better implementation of change#3326; open(local $foo,...) now

allowed in addition to any uninitialized variable, for consistency
with how autovivification works elsewhere; add code to use the
variable name as the name of the handle for simple variables, so
that diagnostics report the handle: "... at - line 1, <$foo> line 10."

p4raw-link: @3326 on //depot/perl: 853846ea710f8feaed8c98b358bdc8967dd522d2

p4raw-id: //depot/perl@4639

1 files changed, 8 insertions, 5 deletions

diff --git a/pod/perldelta.pod b/pod/perldelta.pod
index 12d26841a1..47a9eb13c5 100644
--- a/pod/perldelta.pod
+++ b/pod/perldelta.pod
@@ -360,11 +360,14 @@ The length argument of C<syswrite()> has become optional.
 
 =head2 Filehandles can be autovivified
 
-The construct C<open(my $fh, ...)> can be used to create filehandles
-more easily.  The filehandle will be automatically closed at the end
-of the scope of $fh, provided there are no other references to it.  This
-largely eliminates the need for typeglobs when opening filehandles
-that must be passed around, as in the following example:
+Similar to how constructs such as C<$x->[0]> autovivify a reference,
+open() now autovivifies a filehandle if the first argument is an
+uninitialized variable.  This allows the constructs C<open(my $fh, ...)> and
+C<open(local $fh,...)> to be used to create filehandles that will
+conveniently be closed automatically when the scope ends, provided there
+are no other references to them.  This largely eliminates the need for
+typeglobs when opening filehandles that must be passed around, as in the
+following example:
 
     sub myopen {
         open my $fh, "@_"