Fwd: $^E bug and perl 5.8.0

[Richard Cook]

Begin forwarded message:

(For the porters: the bug is that this:

	% perl -le '$^E = -1728; print $^E+0 for 0,1'

Should return this:

        -1728
        -1728
But in some cases, returns this:

        -1728
        22
Odd.)
this is because perl's print writes to stdout, and that usually uses
the linux implementation of C's stdio, and stdio uses isatty(3) on
stdout at the first write to decide if stdout is a terminal (to
decide what kind of output buffering to use).  and isatty is usually
implemented by trying some kernel system operation on the file
descriptor, an operation that will fail if the file descriptor is
not a terminal.  in that case, the kernel operation fails and sets
errno=22 (EINVAL) to indicate why it failed.