http: try http_proxy env var when http.proxy config option is not set

cURL already reads it, but if $http_proxy has username but no password
cURL will not ask you for the password and so failed to authenticate
returning a 407 error code. So we read it ourselves to detect that and
ask for the password. Also we read it prior to connection to be able to
make a proactive authentication in case the flag http_proactive_auth is
set.

We also take care to read env proxy var according to protocol being
used in the destination url, e.g.  when the url to retrieve is a https
one, then the proxy env var we look at is https_proxy. To make this
possible we now passed destination url parameter to get_active_slot()
and get_curl_handle() functions.

We also read no_proxy env var so to ignore aforementioned proxy env var
if no_proxy contains an asterisk ('*') or contains the host used in url
destination.

Signed-off-by: Nelson Benitez Leon <nbenitezl@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

http-push.c

@@ -297,7 +297,7 @@ static void start_mkcol(struct transfer_request *request)
 
 	request->url = get_remote_object_url(repo->url, hex, 1);
 
-	slot = get_active_slot();
+	slot = get_active_slot(request->url);
 	slot->callback_func = process_response;
 	slot->callback_data = request;
 	curl_setup_http_get(slot->curl, request->url, DAV_MKCOL);
@@ -417,7 +417,7 @@ static void start_put(struct transfer_request *request)
 	strbuf_add(&buf, request->lock->tmpfile_suffix, 41);
 	request->url = strbuf_detach(&buf, NULL);
 
-	slot = get_active_slot();
+	slot = get_active_slot(request->url);
 	slot->callback_func = process_response;
 	slot->callback_data = request;
 	curl_setup_http(slot->curl, request->url, DAV_PUT,
@@ -438,7 +438,7 @@ static void start_move(struct transfer_request *request)
 	struct active_request_slot *slot;
 	struct curl_slist *dav_headers = NULL;
 
-	slot = get_active_slot();
+	slot = get_active_slot(request->url);
 	slot->callback_func = process_response;
 	slot->callback_data = request;
 	curl_setup_http_get(slot->curl, request->url, DAV_MOVE);
@@ -467,7 +467,7 @@ static int refresh_lock(struct remote_lock *lock)
 
 	dav_headers = get_dav_token_headers(lock, DAV_HEADER_IF | DAV_HEADER_TIMEOUT);
 
-	slot = get_active_slot();
+	slot = get_active_slot(lock->url);
 	slot->results = &results;
 	curl_setup_http_get(slot->curl, lock->url, DAV_LOCK);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
@@ -882,7 +882,7 @@ static struct remote_lock *lock_remote(const char *path, long timeout)
 	while (ep) {
 		char saved_character = ep[1];
 		ep[1] = '\0';
-		slot = get_active_slot();
+		slot = get_active_slot(url);
 		slot->results = &results;
 		curl_setup_http_get(slot->curl, url, DAV_MKCOL);
 		if (start_active_slot(slot)) {
@@ -912,7 +912,7 @@ static struct remote_lock *lock_remote(const char *path, long timeout)
 	dav_headers = curl_slist_append(dav_headers, timeout_header);
 	dav_headers = curl_slist_append(dav_headers, "Content-Type: text/xml");
 
-	slot = get_active_slot();
+	slot = get_active_slot(url);
 	slot->results = &results;
 	curl_setup_http(slot->curl, url, DAV_LOCK, &out_buffer, fwrite_buffer);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
@@ -980,7 +980,7 @@ static int unlock_remote(struct remote_lock *lock)
 
 	dav_headers = get_dav_token_headers(lock, DAV_HEADER_LOCK);
 
-	slot = get_active_slot();
+	slot = get_active_slot(lock->url);
 	slot->results = &results;
 	curl_setup_http_get(slot->curl, lock->url, DAV_UNLOCK);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, dav_headers);
@@ -1158,7 +1158,7 @@ static void remote_ls(const char *path, int flags,
 	dav_headers = curl_slist_append(dav_headers, "Depth: 1");
 	dav_headers = curl_slist_append(dav_headers, "Content-Type: text/xml");
 
-	slot = get_active_slot();
+	slot = get_active_slot(url);
 	slot->results = &results;
 	curl_setup_http(slot->curl, url, DAV_PROPFIND,
 			&out_buffer, fwrite_buffer);
@@ -1232,7 +1232,7 @@ static int locking_available(void)
 	dav_headers = curl_slist_append(dav_headers, "Depth: 0");
 	dav_headers = curl_slist_append(dav_headers, "Content-Type: text/xml");
 
-	slot = get_active_slot();
+	slot = get_active_slot(repo->url);
 	slot->results = &results;
 	curl_setup_http(slot->curl, repo->url, DAV_PROPFIND,
 			&out_buffer, fwrite_buffer);
@@ -1409,7 +1409,7 @@ static int update_remote(unsigned char *sha1, struct remote_lock *lock)
 
 	strbuf_addf(&out_buffer.buf, "%s\n", sha1_to_hex(sha1));
 
-	slot = get_active_slot();
+	slot = get_active_slot(lock->url);
 	slot->results = &results;
 	curl_setup_http(slot->curl, lock->url, DAV_PUT,
 			&out_buffer, fwrite_null);
@@ -1535,7 +1535,7 @@ static void update_remote_info_refs(struct remote_lock *lock)
 	if (!aborted) {
 		dav_headers = get_dav_token_headers(lock, DAV_HEADER_IF);
 
