Fix rel_date leak on DateInterval construction failure

Author: nikic

ext/date/php_date.c

@@ -3838,6 +3838,9 @@ static int date_interval_initialize(timelib_rel_time **rt, /*const*/ char *forma
 	if (errors->error_count > 0) {
 		php_error_docref(NULL, E_WARNING, "Unknown or bad format (%s)", format);
 		retval = FAILURE;
+		if (p) {
+			timelib_rel_time_dtor(p);
+		}
 	} else {
 		if(p) {
 			*rt = p;

ext/date/tests/date_interval_bad_format_leak.phpt

@@ -0,0 +1,14 @@
+--TEST--
+DateInterval with bad format should not leak period
+--FILE--
+<?php
+
+try {
+    $interval = new DateInterval('P3"D');
+} catch (Exception $e) {
+    echo $e->getMessage(), "\n";
+}
+
+?>
+--EXPECT--
+DateInterval::__construct(): Unknown or bad format (P3"D)