[perl #37526] multiple encodings causes "panic: sv_setpvn called with negative strlen"

In 5.16.0, this program:

  use encoding 'iso-8859-1';
  binmode STDOUT, ':encoding(iso-8859-1)' or die "binmode:$!";
  print "\xe1", "\n";

prints:

  "\x{fffd}" does not map to iso-8859-1 at test7.pl line 3.
  \x{fffd}

and changing the last line to:

  print "x\xe1", "\n";

yields:

  "\x{fffd}" does not map to iso-8859-1 at test7.pl line 3.
  x\x{fffd}

Is this the expected behavior? I'm not entirely sure why it would be
printing a literal '\x{fffd}'.

-doy

---
via perlbug:  queue: perl5 status: open
https://rt.perl.org:443/rt3/Ticket/Display.html?id=37526

• [perl #37526] multiple encodings causes "panic: sv_setpvn called with negative strlen" by Jesse Luehrs via RT
• Re: [perl #37526] multiple encodings causes "panic: sv_setpvn calledwith negative strlen" by Leon Timmermans
• Re: [perl #37526] multiple encodings causes "panic: sv_setpvn calledwith negative strlen" by Eric Brine
• Re: [perl #37526] multiple encodings causes "panic: sv_setpvn calledwith negative strlen" by Eric Brine
• Re: [perl #37526] multiple encodings causes "panic: sv_setpvn calledwith negative strlen" by Nicholas Clark
• Re: [perl #37526] multiple encodings causes "panic: sv_setpvn calledwith negative strlen" by Aristotle Pagaltzis