-		slot = get_active_slot();
+		slot = get_active_slot(lock->url);
 		slot->results = &results;
 		curl_setup_http(slot->curl, lock->url, DAV_PUT,
 				&buffer, fwrite_null);
@@ -1695,7 +1695,7 @@ static int delete_remote_branch(const char *pattern, int force)
 		return 0;
 	url = xmalloc(strlen(repo->url) + strlen(remote_ref->name) + 1);
 	sprintf(url, "%s%s", repo->url, remote_ref->name);
-	slot = get_active_slot();
+	slot = get_active_slot(url);
 	slot->results = &results;
 	curl_setup_http_get(slot->curl, url, DAV_DELETE);
 	if (start_active_slot(slot)) {

http-walker.c

@@ -348,7 +348,7 @@ static void fetch_alternates(struct walker *walker, const char *base)
 	 * Use a callback to process the result, since another request
 	 * may fail and need to have alternates loaded before continuing
 	 */
-	slot = get_active_slot();
+	slot = get_active_slot(url);
 	slot->callback_func = process_alternates_response;
 	alt_req.walker = walker;
 	slot->callback_data = &alt_req;

http.c

@@ -42,6 +42,7 @@ static long curl_low_speed_time = -1;
 static int curl_ftp_no_epsv;
 static const char *curl_http_proxy;
 static const char *curl_cookie_file;
+static struct credential cre_url = CREDENTIAL_INIT;
 static struct credential http_auth = CREDENTIAL_INIT;
 static int http_proactive_auth;
 static const char *user_agent;
@@ -232,7 +233,7 @@ static int has_cert_password(void)
 	return 1;
 }
 
-static CURL *get_curl_handle(void)
+static CURL *get_curl_handle(const char *url)
 {
 	CURL *result = curl_easy_init();
 
@@ -295,6 +296,28 @@ static CURL *get_curl_handle(void)
 	if (curl_ftp_no_epsv)
 		curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 
+	if (!curl_http_proxy) {
+		const char *env_proxy, *no_proxy;
+		char *env_proxy_var;
+		int read_http_proxy;
+		struct strbuf buf = STRBUF_INIT;
+		credential_from_url(&cre_url, url);
+		strbuf_addf(&buf, "%s_proxy", cre_url.protocol);
+		env_proxy_var = strbuf_detach(&buf, NULL);
+		env_proxy = getenv(env_proxy_var);
+		if (env_proxy) {
+			read_http_proxy = 1;
+			no_proxy = getenv("no_proxy");
+			if (!no_proxy)
+				no_proxy = getenv("NO_PROXY");
+			if (no_proxy && (!strcmp("*", no_proxy) || strstr(no_proxy, cre_url.host)))
+				read_http_proxy = 0;
+
+			if (read_http_proxy)
+				curl_http_proxy = xstrdup(env_proxy);
+		}
+		free(env_proxy_var);
+	}
 	if (curl_http_proxy) {
 		curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 		curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
@@ -385,7 +408,7 @@ void http_init(struct remote *remote, const char *url, int proactive_auth)
 	}
 
 #ifndef NO_CURL_EASY_DUPHANDLE
-	curl_default = get_curl_handle();
+	curl_default = get_curl_handle(url);
 #endif
 }
 
@@ -434,7 +457,7 @@ void http_cleanup(void)
 	ssl_cert_password_required = 0;
 }
 
-struct active_request_slot *get_active_slot(void)
+struct active_request_slot *get_active_slot(const char *url)
 {
 	struct active_request_slot *slot = active_queue_head;
 	struct active_request_slot *newslot;
@@ -472,7 +495,7 @@ struct active_request_slot *get_active_slot(void)
 
 	if (slot->curl == NULL) {
 #ifdef NO_CURL_EASY_DUPHANDLE
-		slot->curl = get_curl_handle();
+		slot->curl = get_curl_handle(url);
 #else
 		slot->curl = curl_easy_duphandle(curl_default);
 #endif
@@ -745,7 +768,7 @@ static int http_request(const char *url, void *result, int target, int options)
 	struct strbuf buf = STRBUF_INIT;
 	int ret;
 
-	slot = get_active_slot();
+	slot = get_active_slot(url);
 	slot->results = &results;
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 
@@ -1090,7 +1113,7 @@ struct http_pack_request *new_http_pack_request(
 		goto abort;
 	}
 
-	preq->slot = get_active_slot();
+	preq->slot = get_active_slot(preq->url);
 	curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
 	curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
 	curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
@@ -1250,7 +1273,7 @@ struct http_object_request *new_http_object_request(const char *base_url,
 		}
 	}
 
-	freq->slot = get_active_slot();
+	freq->slot = get_active_slot(freq->url);
 
 	curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
 	curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);

http.h

@@ -73,7 +73,7 @@ extern curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp);
 #endif
 
 /* Slot lifecycle functions */
-extern struct active_request_slot *get_active_slot(void);
+extern struct active_request_slot *get_active_slot(const char *url);
 extern int start_active_slot(struct active_request_slot *slot);
 extern void run_active_slot(struct active_request_slot *slot);
 extern void finish_active_slot(struct active_request_slot *slot);

remote-curl.c

@@ -383,7 +383,7 @@ static int probe_rpc(struct rpc_state *rpc)
 	struct strbuf buf = STRBUF_INIT;
 	int err;
 
-	slot = get_active_slot();
+	slot = get_active_slot(rpc->service_url);
 
 	headers = curl_slist_append(headers, rpc->hdr_content_type);
 	headers = curl_slist_append(headers, rpc->hdr_accept);
@@ -440,7 +440,7 @@ static int post_rpc(struct rpc_state *rpc)
 			return err;
 	}
 
-	slot = get_active_slot();
+	slot = get_active_slot(rpc->service_url);
 
 	curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
 	curl_easy_setopt(slot->curl, CURLOPT_POST, 1);