soap: do not overwrite the parsed host on a protocol-relative redirect

When a redirect Location is a protocol-relative reference (//host/path),
php_url_parse() already fills new_url->host, but the scheme-less redirect
handling overwrote it with a copy of the request host without releasing
the parsed one. That leaks a zend_string per such redirect and pins the
redirect back to the original host instead of the one the server named.
Inherit host and port from the request URL only when new_url->host is
NULL, mirroring the scheme guard directly above.

Author: iliaal

ext/soap/php_http.c

@@ -1151,8 +1151,10 @@ int make_http_soap_request(zval        *this_ptr,
 				zend_string_release_ex(http_body, 0);
 				if (new_url->scheme == NULL && new_url->path != NULL) {
 					new_url->scheme = phpurl->scheme ? zend_string_copy(phpurl->scheme) : NULL;
-					new_url->host = phpurl->host ? zend_string_copy(phpurl->host) : NULL;
-					new_url->port = phpurl->port;
+					if (new_url->host == NULL) {
+						new_url->host = phpurl->host ? zend_string_copy(phpurl->host) : NULL;
+						new_url->port = phpurl->port;
+					}
 					if (new_url->path && ZSTR_VAL(new_url->path)[0] != '/') {
 						if (phpurl->path) {
 							char *t = ZSTR_VAL(phpurl->path);

ext/soap/tests/bugs/protocol_relative_redirect.phpt

@@ -0,0 +1,49 @@
+--TEST--
+SOAP client follows a protocol-relative (//host/path) redirect Location without leaking the host
+--EXTENSIONS--
+soap
+--SKIPIF--
+<?php
+if (!file_exists(__DIR__ . "/../../../../sapi/cli/tests/php_cli_server.inc")) {
+    echo "skip sapi/cli/tests/php_cli_server.inc required but not found";
+}
+?>
+--FILE--
+<?php
+include __DIR__ . "/../../../../sapi/cli/tests/php_cli_server.inc";
+
+$args = ["-d", "extension_dir=" . ini_get("extension_dir"), "-d", "extension=" . (substr(PHP_OS, 0, 3) == "WIN" ? "php_" : "") . "soap." . PHP_SHLIB_SUFFIX];
+if (php_ini_loaded_file()) {
+    $args[] = "-c";
+    $args[] = php_ini_loaded_file();
+}
+
+$code = <<<'PHP'
+if ($_SERVER["REQUEST_URI"] === "/redirected") {
+    header("Content-Type: text/xml; charset=utf-8");
+    echo '<?xml version="1.0" encoding="UTF-8"?>',
+        '<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">',
+        '<SOAP-ENV:Body><fooResponse><result>ok</result></fooResponse></SOAP-ENV:Body>',
+        '</SOAP-ENV:Envelope>';
+} else {
+    http_response_code(302);
+    header("Location: //" . $_SERVER["HTTP_HOST"] . "/redirected");
+}
+PHP;
+
+php_cli_server_start($code, null, $args);
+
+$client = new SoapClient(null, [
+    'location' => 'http://' . PHP_CLI_SERVER_ADDRESS . '/start',
+    'uri' => 'test-uri',
+]);
+
+try {
+    $client->__soapCall("foo", []);
+    echo "redirect followed\n";
+} catch (SoapFault $e) {
+    echo "SoapFault: " . $e->getMessage() . "\n";
+}
+?>
+--EXPECT--
+redirect followed