Document the tied/magical/shared array/hash non-autovivifying bug.

p4raw-id: //depot/perl@17221

diff --git a/ext/threads/shared/shared.pm b/ext/threads/shared/shared.pm
index c92bfe5..eeb9984 100644 (file)
--- a/ext/threads/shared/shared.pm
+++ b/ext/threads/shared/shared.pm
@@ -190,6 +190,10 @@ implemented in a future version of Perl.
 
 Does not support splice on arrays!
 
+Taking references to the elements of shared arrays and hashes does not
+autovivify the elements, and neither does slicing a shared array/hash
+over non-existent indices/keys autovivify the elements.
+
 =head1 AUTHOR
 
 Arthur Bergman E<lt>arthur at contiller.seE<gt>

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index c1f08fe..42e5dbf 100644 (file)
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -3337,6 +3337,15 @@ behaviour may be fixed at a later date.
 
 Self-tying of scalars and IO thingies works.
 
+=head2 Tied/Magical Array/Hash Elements Do Not Autovivify
+
+For normal arrays C<$foo = \$bar[1]> will assign C<undef> to
+C<$bar[1]> (assuming that it didn't exist before), but for
+tied/magical arrays and hashes such autovivification does not happen
+because there is currently no way to catch the reference creation.
+The same problem affects slicing over non-existent indices/keys of
+a tied/magical array/hash.
+
 =head2 Building Extensions Can Fail Because Of Largefiles
 
 Some extensions like mod_perl are known to have issues with