Re: [Request][Discussion] Double value as array key improvement

> 11 авг. 2017 г., в 15:53, Andrew Nester <newaltgroup@bk.ru> написал(а): > > >> On Aug 11, 2017, at 2:10 PM, Andrew Nester <newaltgroup@bk.ru> wrote: >> >> Hello everyone! >> >> I was working on following request >> https://bugs.php.net/bug.php?id=75053 which resulted in following >> pull request https://github.com/php/php-src/pull/2676 >> >> The problem here is following: when we’re using large numbers as array index when adding >> new elements it could overwrite already existing value. >> Assume we have 2 indexes 5076964154930102272 and 999999999999999999999999999999 with >> different value set for them. >> >> Because 999999999999999999999999999999 is larger than maximum long int number for 64-bit >> systems, it will be converted to double. (corresponding code here >> https://github.com/php/php-src/blob/master/Zend/zend_language_scanner.l#L1648) >> But when double value is used as array indexes, it is converted to long integer. (f.e., >> code is here >> https://github.com/php/php-src/blob/master/Zend/zend_execute.c#L1573) >> At this case it causes overflow and we’ve got index equal to 5076964154930102272 and as a >> result - we’re overwriting previously set value. >> >> My suggestion is following: >> 1) when double key is less than maximum possible long integer - convert it to integer >> 2) if it’s larger - convert it to string. >> >> That’s what implemented in proposed PR. >> >> Another possible option is just to throw warning in this case (proposed by Nikita Popov) >> >> I would happy to hear any feedback and suggestions about this solution. >> Thanks! > > Here is the alternative solution which emits E_WARNING in case of integer array index overflow. > https://github.com/php/php-src/pull/2677 My preferred solution is 2nd one (emitting warning) as it more obvious for users, doesn't break previous behaviour. Cheers, Andrew