Bug #78768 for Contextual-Return: using Carp with Contextual::Return causes "Incomplete caller override" message

Fri Aug 03 12:13:04 2012 FRAZER [...] cpan.org - Ticket created

Subject:

using Carp with Contextual::Return causes "Incomplete caller override" message

When using Contextual::Return with Carp, it displays the args as "** Incomplete caller override detected; @DB::args were not set **". Below are some one-liners to demonstrate the issue. The first two are Carp and Contextual::Return working independently and the third shows what happens when mixed. Show quoted text

> perl -MCarp -le 'sub f { Carp::confess("Forgive me..."); }; f();'

Forgive me... at -e line 1 main::f() called at -e line 1 Show quoted text

> perl -MContextual::Return -le 'sub f { print caller(); }; f();'

main-e1main::f1256 Show quoted text

> perl -MContextual::Return -MCarp -le 'sub f { Carp::confess("Forgive

me..."); }; f();' Forgive me... at -e line 1 main::f(** Incomplete caller override detected; @DB::args were not set **) called at -e line 1

Sat Aug 04 06:36:55 2012 nick [...] ccl4.org - Correspondence added

From:

nick [...] ccl4.org

on Fri Aug 03 12:13:04 2012, FRAZER wrote: Show quoted text

> When using Contextual::Return with Carp, it displays the args as "** > Incomplete caller override detected; @DB::args were not set **". > > Below are some one-liners to demonstrate the issue. The first two are > Carp and Contextual::Return working independently and the third shows > what happens when mixed.

> > perl -MCarp -le 'sub f { Carp::confess("Forgive me..."); }; f();'

> Forgive me... at -e line 1 > main::f() called at -e line 1

> > perl -MContextual::Return -le 'sub f { print caller(); }; f();'

> main-e1main::f1256

> > perl -MContextual::Return -MCarp -le 'sub f { Carp::confess("Forgive

> me..."); }; f();' > Forgive me... at -e line 1 > main::f(** Incomplete caller override detected; @DB::args were > not set **) called at -e line 1

This is Carp reporting problems with other code. It's not a bug in Carp - it's Carp avoiding subtle external bugs. In the case of Contextual::Return, I *think* that the problem is that instead of overriding CORE::caller, it tries to override Carp's routines, but doesn't do them all. The code starts like this: package Contextual::Return; # Fake out CORE::GLOBAL::caller and Carp very early... BEGIN { no warnings 'redefine'; my $fallback_caller = *CORE::GLOBAL::caller{CODE}; *CORE::GLOBAL::caller = sub { my ($uplevels) = shift || 0; if ($fallback_caller) { return $fallback_caller->($uplevels + 2 + $Contextual::Return::uplevel) if $Contextual::Return::uplevel; return $fallback_caller->($uplevels + 1); } else { return CORE::caller($uplevels + 2 + $Contextual::Return::uplevel) if $Contextual::Return::uplevel; return CORE::caller($uplevels + 1); } }; use Carp; my $real_carp = *Carp::carp{CODE}; my $real_croak = *Carp::croak{CODE}; *Carp::carp = sub { goto &{$real_carp} if !$Contextual::Return::uplevel; warn _in_context(@_); }; *Carp::croak = sub { goto &{$real_croak} if !$Contextual::Return::uplevel; die _in_context(@_); }; } I see carp and croak in there, but not cluck or confess. So I think that that's the code that needs changing to fix this problem. Nicholas Clark

Sat Aug 04 06:36:57 2012 The RT System itself - Status changed from 'new' to 'open'

Sat Aug 04 06:39:49 2012 nick [...] ccl4.org - Correspondence added

From:

nick [...] ccl4.org

On Sat Aug 04 06:36:55 2012, nick@ccl4.org wrote: Show quoted text

> This is Carp reporting problems with other code. It's not a bug in > Carp - it's Carp avoiding subtle external bugs. > > In the case of Contextual::Return, I *think* that the problem is that > instead of overriding CORE::caller, it tries to override Carp's > routines, but doesn't do them all. The code starts like this:

Show quoted text

> I see carp and croak in there, but not cluck or confess. So I think > that that's the code that needs changing to fix this problem.

Also, it seems that while I am getting notifications about bugs in Carp (which isn't actually my module, but I am familiar with the code in question) and can comment on the ticket, I don't have the privileges to transfer this ticket to the Contextual-Return queue. So I'm not quite sure what to do next. Nicholas Clark

Sat Aug 04 07:57:26 2012 rjbs [...] cpan.org - Queue changed from Carp to Contextual-Return

Sat Aug 04 07:57:56 2012 rjbs [...] cpan.org - Correspondence added

Subject:	Re: [rt.cpan.org #78768] using Carp with Contextual::Return causes "Incomplete caller override" message
Date:	Sat, 4 Aug 2012 07:57:45 -0400
To:	Nicholas Clark via RT <bug-Carp [...] rt.cpan.org>
From:	Ricardo Signes <rjbs [...] cpan.org>

* Nicholas Clark via RT <bug-Carp@rt.cpan.org> [2012-08-04T06:39:49] Show quoted text

> Also, it seems that while I am getting notifications about bugs in > Carp (which isn't actually my module, but I am familiar with the code > in question) and can comment on the ticket, I don't have the > privileges to transfer this ticket to the Contextual-Return queue. So > I'm not quite sure what to do next.

Done. -- rjbs

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Sun Aug 05 04:04:43 2012 damian [...] conway.org - Correspondence added

Subject:	Re: [rt.cpan.org #78768] using Carp with Contextual::Return causes "Incomplete caller override" message
Date:	Sun, 5 Aug 2012 18:03:54 +1000
To:	bug-Contextual-Return [...] rt.cpan.org
From:	Damian Conway <damian [...] conway.org>

Show quoted text

>> I don't have the privileges to transfer this ticket to the Contextual- >> Return queue. So I'm not quite sure what to do next.

> > Done.

...and patched ...and uploaded. Thank-you gentlemen! Damian

Tue Aug 07 14:41:23 2012 FRAZER [...] cpan.org - Correspondence added

I installed the latest version from CPAN and it appears to be working now. Thank you!

Tue Aug 07 14:41:24 2012 FRAZER [...] cpan.org - Status changed from 'open' to 'resolved'