Branch: refs/heads/blead
Home: https://github.com/Perl/perl5
Commit: 9e298ab597b2c6fc0741749d7e29119e2d6cd628
https://github.com/Perl/perl5/commit/9e298ab597b2c6fc0741749d7e29119e2d6cd628
Author: Richard Leach <richardle...@users.noreply.github.com>
Date: 2023-07-20 (Thu, 20 Jul 2023)
Changed paths:
M av.c
M t/op/array.t
Log Message:
-----------
Perl_av_extend_guts: Zero() trailing elements after unshift & resize
Since
https://github.com/Perl/perl5/commit/399fef93c903aedee05a74de780b57eeeb571b32,
trailing elements in an array that has been unshifted and resized
might not be properly Zero() initialized. This is because of faulty
arithmetic when calculating `to_null`, the number of elements to
initialize, when the array was only partially shifted.
This commit corrects the arithmetic, adds comments arount the
calculation of `to_null`, and adds a test based upon the case
provided in GH #21235.
The test added segfaults more reliably for me - almost every time -
than the originally supplied case. However, since it relies upon
uninitialized memory, it's probably still not deterministic and
somewhat dependent upon the choice of memory allocator.
Closes #21235
