Allow push and fetch urls to be different

This introduces a config setting remote.$remotename.pushurl which is
used for pushes only. If absent remote.$remotename.url is used for
pushes and fetches as before.
This is useful, for example, in order to do passwordless fetches
(remote update) over the git transport but pushes over ssh.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: Michael J Gruber

Documentation/config.txt

@@ -1319,6 +1319,9 @@ remote.<name>.url::
 	The URL of a remote repository.  See linkgit:git-fetch[1] or
 	linkgit:git-push[1].
 
+remote.<name>.pushurl::
+	The push URL of a remote repository.  See linkgit:git-push[1].
+
 remote.<name>.proxy::
 	For remotes that require curl (http, https and ftp), the URL to
 	the proxy to use for that remote.  Set to the empty string to

Documentation/urls-remotes.txt

@@ -27,10 +27,13 @@ config file would appear like this:
 ------------
 	[remote "<name>"]
 		url = <url>
+		pushurl = <pushurl>
 		push = <refspec>
 		fetch = <refspec>
 ------------
 
+The `<pushurl>` is used for pushes only. It is optional and defaults
+to `<url>`.
 
 Named file in `$GIT_DIR/remotes`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

builtin-push.c

@@ -117,6 +117,8 @@ static int do_push(const char *repo, int flags)
 {
 	int i, errs;
 	struct remote *remote = remote_get(repo);
+	const char **url;
+	int url_nr;
 
 	if (!remote) {
 		if (repo)
@@ -152,9 +154,16 @@ static int do_push(const char *repo, int flags)
 			setup_default_push_refspecs();
 	}
 	errs = 0;
-	for (i = 0; i < remote->url_nr; i++) {
+	if (remote->pushurl_nr) {
+		url = remote->pushurl;
+		url_nr = remote->pushurl_nr;
+	} else {
+		url = remote->url;
+		url_nr = remote->url_nr;
+	}
+	for (i = 0; i < url_nr; i++) {
 		struct transport *transport =
-			transport_get(remote, remote->url[i]);
+			transport_get(remote, url[i]);
 		int err;
 		if (receivepack)
 			transport_set_option(transport,
@@ -163,14 +172,14 @@ static int do_push(const char *repo, int flags)
 			transport_set_option(transport, TRANS_OPT_THIN, "yes");
 
 		if (flags & TRANSPORT_PUSH_VERBOSE)
-			fprintf(stderr, "Pushing to %s\n", remote->url[i]);
+			fprintf(stderr, "Pushing to %s\n", url[i]);
 		err = transport_push(transport, refspec_nr, refspec, flags);
 		err |= transport_disconnect(transport);
 
 		if (!err)
 			continue;
 
-		error("failed to push some refs to '%s'", remote->url[i]);
+		error("failed to push some refs to '%s'", url[i]);
 		errs++;
 	}
 	return !!errs;

remote.c

@@ -106,6 +106,12 @@ static void add_url_alias(struct remote *remote, const char *url)
 	add_url(remote, alias_url(url));
 }
 
+static void add_pushurl(struct remote *remote, const char *pushurl)
+{
+	ALLOC_GROW(remote->pushurl, remote->pushurl_nr + 1, remote->pushurl_alloc);
+	remote->pushurl[remote->pushurl_nr++] = pushurl;
+}
+
 static struct remote *make_remote(const char *name, int len)
 {
 	struct remote *ret;
@@ -379,6 +385,11 @@ static int handle_config(const char *key, const char *value, void *cb)
 		if (git_config_string(&v, key, value))
 			return -1;
 		add_url(remote, v);
+	} else if (!strcmp(subkey, ".pushurl")) {
+		const char *v;
+		if (git_config_string(&v, key, value))
+			return -1;
+		add_pushurl(remote, v);
 	} else if (!strcmp(subkey, ".push")) {
 		const char *v;
 		if (git_config_string(&v, key, value))
@@ -424,6 +435,9 @@ static void alias_all_urls(void)
 		for (j = 0; j < remotes[i]->url_nr; j++) {
 			remotes[i]->url[j] = alias_url(remotes[i]->url[j]);
 		}
+		for (j = 0; j < remotes[i]->pushurl_nr; j++) {
+			remotes[i]->pushurl[j] = alias_url(remotes[i]->pushurl[j]);
+		}
 	}
 }
 

remote.h

@@ -15,6 +15,10 @@ struct remote {
 	int url_nr;
 	int url_alloc;
 
+	const char **pushurl;
+	int pushurl_nr;
+	int pushurl_alloc;
+
 	const char **push_refspec;
 	struct refspec *push;
 	int push_refspec_nr;