Add remote.<name>.proxy

As well as allowing a default http.proxy option, allow it to be set
per-remote.

Signed-off-by: Sam Vilain <sam.vilain@catalyst.net.nz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -552,7 +552,8 @@ access method.
 
 http.proxy::
 	Override the HTTP proxy, normally configured using the 'http_proxy'
-	environment variable (see gitlink:curl[1]).
+	environment variable (see gitlink:curl[1]).  This can be overridden
+	on a per-remote basis; see remote.<name>.proxy
 
 http.sslVerify::
 	Whether to verify the SSL certificate when fetching or pushing
@@ -702,6 +703,11 @@ remote.<name>.url::
 	The URL of a remote repository.  See gitlink:git-fetch[1] or
 	gitlink: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
+	disable proxying for that remote.
+
 remote.<name>.fetch::
 	The default set of "refspec" for gitlink:git-fetch[1]. See
 	gitlink:git-fetch[1].

remote.c

@@ -278,6 +278,8 @@ static int handle_config(const char *key, const char *value)
 	} else if (!strcmp(subkey, ".tagopt")) {
 		if (!strcmp(value, "--no-tags"))
 			remote->fetch_tags = -1;
+	} else if (!strcmp(subkey, ".proxy")) {
+		remote->http_proxy = xstrdup(value);
 	}
 	return 0;
 }

remote.h

@@ -25,6 +25,11 @@ struct remote {
 
 	const char *receivepack;
 	const char *uploadpack;
+
+	/*
+	 * for curl remotes only
+	 */
+	char *http_proxy;
 };
 
 struct remote *remote_get(const char *name);

transport.c

@@ -470,6 +470,10 @@ static struct ref *get_refs_via_curl(struct transport *transport)
 	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
 	curl_easy_setopt(slot->curl, CURLOPT_URL, refs_url);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
+	if (transport->remote->http_proxy)
+		curl_easy_setopt(slot->curl, CURLOPT_PROXY,
+				 transport->remote->http_proxy);
+
 	if (start_active_slot(slot)) {
 		run_active_slot(slot);
 		if (results.curl_result != CURLE_OK) {