add support for negative offset in strpos and stripos (#1441)

* fix tests..

* fix tests...

* del unused include

Author: denisichh

runtime-common/stdlib/string/string-functions.cpp

@@ -1241,12 +1241,12 @@ string f$stripslashes(const string& str) noexcept {
 
 Optional<int64_t> f$stripos(const string& haystack, const string& needle, int64_t offset) noexcept {
   if (offset < 0) {
-    php_warning("Wrong offset = %" PRIi64 " in function stripos", offset);
-    return false;
+    offset += haystack.size();
   }
-  if (offset >= haystack.size()) {
+  if (offset < 0 || offset >= haystack.size()) {
     return false;
   }
+
   if (needle.size() == 0) {
     php_warning("Parameter needle is empty in function stripos");
     return false;
@@ -1726,12 +1726,12 @@ int64_t f$strnatcmp(const string& lhs, const string& rhs) noexcept {
 
 Optional<int64_t> f$strpos(const string& haystack, const string& needle, int64_t offset) noexcept {
   if (offset < 0) {
-    php_warning("Wrong offset = %" PRIi64 " in function strpos", offset);
-    return false;
+    offset += haystack.size();
   }
-  if (offset > int64_t{haystack.size()}) {
+  if (offset < 0 || offset >= haystack.size()) {
     return false;
   }
+
   if (needle.size() <= 1) {
     if (needle.size() == 0) {
       php_warning("Parameter needle is empty in function strpos");

tests/phpt/dl/491_strpos.php

@@ -52,6 +52,27 @@
   var_dump (mb_strtoupper($str, 'UTF-8'));
   // var_dump(strtolower ("ÈÔÛÛÀÏÂÀ¨"));
 
+  var_dump(strpos("abcdABCDefghEFGHefgh", "efgh", -10));
+  var_dump(strpos("abcdABCDefghEFGHefgh", "efgh", -16));
+  var_dump(strpos("abcdABCDefghEFGh_H", "h", -10));
+  var_dump(strpos("abcdABCDefghEFGh_H", "h", -5));
+  var_dump(strpos("abcdABCDefghEFGh_H", "h", -2));
+  var_dump(strpos("0123456789a123456789b123456789c", "7", -5));
+  var_dump(strpos("0123456789a123456789b123456789c", "7", -25));
+  var_dump(strpos("0123456789a123456789b123456789c", "c", -1));
+  var_dump(strpos("0123456789a123456789b123456789c", "9", -1));
+
+  var_dump(stripos("abcdABCDefghEFGHefgh", "efgh", -10));
+  var_dump(stripos("abcdABCDefghEFGHefgh", "efgh", -16));
+  var_dump(stripos("abcdABCDefghEFGh_H", "h", -10));
+  var_dump(stripos("abcdABCDefghEFGh_H", "h", -5));
+  var_dump(stripos("abcdABCDefghEFGh_H", "h", -2));
+  var_dump(stripos("0123456789a123456789b123456789c", "7", -5));
+  var_dump(stripos("0123456789a123456789b123456789c", "7", -25));
+  var_dump(stripos("0123456789a123456789b123456789c", "c", -1));
+  var_dump(stripos("0123456789a123456789b123456789c", "9", -1));
+
+
   $a = array ("                                             ", "The quick brown fox jumped over the lazy dog.", "A very long woooooooooooord.", "A very long wooooooooooooord.", "A very long woooooooooooord.", "", "A   very  long    wooooooooooooord.", "A   very  long    wooooooooooooord        234234234 e r we we r we rwe f  w     ew r wer we                  wer wer we r wer .");
   foreach ($a as $str) {
     var_dump (nl2br (wordwrap ($str, 1, "\n", true)));