Apache2::Reload problem (ModPerl::Util bug)

[Mark]

In 2.0.0, if there are heirarchical packages, and Apache2::Reload is
configured to reload the 'parent', it blows away the 'children' package
namespaces (and doesn't reload the children.)  For example, if @INC has:

Fubar.pm
Fubar/Child.pm

And Apache2::Reload reloads package Fubar, it blows away
Fubar::Child::* and only reloads file Fubar.pm.   Only a server
restart can recover from this point.

The actual unloading work is done by ModPerl::Util::unload_package(),
whose behavior is contrary to the docs, which say:

  "unload_package()" takes care to leave sub-stashes intact while
  deleting the requested stash. So for example if "CGI" and "CGI::Carp"
  are loaded, calling "unload_package('CGI')" won't affect "CGI::Carp".


I only partly understand how unload_package() works, but it seems to
just iterate over symbols in the package and blow them away, without
regard for the actual file from which the symbol was instantiated.

I tried modifying the code to skip over symbols that correspond
to a key in %INC, which seems logical and works correctly in my tests,
but may not be a complete or perfect solution for reasons beyond
my current testing/thinking.  However, in my tests, it works correctly
if either the parent package, child package, or both are modified.

Comments/suggestions about the correctness of this patch requested.

Thanks.


*** ./blib/lib/ModPerl/Util.pm  2005-05-22 10:14:19.000000000 -0700
--- /usr/lib/perl5/site_perl/5.8.5/i686-linux/ModPerl/Util.pm   2005-05-29 
10:09:02.000000000 -0700
***************
*** 36,55 ****
--- 36,58 ----
  sub unload_package_pp {
      my $package = shift;
      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 %$tab) {
+         if (my ($subpackage) = /(.*)::/) {
+             next if exists $INC{"$package/$subpackage.pm"};
+         }
          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;