Bug#966083: libdpkg-perl: Unexpected termination when loading vendor

[Guillem Jover]

Hi!

On Thu, 2020-07-23 at 03:20:21 +0300, Boian Bonev wrote:
> I have had the same problem last couple of days, finally could track
> what is happening:

Hah, just had finished fixing this locally, when I checked for the bug
number to slap to the commit message, saw this. :)

> - Exit.pm installs a handler for __DIE__

Yes, this was the main problem.

> I would suggest two things:
> 
> 1) Fix the code in Vendor.pm to avoid the global handler around eval
> and make the code work as initially planned (patch attached)

That would be a workaround as any other eval would also need to be
protected, which makes the exit handlers usage rather unsafe.

I'm attaching the fix I had prepared, which I'll be including in
1.20.6.

Thanks,
Guillem

diff --git i/scripts/Dpkg/Exit.pm w/scripts/Dpkg/Exit.pm
index 70a29b1a6..07f122fab 100644
--- i/scripts/Dpkg/Exit.pm
+++ w/scripts/Dpkg/Exit.pm
@@ -75,7 +75,10 @@ Run the registered exit handlers.
 =cut
 
 sub run_exit_handlers {
-    $_->() foreach (reverse @handlers);
+    while (my $handler = pop @handlers) {
+        $handler->();
+    }
+    _reset_exit_handlers();
 }
 
 sub _exit_handler {
@@ -83,7 +86,7 @@ sub _exit_handler {
     exit(127);
 }
 
-my @SIGNAMES = qw(INT HUP QUIT __DIE__);
+my @SIGNAMES = qw(INT HUP QUIT);
 my %SIGOLD;
 
 sub _setup_exit_handlers
@@ -101,6 +104,10 @@ sub _reset_exit_handlers
     }
 }
 
+END {
+    run_exit_handlers();
+}
+
 =back
 
 =head1 CHANGES
diff --git i/scripts/t/Dpkg_Exit.t w/scripts/t/Dpkg_Exit.t
index b4b15e405..663dfc96b 100644
--- i/scripts/t/Dpkg_Exit.t
+++ w/scripts/t/Dpkg_Exit.t
@@ -16,7 +16,7 @@
 use strict;
 use warnings;
 
-use Test::More tests => 5;
+use Test::More tests => 7;
 
 BEGIN {
     use_ok('Dpkg::Exit');
@@ -51,7 +51,17 @@ sub exit_handler {
     exit 0;
 }
 
+sub ini_handler {
+    pass('ini handler invoked');
+}
+
+sub end_handler {
+    pass('end handler invoked');
+}
+
+Dpkg::Exit::push_exit_handler(\&end_handler);
 Dpkg::Exit::push_exit_handler(\&exit_handler);
+Dpkg::Exit::push_exit_handler(\&ini_handler);
 
 kill 'INT', $$;