mirror of
https://github.com/php/php-src.git
synced 2026-04-15 20:11:02 +02:00
60ace13f9c
RAND_RANGE_BADSCALING() invokes undefined behavior when (max - min) > ZEND_LONG_MAX, because the intermediate `double` might not fit into `zend_long`. Fix this by inlining a fixed version of the macro into Mt19937's range() function. Fixing the macro itself cannot be done in the general case, because the types of the inputs are not known. Instead of replacing one possibly broken version with another possibly broken version, the macro is simply left as is and should be removed in a future version. The fix itself is simple: Instead of storing the "offset" in a `zend_long`, we use a `zend_ulong` which is capable of storing the resulting double by construction. With this fix the implementation of this broken scaling is effectively identical to the implementation of php_random_range from a data type perspective, making it easy to verify the correctness. It was further empirically verified that the broken macro and the fix return the same results for all possible values of `r` for several distinct pairs of (min, max). Fixes GH-9190 Fixes GH-9191