MDL-40877 core_text: Added UTF-8 safe strrchr method

lib/tests/textlib_test.php

@@ -379,6 +379,17 @@ class core_textlib_testcase extends advanced_testcase {
         $this->assertSame($textlib->specialtoascii('ábc'), 'abc');
         $this->assertSame($textlib->strtotitle('abc ABC'), 'Abc Abc');
     }
+
+    /**
+     * Test strrchr.
+     */
+    public function test_strrchr() {
+        $str = "Žluťoučký koníček";
+        $this->assertSame('koníček', textlib::strrchr($str, 'koní'));
+        $this->assertSame('Žluťoučký ', textlib::strrchr($str, 'koní', true));
+        $this->assertFalse(textlib::strrchr($str, 'A'));
+        $this->assertFalse(textlib::strrchr($str, 'ç', true));
+    }
 }
 
 

lib/textlib.class.php

@@ -238,6 +238,36 @@ class textlib {
         return $result;
     }
 
+    /**
+     * Finds the last occurrence of a character in a string within another.
+     * UTF-8 ONLY safe mb_strrchr().
+     *
+     * @param string $haystack The string from which to get the last occurrence of needle.
+     * @param string $needle The string to find in haystack.
+     * @param boolean $part If true, returns the portion before needle, else return the portion after (including needle).
+     * @return string|false False when not found.
+     * @since 2.4.6, 2.5.2, 2.6
+     */
+    public static function strrchr($haystack, $needle, $part = false) {
+
+        if (function_exists('mb_strrchr')) {
+            return mb_strrchr($haystack, $needle, $part, 'UTF-8');
+        }
+
+        $pos = self::strrpos($haystack, $needle);
+        if ($pos === false) {
+            return false;
+        }
+
+        $length = null;
+        if ($part) {
+            $length = $pos;
+            $pos = 0;
+        }
+
+        return self::substr($haystack, $pos, $length, 'utf-8');
+    }
+
     /**
      * Multibyte safe strlen() function, uses mbstring or iconv for UTF-8, falls back to typo3.
      *