Revert "revert vivication changes for now again"

This reverts commit 67b1704808e62f27210fe992df9c45b232fe9d5b.

Conflicts:

	Changes

1 files changed, 38 insertions, 13 deletions

diff --git a/lib/Package/Stash.pm b/lib/Package/Stash.pm
index 32e5d30..6c361c1 100644
--- a/lib/Package/Stash.pm
+++ b/lib/Package/Stash.pm
@@ -5,6 +5,10 @@ use warnings;
 
 use Carp qw(confess);
 use Scalar::Util qw(reftype);
+use Symbol;
+# before 5.12, assigning to the ISA glob would make it lose its magical ->isa
+# powers
+use constant BROKEN_ISA_ASSIGNMENT => ($] < 5.012);
 
 =head1 SYNOPSIS
 
@@ -230,21 +234,42 @@ sub get_package_symbol {
     my $namespace = $self->namespace;
 
     if (!exists $namespace->{$name}) {
-        # assigning to the result of this function like
-        #   @{$stash->get_package_symbol('@ISA')} = @new_ISA
-        # makes the result not visible until the variable is explicitly
-        # accessed... in the case of @ISA, this might never happen
-        # for instance, assigning like that and then calling $obj->isa
-        # will fail. see t/005-isa.t
-        if ($opts{vivify} && $type eq 'ARRAY' && $name ne 'ISA') {
-            $self->add_package_symbol($variable, []);
-        }
-        elsif ($opts{vivify} && $type eq 'HASH') {
-            $self->add_package_symbol($variable, {});
+        if ($opts{vivify}) {
+            if ($type eq 'ARRAY') {
+                if (BROKEN_ISA_ASSIGNMENT) {
+                    $self->add_package_symbol(
+                        $variable,
+                        $name eq 'ISA' ? () : ([])
+                    );
+                }
+                else {
+                    $self->add_package_symbol($variable, []);
+                }
+            }
+            elsif ($type eq 'HASH') {
+                $self->add_package_symbol($variable, {});
+            }
+            elsif ($type eq 'SCALAR') {
+                $self->add_package_symbol($variable);
+            }
+            elsif ($type eq 'IO') {
+                $self->add_package_symbol($variable, Symbol::geniosym);
+            }
+            elsif ($type eq 'CODE') {
+                confess "Don't know how to vivify CODE variables";
+            }
+            else {
+                confess "Unknown type $type in vivication";
+            }
         }
         else {
-            # FIXME
-            $self->add_package_symbol($variable)
+            if ($type eq 'CODE') {
+                # this effectively "de-vivifies" the code slot. if we don't do
+                # this, referencing the coderef at the end of this function
+                # will cause perl to auto-vivify a stub coderef in the slot,
+                # which isn't what we want
+                $self->add_package_symbol($variable);
+            }
         }
     }