 
 int is_bare_repository(void)

git.c

@@ -207,7 +207,7 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 		} else if (!strcmp(cmd, "--shallow-file")) {
 			(*argv)++;
 			(*argc)--;
-			set_alternate_shallow_file((*argv)[0], 1);
+			set_alternate_shallow_file(the_repository, (*argv)[0], 1);
 			if (envchanged)
 				*envchanged = 1;
 		} else if (!strcmp(cmd, "-C")) {

shallow.c

@@ -19,7 +19,7 @@ static int is_shallow = -1;
 static struct stat_validity shallow_stat;
 static char *alternate_shallow_file;
 
-void set_alternate_shallow_file(const char *path, int override)
+void set_alternate_shallow_file_the_repository(const char *path, int override)
 {
 	if (is_shallow != -1)
 		die("BUG: is_repository_shallow must not be called before set_alternate_shallow_file");