submodule--helper: get remote names from any repository

`get_default_remote()` retrieves the name of a remote by resolving the
refs from of the current repository's ref store.

Thus in order to use it for retrieving the remote name of a submodule,
we have to start a new subprocess which runs from the submodule
directory.

Let's instead introduce a function called `repo_get_default_remote()`
which takes any repository object and retrieves the remote accordingly.

`get_default_remote()` is then defined as a call to
`repo_get_default_remote()` with 'the_repository' passed to it.

Now that we have `repo_get_default_remote()`, we no longer have to start
a subprocess that called `submodule--helper get-default-remote` from
within the submodule directory.

So let's make a function called `get_default_remote_submodule()` which
takes a submodule path, and returns the default remote for that
submodule, all within the same process.

We can now use this function to save an unnecessary subprocess spawn in
`sync_submodule()`, and also in a subsequent patch, which will require
this functionality.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Shourya Shukla <periperidip@gmail.com>
Helped-by: Glen Choo <chooglen@google.com>
Signed-off-by: Atharva Raykar <raykar.ath@gmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index 77ca4270f4cdb49198e0a38077b29f3881c5bf0f..b5a2d83029bdf437ea419d9e069d12cb4d274009 100644 (file)
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -31,11 +31,13 @@
 typedef void (*each_submodule_fn)(const struct cache_entry *list_item,
                                  void *cb_data);
 
-static char *get_default_remote(void)
+static char *repo_get_default_remote(struct repository *repo)
 {
        char *dest = NULL, *ret;
        struct strbuf sb = STRBUF_INIT;
-       const char *refname = resolve_ref_unsafe("HEAD", 0, NULL, NULL);
+       struct ref_store *store = get_main_ref_store(repo);
+       const char *refname = refs_resolve_ref_unsafe(store, "HEAD", 0, NULL,
+                                                     NULL);
 
        if (!refname)
                die(_("No such ref: %s"), "HEAD");
@@ -48,7 +50,7 @@ static char *get_default_remote(void)
                die(_("Expecting a full ref name, got %s"), refname);
 
        strbuf_addf(&sb, "branch.%s.remote", refname);
-       if (git_config_get_string(sb.buf, &dest))
+       if (repo_config_get_string(repo, sb.buf, &dest))
                ret = xstrdup("origin");
        else
                ret = dest;
@@ -57,6 +59,19 @@ static char *get_default_remote(void)
        return ret;
 }
 
+static char *get_default_remote_submodule(const char *module_path)
+{
+       struct repository subrepo;
+
+       repo_submodule_init(&subrepo, the_repository, module_path, null_oid());
+       return repo_get_default_remote(&subrepo);
+}
+
+static char *get_default_remote(void)
+{
+       return repo_get_default_remote(the_repository);
+}
+
 static int print_default_remote(int argc, const char **argv, const char *prefix)
 {
        char *remote;
@@ -1343,9 +1358,8 @@ static void sync_submodule(const char *path, const char *prefix,
 {
        const struct submodule *sub;
        char *remote_key = NULL;
-       char *sub_origin_url, *super_config_url, *displaypath;
+       char *sub_origin_url, *super_config_url, *displaypath, *default_remote;
        struct strbuf sb = STRBUF_INIT;
-       struct child_process cp = CHILD_PROCESS_INIT;
        char *sub_config_path = NULL;
 
        if (!is_submodule_active(the_repository, path))
@@ -1384,21 +1398,15 @@ static void sync_submodule(const char *path, const char *prefix,
        if (!is_submodule_populated_gently(path, NULL))
                goto cleanup;
 
-       prepare_submodule_repo_env(&cp.env_array);
-       cp.git_cmd = 1;
-       cp.dir = path;
-       strvec_pushl(&cp.args, "submodule--helper",
-                    "print-default-remote", NULL);
-
        strbuf_reset(&sb);
-       if (capture_command(&cp, &sb, 0))
+       default_remote = get_default_remote_submodule(path);
+       if (!default_remote)
                die(_("failed to get the default remote for submodule '%s'"),
                      path);
 
-       strbuf_strip_suffix(&sb, "\n");
-       remote_key = xstrfmt("remote.%s.url", sb.buf);
+       remote_key = xstrfmt("remote.%s.url", default_remote);
+       free(default_remote);
 
-       strbuf_reset(&sb);
        submodule_to_gitdir(&sb, path);
        strbuf_addstr(&sb, "/config");