http_init: accept separate URL parameter

The http_init function takes a "struct remote". Part of its
initialization procedure is to look at the remote's url and
grab some auth-related parameters. However, using the url
included in the remote is:

  - wrong; the remote-curl helper may have a separate,
    unrelated URL (e.g., from remote.*.pushurl). Looking at
    the remote's configured url is incorrect.

  - incomplete; http-fetch doesn't have a remote, so passes
    NULL. So http_init never gets to see the URL we are
    actually going to use.

  - cumbersome; http-push has a similar problem to
    http-fetch, but actually builds a fake remote just to
    pass in the URL.

Instead, let's just add a separate URL parameter to
http_init, and all three callsites can pass in the
appropriate information.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

http-push.c

@@ -1747,7 +1747,6 @@ int main(int argc, char **argv)
 	int i;
 	int new_refs;
 	struct ref *ref, *local_refs;
-	struct remote *remote;
 
 	git_extract_argv0_path(argv[0]);
 
@@ -1821,14 +1820,7 @@ int main(int argc, char **argv)
 
 	memset(remote_dir_exists, -1, 256);
 
-	/*
-	 * Create a minimum remote by hand to give to http_init(),
-	 * primarily to allow it to look at the URL.
-	 */
-	remote = xcalloc(sizeof(*remote), 1);
-	ALLOC_GROW(remote->url, remote->url_nr + 1, remote->url_alloc);
-	remote->url[remote->url_nr++] = repo->url;
-	http_init(remote);
+	http_init(NULL, repo->url);
 
 #ifdef USE_CURL_MULTI
 	is_running_queue = 0;