Merge branch 'PHP-7.1'

ext/standard/string.c

@@ -5276,10 +5276,10 @@ PHP_FUNCTION(substr_count)
 
 	if (ac == 4) {
 
-		if (length <= 0) {
+		if (length < 0) {
 			length += (haystack_len - offset);
 		}
-		if ((length <= 0) || ((size_t)length > (haystack_len - offset))) {
+		if (length < 0 || ((size_t)length > (haystack_len - offset))) {
 			php_error_docref(NULL, E_WARNING, "Invalid length value");
 			RETURN_FALSE;
 		}

ext/standard/tests/strings/bug74041.phpt

@@ -0,0 +1,12 @@
+--TEST--
+Bug #74041: substr_count with length=0 broken
+--FILE--
+<?php
+
+var_dump(substr_count("aaa", "a", 0, 0));
+var_dump(substr_count("", "a", 0, 0));
+
+?>
+--EXPECT--
+int(0)
+int(0)