I have a small script which takes some html file as its input and strips out certain chunks of the html using a search and replace regexp prior to spitting it out.

Here's a larely reduced and simplified version of the script (done so as to narrow down to the actual buggy spot): 
use strict;

open(IN,"page.html");
$/ = undef;
my $content = <IN>;
close(IN);

print "size: ". length($content) ."\n";

# either of the two regexp cause seg fault!
# $content =~ s/^Set-Cookie: .*$//mgi;   # CORE DUMP

# Also trying to remove the /g option here. 
# Still core dumps.
# $content =~ s/^Set-Cookie: .*$//mi;    # CORE DUMP

# these work fine though...
$content =~ s/^Cache-Control: .*$//mi;   # OK

print "Done.\n";

[download]
Try uncommenting either of the two lines marked # CORE DUMP and the script will core dump.
---------------- 
size: 67877
Segmentation fault (core dumped)

[download]
I'm also puzzled over why the second CORE DUMP line still fails when I remove the /g regexp option? As I look at the OK line and compare it to the CORE DUMP line just above it (also without the /g option), I hardly note any startling difference.

This script would only core dump on a server where I have perl 5.6.0 installed. The same script works just fine with perl 5.6.1

Aware of any difference?

Thanks for help..

Update: Just played with the page.html file and added 'Set-Cookie: foobar' line and the script didn't core dump! So, it only does so when there are no 'Set-Cookie: .*' line in the source file. (note: there was a 'Cache-Control: .*' line there already.. I didn't try removing it to see if the script would then core dump, though)

"There is no system but GNU, and Linux is one of its kernels." -- Confession of Faith

In reply to Mystereous regexp core dump by vladb

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