Merge branch 'js/http-custom-headers'

HTTP transport clients learned to throw extra HTTP headers at the
server, specified via http.extraHeader configuration variable.

* js/http-custom-headers:
  http: support sending custom HTTP headers

Documentation/config.txt

@@ -1655,6 +1655,12 @@ http.emptyAuth::
 	a username in the URL, as libcurl normally requires a username for
 	authentication.
 
+http.extraHeader::
+	Pass an additional HTTP header when communicating with a server.  If
+	more than one such entry exists, all of them are added as extra
+	headers.  To allow overriding the settings inherited from the system
+	config, an empty value will reset the extra headers to the empty list.
+
 http.cookieFile::
 	File containing previously stored cookie lines which should be used
 	in the Git http session, if they match the server. The file format

http-push.c

@@ -211,7 +211,7 @@ static void curl_setup_http(CURL *curl, const char *url,
 static struct curl_slist *get_dav_token_headers(struct remote_lock *lock, enum dav_header_flag options)
 {
 	struct strbuf buf = STRBUF_INIT;
-	struct curl_slist *dav_headers = NULL;
+	struct curl_slist *dav_headers = http_copy_default_headers();
 
 	if (options & DAV_HEADER_IF) {
 		strbuf_addf(&buf, "If: (<%s>)", lock->token);
@@ -417,7 +417,7 @@ static void start_put(struct transfer_request *request)
 static void start_move(struct transfer_request *request)
 {
 	struct active_request_slot *slot;
-	struct curl_slist *dav_headers = NULL;
+	struct curl_slist *dav_headers = http_copy_default_headers();
 
 	slot = get_active_slot();
 	slot->callback_func = process_response;
@@ -845,7 +845,7 @@ static struct remote_lock *lock_remote(const char *path, long timeout)
 	char *ep;
 	char timeout_header[25];
 	struct remote_lock *lock = NULL;
-	struct curl_slist *dav_headers = NULL;
+	struct curl_slist *dav_headers = http_copy_default_headers();
 	struct xml_ctx ctx;
 	char *escaped;
 
@@ -1126,7 +1126,7 @@ static void remote_ls(const char *path, int flags,
 	struct slot_results results;
 	struct strbuf in_buffer = STRBUF_INIT;
 	struct buffer out_buffer = { STRBUF_INIT, 0 };
-	struct curl_slist *dav_headers = NULL;
+	struct curl_slist *dav_headers = http_copy_default_headers();
 	struct xml_ctx ctx;
 	struct remote_ls_ctx ls;
 
@@ -1204,7 +1204,7 @@ static int locking_available(void)
 	struct slot_results results;
 	struct strbuf in_buffer = STRBUF_INIT;
 	struct buffer out_buffer = { STRBUF_INIT, 0 };
-	struct curl_slist *dav_headers = NULL;
+	struct curl_slist *dav_headers = http_copy_default_headers();
 	struct xml_ctx ctx;
 	int lock_flags = 0;
 	char *escaped;

http.c

@@ -114,6 +114,7 @@ static unsigned long http_auth_methods = CURLAUTH_ANY;
 
 static struct curl_slist *pragma_header;
 static struct curl_slist *no_pragma_header;
+static struct curl_slist *extra_http_headers;
 
 static struct active_request_slot *active_queue_head;
 
@@ -323,6 +324,19 @@ static int http_options(const char *var, const char *value, void *cb)
 #endif
 	}
 
+	if (!strcmp("http.extraheader", var)) {
+		if (!value) {
+			return config_error_nonbool(var);
+		} else if (!*value) {
+			curl_slist_free_all(extra_http_headers);
+			extra_http_headers = NULL;
+		} else {
+			extra_http_headers =
+				curl_slist_append(extra_http_headers, value);
+		}
+		return 0;
+	}
+
 	/* Fall back on the default ones */
 	return git_default_config(var, value, cb);
 }
@@ -678,8 +692,10 @@ void http_init(struct remote *remote, const char *url, int proactive_auth)
 	if (remote)
 		var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);
 
