vweb: split and parse Content-Type header correctly (#9756)

vlib/vweb/request.v

@@ -147,6 +147,7 @@ fn lines_to_string(len int, lines []string, start int, end int) string {
 	for i in start .. end {
 		sb.writeln(lines[i])
 	}
+	sb.cut_last(1) // last newline
 	res := sb.str()
 	unsafe { sb.free() }
 	return res

vlib/vweb/request_test.v

@@ -112,17 +112,16 @@ ${contents[1]}
 --------------------------$boundary--
 '
 	form, files := parse_multipart_form(data, boundary)
-	// TODO: remove newlines
 	assert files == map{
 		names[0]: [FileData{
 			filename: file
 			content_type: ct
-			data: contents[0] + '\n'
+			data: contents[0]
 		}]
 	}
 
 	assert form == map{
-		names[1]: contents[1] + '\n'
+		names[1]: contents[1]
 	}
 }
 

vlib/vweb/tests/vweb_test.v

@@ -208,6 +208,31 @@ fn test_http_client_json_post() ? {
 	assert '$ouser' == '$nuser2'
 }
 
+fn test_http_client_multipart_form_data() ? {
+	boundary := '6844a625b1f0b299'
+	name := 'foo'
+	ct := 'multipart/form-data; boundary=------------------------$boundary'
+	contents := 'baz buzz'
+	data := '--------------------------$boundary
+Content-Disposition: form-data; name=\"$name\"
+
+$contents
+--------------------------$boundary--
+'
+	mut x := http.fetch('http://127.0.0.1:$sport/form_echo',
+		method: .post
+		header: http.new_header(
+			key: .content_type
+			value: ct
+		)
+		data: data
+	) ?
+	$if debug_net_socket_client ? {
+		eprintln('/form_echo endpoint response: $x')
+	}
+	assert x.text == contents
+}
+
 fn test_http_client_shutdown_does_not_work_without_a_cookie() {
 	x := http.get('http://127.0.0.1:$sport/shutdown') or {
 		assert err.msg == ''

vlib/vweb/tests/vweb_test_server.v

@@ -85,6 +85,12 @@ pub fn (mut app App) json_echo() vweb.Result {
 	return app.ok(app.req.data)
 }
 
+['/form_echo'; post]
+pub fn (mut app App) form_echo() vweb.Result {
+	app.set_content_type(app.req.header.get(.content_type) or { '' })
+	return app.ok(app.form['foo'])
+}
+
 // Make sure [post] works without the path
 [post]
 pub fn (mut app App) json() vweb.Result {

vlib/vweb/vweb.v

@@ -336,8 +336,9 @@ fn handle_conn<T>(mut conn net.TcpConn, mut app T) {
 		page_gen_start: page_gen_start
 	}
 	if req.method in vweb.methods_with_form {
-		if 'multipart/form-data' in req.header.values(.content_type) {
+		ct := req.header.get(.content_type) or { '' }.split(';').map(it.trim_left(' \t'))
-			boundary := req.header.values(.content_type).filter(it.starts_with('boundary='))
+		if 'multipart/form-data' in ct {
+			boundary := ct.filter(it.starts_with('boundary='))
 			if boundary.len != 1 {
 				send_string(mut conn, vweb.http_400) or {}
 				return