Garrett Goebel wrote:
Geoffrey Young wrote: > > That's when you use Apache::compat, doing the mp1 syntax. > > In mp2-speak that would be: > > > > $r->err_headers_out->add('Set-Cookie' => $packed_cookie); > > $r->headers_out->set('Location' => $url); > > $r->status(REDIRECT); > > > > notice that you don't need to call $r->send_http_header, it > > doesn't exist in mp2. > > not to mention it's entirely unnecessary (and undesirable) to > send headers on error responses such as redirects.
Why?
Appendix A.7 from the Stas' Practical mod_perl book states:
> You should use err_headers_out( ), not headers_out( ), > when you want to send cookies in a REDIRECT response or > in any other non-2XX response
that's correct, but setting the headers is entirely different than sending them.
And gives the following recipe:
Example A-3. redirect_cookie.pl use Apache::Constants qw(REDIRECT OK); my $r = shift; # prepare the cookie in $cookie $r->err_headers_out->add('Set-Cookie' => $cookie); $r->headers_out->set(Location => $location); $r->status(REDIRECT); $r->send_http_header; return OK;
How would you have written it?
the example is wrong - it should not have send_http_header() in it.
if you execute that script over telnet, you'll see two sets of headers.
apache automatically sends headers on errors - that's how you are able to get standard 500 pages, etc.
> and you should never set $r->status from a handler - for
> Registry scripts it's ok, since we use it as a hack to get
> around some things, but handlers should never manipulate the
> value of $r->status.
Why is that?
if r->status is not HTTP_OK (200) then apache thinks that an ErrorDocument has _also_ thrown an error, and it thus ends what would otherwise be a recursive cycle of errors. by messing with r->status, you mess up Apache's internal bookkeeping wrt the error document cycle.
--Geoff
/me sliently points to recipe 3.13 in the cookbook, too :)
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