From d276e6a8386a68d57d5dd07c3d7e15de4b03c6b3 Mon Sep 17 00:00:00 2001
From: "Christoph M. Becker" <cmb@php.net>
Date: Thu, 28 Jul 2016 13:07:05 +0200
Subject: [PATCH] Fix #72691: mb_ereg_search raises a warning if a match
 zero-width

That warning doesn't make sense (PCRE doesn't throw such a warning either),
so we remove it.
---
 NEWS                             |  5 ++++
 ext/mbstring/php_mbregex.c       |  3 --
 ext/mbstring/tests/bug72691.phpt | 48 ++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+), 3 deletions(-)
 create mode 100644 ext/mbstring/tests/bug72691.phpt

diff --git a/NEWS b/NEWS
index 3ab22a87aba..962be025812 100644
--- a/NEWS
+++ b/NEWS
@@ -40,6 +40,11 @@ PHP                                                                        NEWS
 - Intl:
   . Partially fixed #72506 (idn_to_ascii for UTS #46 incorrect for long domain
     names). (cmb)
+
+- mbstring:
+  . Fixed bug #72691 (mb_ereg_search raises a warning if a match zero-width).
+    (cmb)
+
 - PCRE:
   . Fixed bug #72688 (preg_match missing group names in matches). (cmb)
 
diff --git a/ext/mbstring/php_mbregex.c b/ext/mbstring/php_mbregex.c
index 67951a828e3..3509165ca9e 100644
--- a/ext/mbstring/php_mbregex.c
+++ b/ext/mbstring/php_mbregex.c
@@ -1235,9 +1235,6 @@ _php_mb_regex_ereg_search_exec(INTERNAL_FUNCTION_PARAMETERS, int mode)
 		php_error_docref(NULL TSRMLS_CC, E_WARNING, "mbregex search failure in mbregex_search(): %s", err_str);
 		RETVAL_FALSE;
 	} else {
-		if (MBREX(search_regs)->beg[0] == MBREX(search_regs)->end[0]) {
-			php_error_docref(NULL TSRMLS_CC, E_WARNING, "Empty regular expression");
-		}
 		switch (mode) {
 		case 1:
 			array_init(return_value);
diff --git a/ext/mbstring/tests/bug72691.phpt b/ext/mbstring/tests/bug72691.phpt
new file mode 100644
index 00000000000..d914a508e05
--- /dev/null
+++ b/ext/mbstring/tests/bug72691.phpt
@@ -0,0 +1,48 @@
+--TEST--
+Bug #72691 (mb_ereg_search raises a warning if a match zero-width)
+--SKIPIF--
+<?php
+if (!extension_loaded('mbstring')) die('skip ext/mbstring required');
+?>
+--FILE--
+<?php
+$str = 'foo';
+mb_ereg_search_init($str);
+
+mb_ereg_search('\A');
+var_dump(mb_ereg_search_getpos());
+var_dump(mb_ereg_search_getregs());
+
+mb_ereg_search('\s*');
+var_dump(mb_ereg_search_getpos());
+var_dump(mb_ereg_search_getregs());
+
+mb_ereg_search('\w+');
+var_dump(mb_ereg_search_getpos());
+var_dump(mb_ereg_search_getregs());
+
+mb_ereg_search('\Z');
+var_dump(mb_ereg_search_getpos());
+var_dump(mb_ereg_search_getregs());
+?>
+--EXPECT--
+int(1)
+array(1) {
+  [0]=>
+  string(0) ""
+}
+int(2)
+array(1) {
+  [0]=>
+  string(0) ""
+}
+int(3)
+array(1) {
+  [0]=>
+  string(1) "o"
+}
+int(4)
+array(1) {
+  [0]=>
+  string(0) ""
+}