urlmatch.[ch]: add and use URLMATCH_CONFIG_INIT

Change the initialization pattern of "struct urlmatch_config" to use
an *_INIT macro and designated initializers. Right now there's no
other "struct" member of "struct urlmatch_config" which would require
its own *_INIT, but it's good practice not to assume that. Let's also
change this to a designated initializer while we're at it.

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

Author: avar

builtin/config.c

@@ -575,7 +575,7 @@ static int get_urlmatch(const char *var, const char *url)
 	int ret;
 	char *section_tail;
 	struct string_list_item *item;
-	struct urlmatch_config config = { STRING_LIST_INIT_DUP };
+	struct urlmatch_config config = URLMATCH_CONFIG_INIT;
 	struct string_list values = STRING_LIST_INIT_DUP;
 
 	config.collect_fn = urlmatch_collect_fn;

credential.c

@@ -105,7 +105,7 @@ static int match_partial_url(const char *url, void *cb)
 static void credential_apply_config(struct credential *c)
 {
 	char *normalized_url;
-	struct urlmatch_config config = { STRING_LIST_INIT_DUP };
+	struct urlmatch_config config = URLMATCH_CONFIG_INIT;
 	struct strbuf url = STRBUF_INIT;
 
 	if (!c->host)

http.c

@@ -990,7 +990,7 @@ void http_init(struct remote *remote, const char *url, int proactive_auth)
 	char *low_speed_limit;
 	char *low_speed_time;
 	char *normalized_url;
-	struct urlmatch_config config = { STRING_LIST_INIT_DUP };
+	struct urlmatch_config config = URLMATCH_CONFIG_INIT;
 
 	config.section = "http";
 	config.key = NULL;

urlmatch.h

@@ -66,6 +66,10 @@ struct urlmatch_config {
 	int (*fallback_match_fn)(const char *url, void *cb);
 };
 
+#define URLMATCH_CONFIG_INIT { \
+	.vars = STRING_LIST_INIT_DUP, \
+}
+
 int urlmatch_config_entry(const char *var, const char *value, void *cb);
 
 #endif /* URL_MATCH_H */