Patch for ModPerl::Util to make Apache::Reload and Class::DBI cooperate

[Ben Tilly <bt...@gmail.com>]

Currently in modperl 2 you cannot get Apache::Reload and Class::DBI to
cooperate properly.  The problem is that Apache::Reload wipes out the
CODE slot  by doing an undef, which leaves a non-working code
reference.  Therefore UNIVERSAL::can and *foo{CODE} will both say that
there is a method/function there, but Bad Things happen if you try to
call it.

This confuses Class::DBI (and probably some other modules) on a reload.

The attached patch from Steve Caldwell and me fixes that.  (There are
other issues as well, but Class::Data::Reloadable takes care of them.)
 Unfortunately this does not preserve the GLOB slot as the old code
did, but since we're skipping stashes, I don't think that that is
likely to cause problems.

Aslo note that we are explicitly closing filehandles.  I don't know
why the old code was doing so.  Personally I'd be inclined not to -
Perl will close a filehandle when the last reference to it goes away,
and we're leaving a trap for anyone who aliases STDIN, STDOUT or
STDERR to a local filehandle.  But I'm trying to not change behaviour
without knowing the reason for the old, so I'll leave that for someone
else to remove.

Cheers,
Ben

--- /usr/lib/perl5/ModPerl/Util.pm	2005-08-11 22:43:50.000000000 -0700
+++ lib/perl5/ModPerl/Util.pm	2005-09-12 13:34:33.282868768 -0700
@@ -38,46 +38,22 @@
     no strict 'refs';
     my $tab = \%{ $package . '::' };
 
-    # below we assign to a symbol first before undef'ing it, to avoid
-    # nuking aliases. If we undef directly we may undef not only the
-    # alias but the original function as well
-
     for (keys %$tab) {
         #Skip sub stashes
         next if /::$/;
 
         my $fullname = join '::', $package, $_;
-        # code/hash/array/scalar might be imported make sure the gv
-        # does not point elsewhere before undefing each
-        if (%$fullname) {
-            *{$fullname} = {};
-            undef %$fullname;
-        }
-        if (@$fullname) {
-            *{$fullname} = [];
-            undef @$fullname;
-        }
-        if ($$fullname) {
-            my $tmp; # argh, no such thing as an anonymous scalar
-            *{$fullname} = \$tmp;
-            undef $$fullname;
-        }
-        if (defined &$fullname) {
-            no warnings;
-            local $^W = 0;
-            if (defined(my $p = prototype $fullname)) {
-                *{$fullname} = eval "sub ($p) {}";
-            }
-            else {
-                *{$fullname} = sub {};
-            }
-            undef &$fullname;
-        }
+
+        # I'm not sure why we're closing the filehandles, but the version
+        # I replaced did the same
         if (*{$fullname}{IO}) {
             if (fileno $fullname) {
                 close $fullname;
             }
         }
+
+        *{$fullname} = do {local *{$fullname}};
+
     }
 
     #Wipe from %INC