From andrew.gregory.8@gmail.com

Following commit 7bdb4ff, when open is called with a scalar ref, the filehandle has a refcount of 2, preventing it from being closed when the variable goes out of scope.

{
  use B;
  my $fh;
  open ${ \$fh }, '<', $^X;
  print B​::svref_2object( $fh )->REFCNT; # prints 2
}

This pattern is used by modules such as Win32​::LongPath (https://github.com/rdboisvert/Win32-LongPath/blob/8faa348/lib/Win32/LongPath.pm#L485).

From @cpansprout

On Fri Mar 11 07​:38​:26 2016, agregory wrote​:

Following commit 7bdb4ff, when open
is called with a scalar ref, the filehandle has a refcount of 2,
preventing it from being closed when the variable goes out of scope.

{
use B;
my $fh;
open ${ \$fh }, '<', $^X;
print B​::svref_2object( $fh )->REFCNT; # prints 2
}

This pattern is used by modules such as Win32​::LongPath
(https://github.com/rdboisvert/Win32-
LongPath/blob/8faa348/lib/Win32/LongPath.pm#L485).

Ever since Perl 5.6, this type of open has vivified a glob with a name like *_GEN_0. In your example, \*_GEN_0 == $fh will be true after opening the handle. The reason it is not freed when $fh goes out of scope is that the stash holds a reference to the handle, too.

There are two conceivable ways to solve this.

1) Don’t vivify a handle in the stash, but create an ‘anonymous’ handle named __ANONIO__, which already happens with other variations of the syntax.

2) Vivify a typeglob, but not in the stash (like __ANONIO__), but call in _GEN_0.

Whether we can do either depends on the answers to these questions​:

• Is anybody depending on the name? (It certainly makes debugging easier than having multiple handles all named __ANONIO__.)

• Is anybody depending on being able to look up the name in the stash and find that same handle?

I don’t know the answers to those questions, which makes it hard to decide how to proceed. I would like to think that the answer to the second question is no (that nobody needs to access such filehandles by name).

--

Father Chrysostomos

The RT System itself - Status changed from 'new' to 'open'