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

> 13 авг. 2017 г., в 21:39, Andrew Nester <andrew.nester.dev@gmail..com> > написал(а): > > > >> 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 Hello internals! I was working on solution for the problem of double to int conversion for array indices and would like to create an RFC for proposed solution - emitting warning when integer overflow happens during double to int conversion. Does it look like good idea? Thanks!