select() sometimes returns invalid string

The return value from select() is sometimes a string, and sometimes a
globref.  It was originally always a string, but typeglobs not to be
found under their names in their stashes started being returned as
references in 5.002 beta 1 (4633a7c4b).  The logic is a little faulty,
though, as sometimes the name that is returned cannot be used to find
the glob:

$ perl -le '
    open "foo::bar", ">/dev/ttys009";
    select foo::bar;
    my $handle = \*foo::bar;
    my $stash = \%foo::bar;
    *foo:: = *bar::;
    print "hello";
    select select;
    print "hello" or warn $!
'
Bad file descriptor at -e line 9.

In this example, /dev/ttys009 is another terminal window.  "hello"
only appears once, not twice.

1 files changed, 9 insertions, 1 deletions

diff --git a/t/op/select.t b/t/op/select.t
index 7c27f6ff25..06caf1ddfd 100644
--- a/t/op/select.t
+++ b/t/op/select.t
@@ -5,7 +5,7 @@ BEGIN {
     require './test.pl';
 }
 
-plan reverse 7;
+plan reverse 8;
 
 
 open my $fh, "test.pl" or die "$0 unfortunately cannot open test.pl: $!";
@@ -17,3 +17,11 @@ is select, $fh, 'the ref returned references the right referent';
 is select(STDOUT), $fh, 'select previous ref when setting to bareword';
 is select, 'main::STDOUT', 'switching back to STDOUT';
 is ref\select, 'SCALAR', 'and STDOUT is a plain string';
+
+open foo::bar, "test.pl" or die "$0 sadly cannot open test.pl: $!";
+select foo::bar;
+$handle = \*foo::bar;
+$stash = \%foo::;
+*foo:: = *bar::;
+is select, $handle,
+    'select returns ref for glob whose stash has been detached';