Promote warnings to errors in str_repeat()

ext/mbstring/tests/bug73646.phpt

@@ -7,10 +7,7 @@ if (!function_exists('mb_ereg')) die('skip mbregex support not available');
 ?>
 --FILE--
 <?php
-
-$v1=str_repeat("#", -1);
-var_dump(mb_ereg_search_init($v1));
+var_dump(mb_ereg_search_init(NULL));
 ?>
---EXPECTF--
-Warning: str_repeat(): Second argument has to be greater than or equal to 0 in %sbug73646.php on line %d
+--EXPECT--
 bool(true)

ext/opcache/tests/bug70207.phpt

@@ -14,7 +14,9 @@ function bar() {
 }
 function foo() {
     try { return bar(); }
-    finally { @str_repeat("foo", -10); }
+    finally {
+        @fopen("non-existent", 'r');
+    }
 }
 
 var_dump(foo());

ext/standard/string.c

@@ -5363,7 +5363,7 @@ PHP_FUNCTION(str_repeat)
 	ZEND_PARSE_PARAMETERS_END();
 
 	if (mult < 0) {
-		php_error_docref(NULL, E_WARNING, "Second argument has to be greater than or equal to 0");
+		zend_throw_error(NULL, "Second argument has to be greater than or equal to 0");
 		return;
 	}
 

ext/standard/tests/strings/str_repeat_variation1.phpt

@@ -0,0 +1,22 @@
+--TEST--
+Test str_repeat() function: usage variations - complex strings containing other than 7-bit chars
+--INI--
+precision=14
+--FILE--
+<?php
+$str = chr(0).chr(128).chr(129).chr(234).chr(235).chr(254).chr(255);
+
+$withCodePoint = str_repeat($str, chr(51)); // ASCII value of '3' given
+$explicit = str_repeat($str, 3);
+
+var_dump($withCodePoint === $explicit);
+var_dump( bin2hex( $withCodePoint ) );
+var_dump( bin2hex( $explicit ) );
+
+?>
+DONE
+--EXPECT--
+bool(true)
+string(42) "008081eaebfeff008081eaebfeff008081eaebfeff"
+string(42) "008081eaebfeff008081eaebfeff008081eaebfeff"
+DONE