perl.c: Don't read possibly zapped memory

See https://rt.perl.org/Ticket/Display.html?id=123748

The return of getenv() is a pointer to static storage which can legally
be overwritten at any time by other calls to access the environment,
even even another getenv().  (What actually happens varies from platform
to platform.)  Results of getenv() therefore either have to be acted on
immediately or copied to a safe area.  This commit does the latter for
this call in perl.c.  The static area was being held on to even into the
function call moreswitches() which does environmen handling, so was
vulnerable to this bug.

0 files changed, 0 insertions, 0 deletions