Treat "+0" and "-0" as valid integers just like var_dump() does.

This fixes bug #54096.

Author: mj

ext/filter/logical_filters.c

@@ -80,6 +80,11 @@ static int php_filter_parse_int(const char *str, unsigned int str_len, long *ret
 			break;
 	}
 
+	if (*str == '0' && str + 1 == end) {
+		/* Special cases: +0 and -0 */
+		return 1;
+	}
+
 	/* must start with 1..9*/
 	if (str < end && *str >= '1' && *str <= '9') {
 		ctx_value = ((sign)?-1:1) * ((*(str++)) - '0');

ext/filter/tests/filter_data.phpt

@@ -10,6 +10,8 @@ precision=14
 /* Integer */
 $data = "-123";   var_dump(filter_var($data, FILTER_VALIDATE_INT));
 $data = "0";      var_dump(filter_var($data, FILTER_VALIDATE_INT));
+$data = "-0";     var_dump(filter_var($data, FILTER_VALIDATE_INT));
+$data = "+0";     var_dump(filter_var($data, FILTER_VALIDATE_INT));
 $data = "123";    var_dump(filter_var($data, FILTER_VALIDATE_INT));
 $data = -123;     var_dump(filter_var($data, FILTER_VALIDATE_INT));
 $data = 0;        var_dump(filter_var($data, FILTER_VALIDATE_INT));
@@ -46,6 +48,8 @@ $data = "";       var_dump(filter_var($data, FILTER_VALIDATE_BOOLEAN));
 --EXPECT--
 int(-123)
 int(0)
+int(0)
+int(0)
 int(123)
 int(-123)
 int(0)