Bug#777556: perl: regexp performance regression since 5.18

[Niko Tyni]

Package: perl
Version:: 5.20.1-5
Severity: serious
Tags: upstream
Forwarded: https://rt.perl.org/Ticket/Display.html?id=123743

This should possibly be considered a release critical performance
regression. Marking as 'serious' for now.

  (wheezy)$ seq -f "%01000.0f: 0c" 1000 | /usr/bin/time perl5.14.2 -ne '/.*:\s*ab/i'
  0.02user 0.00system 0:00.02elapsed 96%CPU (0avgtext+0avgdata 3260maxresident)k
  0inputs+0outputs (0major+168minor)pagefaults 0swaps
  
  (sid)$ seq -f "%01000.0f: 0c" 1000 | /usr/bin/time perl5.20.1 -ne '/.*:\s*ab/i'
  7.41user 0.00system 0:07.41elapsed 99%CPU (0avgtext+0avgdata 4100maxresident)k
  0inputs+0outputs (0major+204minor)pagefaults 0swaps
  
Upstream is working on a fix.
-- 
Niko Tyni   ntyni at debian.org