submodule-config: add skip_if_read option to repo_read_gitmodules()

Currently, submodule-config.c doesn't have an externally accessible
function to read gitmodules only if it wasn't already read. But this
exact behavior is internally implemented by gitmodules_read_check(), to
perform a lazy load. Let's merge this function with
repo_read_gitmodules() adding a 'skip_if_read' which allows both
internal and external callers to access this functionality. This
simplifies a little the code. The added option will also be used in
the following patch.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

4 files changed, 10 insertions, 16 deletions

diff --git a/builtin/grep.c b/builtin/grep.c
index 4a436d6c99..d3ed05c1da 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -420,7 +420,7 @@ static int grep_submodule(struct grep_opt *opt,
 		return 0;
 	}
 
-	repo_read_gitmodules(&subrepo);
+	repo_read_gitmodules(&subrepo, 0);
 
 	/*
 	 * NEEDSWORK: This adds the submodule's object directory to the list of
diff --git a/submodule-config.c b/submodule-config.c
index 85064810b2..bd5e14ab20 100644
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -674,10 +674,13 @@ static int gitmodules_cb(const char *var, const char *value, void *data)
 	return parse_config(var, value, &parameter);
 }
 
-void repo_read_gitmodules(struct repository *repo)
+void repo_read_gitmodules(struct repository *repo, int skip_if_read)
 {
 	submodule_cache_check_init(repo);
 
+	if (repo->submodule_cache->gitmodules_read && skip_if_read)
+		return;
+
 	if (repo_read_index(repo) < 0)
 		return;
 
@@ -703,20 +706,11 @@ void gitmodules_config_oid(const struct object_id *commit_oid)
 	the_repository->submodule_cache->gitmodules_read = 1;
 }
 
-static void gitmodules_read_check(struct repository *repo)
-{
-	submodule_cache_check_init(repo);
-
-	/* read the repo's .gitmodules file if it hasn't been already */
-	if (!repo->submodule_cache->gitmodules_read)
-		repo_read_gitmodules(repo);
-}
-
 const struct submodule *submodule_from_name(struct repository *r,
 					    const struct object_id *treeish_name,
 		const char *name)
 {
-	gitmodules_read_check(r);
+	repo_read_gitmodules(r, 1);
 	return config_from(r->submodule_cache, treeish_name, name, lookup_name);
 }
 
@@ -724,7 +718,7 @@ const struct submodule *submodule_from_path(struct repository *r,
 					    const struct object_id *treeish_name,
 		const char *path)
 {
-	gitmodules_read_check(r);
+	repo_read_gitmodules(r, 1);
 	return config_from(r->submodule_cache, treeish_name, path, lookup_path);
 }
 
diff --git a/submodule-config.h b/submodule-config.h
index 42918b55e8..c11e22cf50 100644
--- a/submodule-config.h
+++ b/submodule-config.h
@@ -61,7 +61,7 @@ int option_fetch_parse_recurse_submodules(const struct option *opt,
 					  const char *arg, int unset);
 int parse_update_recurse_submodules_arg(const char *opt, const char *arg);
 int parse_push_recurse_submodules_arg(const char *opt, const char *arg);
-void repo_read_gitmodules(struct repository *repo);
+void repo_read_gitmodules(struct repository *repo, int skip_if_read);
 void gitmodules_config_oid(const struct object_id *commit_oid);
 
 /**
diff --git a/unpack-trees.c b/unpack-trees.c
index 2399b6818b..f5a8051803 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -291,11 +291,11 @@ static void load_gitmodules_file(struct index_state *index,
 	if (pos >= 0) {
 		struct cache_entry *ce = index->cache[pos];
 		if (!state && ce->ce_flags & CE_WT_REMOVE) {
-			repo_read_gitmodules(the_repository);
+			repo_read_gitmodules(the_repository, 0);
 		} else if (state && (ce->ce_flags & CE_UPDATE)) {
 			submodule_free(the_repository);
 			checkout_entry(ce, state, NULL, NULL);
-			repo_read_gitmodules(the_repository);
+			repo_read_gitmodules(the_repository, 0);
 		}
 	}
 }