| Subject: | CGI objects access global data |
(Tested with v3.05 under apache on Linux.)
Consider two scripts:
# a
use CGI;
use Storable qw(nstore);
my $q = new CGI();
nstore($q, "/tmp/stash");
print $q->header(-content_type => 'text/plain'), $q->self_url();
# b
use CGI;
use Storable qw(retrieve);
my $q = new CGI();
my $q2 = retrieve("/tmp/stash");
print $q->header(-content_type => 'text/plain'), $q->self_url(), "\n", $q2->self_url();
Invoking a, then b, we get the results,
http://host/path/a
and then
http://host/path/b
http://host/path/b
This is broken -- the latter should print
http://host/path/a
http://host/path/b
The reason is the CGI::url() extracts information from $ENV. So q2 thinks that its URL is the URL under which the script was invoked, not the URL under which it was saved.
(Why does it matter? Well, I came across this in a case where I wanted to stash some data to be able to reinvoke a script via POST later on. I can imagine other cases where the same thing might arise.)
I guess the easiest fix is to save the bits of %ENV that matter in the CGI object, rather than accessing the global %ENV.