Copy UTF-8 flag for str_repeat

Author: nielsdos

Zend/zend_string.h

@@ -82,9 +82,13 @@ END_EXTERN_C()
 #define ZSTR_IS_INTERNED(s)					(GC_FLAGS(s) & IS_STR_INTERNED)
 #define ZSTR_IS_VALID_UTF8(s)				(GC_FLAGS(s) & IS_STR_VALID_UTF8)
 
+/* These are properties, encoded as flags, that will hold on the resulting string
+ * after concatenating two strings that have these property.
+ * Example: concatenating two UTF-8 strings yields another UTF-8 string. */
 #define ZSTR_COPYABLE_CONCAT_PROPERTIES		(IS_STR_VALID_UTF8)
 
 #define ZSTR_GET_COPYABLE_CONCAT_PROPERTIES(s) 				(GC_FLAGS(s) & ZSTR_COPYABLE_CONCAT_PROPERTIES)
+/* This macro returns the copyable concat properties which hold on both strings. */
 #define ZSTR_GET_COPYABLE_CONCAT_PROPERTIES_BOTH(s1, s2)	(GC_FLAGS(s1) & GC_FLAGS(s2) & ZSTR_COPYABLE_CONCAT_PROPERTIES)
 
 #define ZSTR_COPY_CONCAT_PROPERTIES(out, in) do { \

ext/standard/string.c

@@ -5059,6 +5059,7 @@ PHP_FUNCTION(str_repeat)
 	/* Initialize the result string */
 	result = zend_string_safe_alloc(ZSTR_LEN(input_str), mult, 0, 0);
 	result_len = ZSTR_LEN(input_str) * mult;
+	ZSTR_COPY_CONCAT_PROPERTIES(result, input_str);
 
 	/* Heavy optimization for situations where input string is 1 byte long */
 	if (ZSTR_LEN(input_str) == 1) {

ext/zend_test/tests/strings_marked_as_utf8.phpt

@@ -107,6 +107,14 @@ $s = $o . $o;
 var_dump($s);
 var_dump(zend_test_is_string_marked_as_valid_utf8($s));
 
+echo "str_repeat:\n";
+$string = "a";
+$string_concat = str_repeat($string, 100);
+var_dump(zend_test_is_string_marked_as_valid_utf8($string_concat));
+$string = "\xff";
+$string_concat = str_repeat($string, 100);
+var_dump(zend_test_is_string_marked_as_valid_utf8($string_concat));
+
 ?>
 --EXPECT--
 Empty strings:
@@ -148,3 +156,6 @@ bool(true)
 Concatenation of objects:
 string(2) "zz"
 bool(true)
+str_repeat:
+bool(true)
+bool(false)