http: do not ignore proxy path

The documentation for `http.proxy` describes that option, and the
environment variables it overrides, as supporting "the syntax understood
by curl". curl allows SOCKS proxies to use a path to a Unix domain
socket, like `socks5h://localhost/path/to/socket.sock`. Git should
therefore include, if present, the path part of the proxy URL in what it
passes to libcurl.

Co-authored-by: Jeff King <peff@peff.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Ryan Hendrickson <ryan.hendrickson@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 23 insertions, 1 deletions

diff --git a/http.c b/http.c
index 623ed23489..6c6cc5c822 100644
--- a/http.c
+++ b/http.c
@@ -1227,6 +1227,8 @@ static CURL *get_curl_handle(void)
 		 */
 		curl_easy_setopt(result, CURLOPT_PROXY, "");
 	} else if (curl_http_proxy) {
+		struct strbuf proxy = STRBUF_INIT;
+
 		if (starts_with(curl_http_proxy, "socks5h"))
 			curl_easy_setopt(result,
 				CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5_HOSTNAME);
@@ -1265,7 +1267,27 @@ static CURL *get_curl_handle(void)
 		if (!proxy_auth.host)
 			die("Invalid proxy URL '%s'", curl_http_proxy);
 
-		curl_easy_setopt(result, CURLOPT_PROXY, proxy_auth.host);
+		strbuf_addstr(&proxy, proxy_auth.host);
+		if (proxy_auth.path) {
+			curl_version_info_data *ver = curl_version_info(CURLVERSION_NOW);
+
+			if (ver->version_num < 0x075400)
+				die("libcurl 7.84 or later is required to support paths in proxy URLs");
+
+			if (!starts_with(proxy_auth.protocol, "socks"))
+				die("Invalid proxy URL '%s': only SOCKS proxies support paths",
+				    curl_http_proxy);
+
+			if (strcasecmp(proxy_auth.host, "localhost"))
+				die("Invalid proxy URL '%s': host must be localhost if a path is present",
+				    curl_http_proxy);
+
+			strbuf_addch(&proxy, '/');
+			strbuf_add_percentencode(&proxy, proxy_auth.path, 0);
+		}
+		curl_easy_setopt(result, CURLOPT_PROXY, proxy.buf);
+		strbuf_release(&proxy);
+
 		var_override(&curl_no_proxy, getenv("NO_PROXY"));
 		var_override(&curl_no_proxy, getenv("no_proxy"));
 		curl_easy_setopt(result, CURLOPT_NOPROXY, curl_no_proxy);