submodule API: don't handle SM_..{UNSPECIFIED,COMMAND} in to_string()

Change the submodule_strategy_to_string() function added in
3604242f080 (submodule: port init from shell to C, 2016-04-15) to
really return a "const char *". In the "SM_UPDATE_COMMAND" case it
would return a strbuf_detach().

Furthermore, this function would return NULL on SM_UPDATE_UNSPECIFIED,
so it wasn't safe to xstrdup() its return value in the general case,
or to use it in a sprintf() format as the code removed in the
preceding commit did.

But its callers would never call it with either SM_UPDATE_UNSPECIFIED
or SM_UPDATE_COMMAND. Let's have its behavior reflect how its only
user expects it to behave, and BUG() out on the rest.

By doing this we can also stop needlessly xstrdup()-ing and free()-ing
the memory for the config we're setting. We can instead always use
constant strings. We can also use the *_tmp() variant of
git_config_get_string().

Let's also rename this submodule_strategy_to_string() function to
submodule_update_type_to_string(). Now that it's only tasked with
returning a string version of the "enum submodule_update_type type".
Before it would look at the "command" field in "struct
submodule_update_strategy".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 5 insertions, 7 deletions

diff --git a/submodule.c b/submodule.c
index 3fa5db3ecd..1ebda30c50 100644
--- a/submodule.c
+++ b/submodule.c
@@ -415,10 +415,9 @@ int parse_submodule_update_strategy(const char *value,
 	return 0;
 }
 
-const char *submodule_strategy_to_string(const struct submodule_update_strategy *s)
+const char *submodule_update_type_to_string(enum submodule_update_type type)
 {
-	struct strbuf sb = STRBUF_INIT;
-	switch (s->type) {
+	switch (type) {
 	case SM_UPDATE_CHECKOUT:
 		return "checkout";
 	case SM_UPDATE_MERGE:
@@ -428,12 +427,11 @@ const char *submodule_strategy_to_string(const struct submodule_update_strategy
 	case SM_UPDATE_NONE:
 		return "none";
 	case SM_UPDATE_UNSPECIFIED:
-		return NULL;
 	case SM_UPDATE_COMMAND:
-		strbuf_addf(&sb, "!%s", s->command);
-		return strbuf_detach(&sb, NULL);
+		BUG("init_submodule() should handle type %d", type);
+	default:
+		BUG("unexpected update strategy type: %d", type);
 	}
-	return NULL;
 }
 
 void handle_ignore_submodules_arg(struct diff_options *diffopt,