X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=lib%2FPublicInbox%2FThread.pm;h=8af94616f73d85edeaa50496dccb990c8c511906;hb=08913d1b05e32a7415cbe8afc3c229d108817de8;hp=7dabf2439927ee2a6546b3218d060b109a999dc4;hpb=55ff8f0893e1a1d57463861e0599717744f490bf;p=public-inbox.git

diff --git a/lib/PublicInbox/Thread.pm b/lib/PublicInbox/Thread.pm
index 7dabf243..8af94616 100644
--- a/lib/PublicInbox/Thread.pm
+++ b/lib/PublicInbox/Thread.pm
@@ -1,5 +1,14 @@
 # subclass Mail::Thread and use this to workaround a memory leak
 # Based on the patch in: https://rt.cpan.org/Public/Bug/Display.html?id=22817
+#
+# Additionally, workaround for a bug where $walk->topmost returns undef:
+# - http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=795913
+# - https://rt.cpan.org/Ticket/Display.html?id=106498
+#
+# And avoid recursion in recurse_down:
+# - https://rt.cpan.org/Ticket/Display.html?id=116727
+# - http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=833479
+#
 # License differs from the rest of public-inbox (but is compatible):
 # This library is free software; you can redistribute it and/or modify
 # it under the same terms as Perl itself.
@@ -7,6 +16,20 @@ package PublicInbox::Thread;
 use strict;
 use warnings;
 use base qw(Mail::Thread);
+# WARNING! both these Mail::Thread knobs were found by inspecting
+# the Mail::Thread 2.55 source code, and we have some monkey patches
+# in PublicInbox::Thread to fix memory leaks.  Since Mail::Thread
+# appears unmaintained, I suppose it's safe to depend on these
+# variables for now:
+{
+	no warnings 'once';
+	# we want strict threads to expose (and hopefully discourage)
+	# use of broken email clients
+	$Mail::Thread::nosubject = 1;
+	# Keep ghosts with only a single direct child,
+	# don't hide that there may be missing messages.
+	$Mail::Thread::noprune = 1;
+}
 
 if ($Mail::Thread::VERSION <= 2.55) {
 	eval q(sub _container_class { 'PublicInbox::Thread::Container' });
@@ -19,4 +42,45 @@ use base qw(Mail::Thread::Container);
 use Scalar::Util qw(weaken);
 sub parent { @_ == 2 ? weaken($_[0]->{parent} = $_[1]) : $_[0]->{parent} }
 
+sub topmost {
+	$_[0]->SUPER::topmost || PublicInbox::Thread::CPANRTBug106498->new;
+}
+
+# non-recursive version of recurse_down to avoid stack depth warnings
+sub recurse_down {
+	my ($self, $callback) = @_;
+	my %seen;
+	my @q = ($self);
+	while (my $cont = shift @q) {
+		$seen{$cont}++;
+		$callback->($cont);
+
+		if (my $next = $cont->next) {
+			if ($seen{$next}) {
+				$cont->next(undef);
+			} else {
+				push @q, $next;
+			}
+		}
+		if (my $child = $cont->child) {
+			if ($seen{$child}) {
+				$cont->child(undef);
+			} else {
+				push @q, $child;
+			}
+		}
+	}
+}
+
+# ref:
+# - http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=795913
+# - https://rt.cpan.org/Ticket/Display.html?id=106498
+package PublicInbox::Thread::CPANRTBug106498;
+use strict;
+use warnings;
+
+sub new { bless {}, $_[0] }
+
+sub simple_subject {}
+
 1;