I was able to reproduce the coredump with various 5.8.x perls and with the latest bleadperl. I suspect there may be a bug in the optimisation that stores $1 and family only as a pair of pointers into the target string, but within $_ = $1; I'd expect the substring always to be extracted before the superstring is released so I'm not sure where the problem is likely to lie.

To reduce this to something perlbuggable, I'd suggest copying a few KB from /dev/urandom into a file to get something reproducible - probably do this a few times until you get a dataset that cores within the first 2 or 3 iterations - then start playing with the bytes in the file to simplify the description of the problem. For example, you may be able to replace each byte in the dataset with 'x' or 'y', such that the 'y's occur only where the regexp matches. Once the construction of the dataset can be reduced to a one-liner, debugging the problem should be straightforward.

Hugo

In reply to Re: Segmentation fault when doing /match/ and $_=$1 by hv
in thread Segmentation fault when doing /match/ and $_=$1 by ambrus

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