Apache::Registry should allow script to _only_ set return code

[Charles Levert]

Hi.

[ I use Apache 1.3.9 and mod_perl 1.21. ]

I believe that there is a difference between the following two
behaviors for an Apache module handler:

        -- setting the request's status field to a new value and also
        returning that value;

        -- just returning a value without assigning it to the
        request's status field.

It's an useful thing that a mod_perl script (what
Apache::Registry::handler calls) be able to decide that, e.g.,
HTTP_NOT_FOUND, should be returned to the browser and just return
then.

        # example mod_perl script

        use Apache::Constants ':response';
        my $r = Apache->request;

        if (...) {
                $r->status(NOT_FOUND);
                return;
        }

        $r->content_type('text/html');
        ...

We then expect that the normal ErrorDocument, as configured, should be
returned in that case.  However, this is not what happens because
Apache::Registry chooses the first behavior listed above and so an
HTTP_NOT_FOUND also seem to affect the ErrorDocument then.  The useful
behavior would be the second one listed above.

Ideally, a method such as $r->return_value could be defined,
independently of $r->status, and its argument could then be used when
Apache::Registry::handler returns.  An other possibily which can
probably be ruled out for compatibily with CGI scripts and other
reasons is to use the return value from the mod_perl script itself.

I have appended a patch to Apache::Registry below which I believe to
be an acceptable solution for now.  (It really disallows a script to
set the status field using the possibly changed status field as return
value.)

Your comments are welcome.  Do you think that such a change or what I
mention above ($r->return_value) should make it in the main
distribution of mod_perl?


Charles


========================================================================
--- Registry.pm.orig-1.21       Tue Jan 12 21:56:34 1999
+++ Registry.pm Thu Jan 13 14:50:56 2000
@@ -131,6 +131,8 @@
            $Apache::Registry->{$package}{'mtime'} = $mtime;
        }
 
+       my $old_status = $r->status;
+
        my $cv = \&{"$package\::handler"};
        eval { &{$cv}($r, @_) } if $r->seqno;
        $r->chdir_file("$Apache::Server::CWD/");
@@ -155,7 +157,9 @@
 #              return REDIRECT;
 #          }
 #      }
-       return $r->status;
+       my $return_value = $r->status;
+       $r->status($old_status);
+       return $return_value;
     } else {
        return NOT_FOUND unless $Debug && $Debug & 2;
        return Apache::Debug::dump($r, NOT_FOUND);
========================================================================