-	pragma_header = curl_slist_append(pragma_header, "Pragma: no-cache");
-	no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
+	pragma_header = curl_slist_append(http_copy_default_headers(),
+		"Pragma: no-cache");
+	no_pragma_header = curl_slist_append(http_copy_default_headers(),
+		"Pragma:");
 
 #ifdef USE_CURL_MULTI
 	{
@@ -765,6 +781,9 @@ void http_cleanup(void)
 #endif
 	curl_global_cleanup();
 
+	curl_slist_free_all(extra_http_headers);
+	extra_http_headers = NULL;
+
 	curl_slist_free_all(pragma_header);
 	pragma_header = NULL;
 
@@ -1163,6 +1182,16 @@ int run_one_slot(struct active_request_slot *slot,
 	return handle_curl_result(results);
 }
 
+struct curl_slist *http_copy_default_headers(void)
+{
+	struct curl_slist *headers = NULL, *h;
+
+	for (h = extra_http_headers; h; h = h->next)
+		headers = curl_slist_append(headers, h->data);
+
+	return headers;
+}
+
 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
 {
 	char *ptr;
@@ -1380,7 +1409,7 @@ static int http_request(const char *url,
 {
 	struct active_request_slot *slot;
 	struct slot_results results;
-	struct curl_slist *headers = NULL;
+	struct curl_slist *headers = http_copy_default_headers();
 	struct strbuf buf = STRBUF_INIT;
 	const char *accept_language;
 	int ret;

http.h

@@ -106,6 +106,7 @@ extern void step_active_slots(void);
 extern void http_init(struct remote *remote, const char *url,
 		      int proactive_auth);
 extern void http_cleanup(void);
+extern struct curl_slist *http_copy_default_headers(void);
 
 extern long int git_curl_ipresolve;
 extern int active_requests;

remote-curl.c

@@ -474,7 +474,7 @@ static int run_slot(struct active_request_slot *slot,
 static int probe_rpc(struct rpc_state *rpc, struct slot_results *results)
 {
 	struct active_request_slot *slot;
-	struct curl_slist *headers = NULL;
+	struct curl_slist *headers = http_copy_default_headers();
 	struct strbuf buf = STRBUF_INIT;
 	int err;
 
@@ -503,7 +503,7 @@ static int probe_rpc(struct rpc_state *rpc, struct slot_results *results)
 static int post_rpc(struct rpc_state *rpc)
 {
 	struct active_request_slot *slot;
-	struct curl_slist *headers = NULL;
+	struct curl_slist *headers = http_copy_default_headers();
 	int use_gzip = rpc->gzip_request;
 	char *gzip_body = NULL;
 	size_t gzip_size = 0;

t/lib-httpd/apache.conf

@@ -102,6 +102,14 @@ Alias /auth/dumb/ www/auth/dumb/
 	SetEnv GIT_HTTP_EXPORT_ALL
 	Header set Set-Cookie name=value
 </LocationMatch>
+<LocationMatch /smart_headers/>
+	<RequireAll>
+		Require expr %{HTTP:x-magic-one} == 'abra'
+		Require expr %{HTTP:x-magic-two} == 'cadabra'
+	</RequireAll>
+	SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
+	SetEnv GIT_HTTP_EXPORT_ALL
+</LocationMatch>
 ScriptAliasMatch /smart_*[^/]*/(.*) ${GIT_EXEC_PATH}/git-http-backend/$1
 ScriptAlias /broken_smart/ broken-smart-http.sh/
 ScriptAlias /error/ error.sh/

t/t5551-http-fetch-smart.sh

@@ -282,5 +282,12 @@ test_expect_success EXPENSIVE 'http can handle enormous ref negotiation' '
 	test_line_count = 100000 tags
 '
 
+test_expect_success 'custom http headers' '
+	test_must_fail git fetch "$HTTPD_URL/smart_headers/repo.git" &&
+	git -c http.extraheader="x-magic-one: abra" \
+	    -c http.extraheader="x-magic-two: cadabra" \
+	    fetch "$HTTPD_URL/smart_headers/repo.git"
+'
+
 stop_httpd
 test_done