Fix mbregex search state after cache invalidation

Author: matthiasgoergens

ext/mbstring/php_mbregex.c

@@ -481,6 +481,10 @@ static php_mb_regex_t *php_mbregex_compile_pattern(const char *pattern, size_t p
 		if (rc == MBREX(search_re)) {
 			/* reuse the new rc? see bug #72399 */
 			MBREX(search_re) = NULL;
+			if (MBREX(search_regs) != NULL) {
+				onig_region_free(MBREX(search_regs), 1);
+				MBREX(search_regs) = NULL;
+			}
 		}
 		zend_hash_str_update_ptr(&MBREX(ht_rc), (char *)pattern, patlen, retval);
 	} else {

ext/mbstring/tests/gh21036.phpt

@@ -0,0 +1,17 @@
+--TEST--
+GH-21036 (mb_ereg_search_getregs() after regex cache invalidation)
+--EXTENSIONS--
+mbstring
+--FILE--
+<?php
+error_reporting(E_ALL & ~E_DEPRECATED);
+
+$pattern = '(?<name>a)';
+mb_ereg_search_init('a', $pattern);
+mb_ereg_search_pos();
+mb_eregi($pattern, 'a');
+
+var_dump(mb_ereg_search_getregs());
+?>
+--EXPECT--
+bool(false)