[PATCH 1/2] thread: reduce indentation level

[PATCH 1/2] thread: reduce indentation level

[Eric Wong]

This should reduce differences from the original Mail::Thread
code and hopefully make things easier-to-follow.
---
 lib/PublicInbox/SearchThread.pm | 38 +++++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/lib/PublicInbox/SearchThread.pm b/lib/PublicInbox/SearchThread.pm
index 003a8d1..c6bd999 100644
--- a/lib/PublicInbox/SearchThread.pm
+++ b/lib/PublicInbox/SearchThread.pm
@@ -49,27 +49,27 @@ sub _add_message ($$) {
 	$this->{smsg} = $smsg;
 
 	# B. For each element in the message's References field:
+	defined(my $refs = $smsg->{references}) or return;
+
 	my $prev;
-	if (defined(my $refs = $smsg->{references})) {
-		foreach my $ref ($refs =~ m/<([^>]+)>/g) {
-			# Find a Container object for the given Message-ID
-			my $cont = _get_cont_for_id($self, $ref);
-
-			# Link the References field's Containers together in
-			# the order implied by the References header
-			#
-			# * If they are already linked don't change the
-			#   existing links
-			# * Do not add a link if adding that link would
-			#   introduce a loop...
-			if ($prev &&
-				!$cont->{parent} &&  # already linked
-				!$cont->has_descendent($prev) # would loop
-			   ) {
-				$prev->add_child($cont);
-			}
-			$prev = $cont;
+	foreach my $ref ($refs =~ m/<([^>]+)>/g) {
+		# Find a Container object for the given Message-ID
+		my $cont = _get_cont_for_id($self, $ref);
+
+		# Link the References field's Containers together in
+		# the order implied by the References header
+		#
+		# * If they are already linked don't change the
+		#   existing links
+		# * Do not add a link if adding that link would
+		#   introduce a loop...
+		if ($prev &&
+			!$cont->{parent} &&  # already linked
+			!$cont->has_descendent($prev) # would loop
+		   ) {
+			$prev->add_child($cont);
 		}
+		$prev = $cont;
 	}
 
 	# C. Set the parent of this message to be the last element in
-- 
EW

[PATCH 2/2] thread: fix parent/child relationships

[Eric Wong]

The ordering change in add_child is critical if $self == $parent,
and has_descendent can be simplified by walking upwards from
the child instead of downwards from the parent.

This fixes a threading regression introduced in
commit 30100c46326e2eac275e0af13116636701d2537e
("thread: use hash + array instead of hand-rolled linked list")
---
 lib/PublicInbox/SearchThread.pm | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/lib/PublicInbox/SearchThread.pm b/lib/PublicInbox/SearchThread.pm
index c6bd999..24a56d2 100644
--- a/lib/PublicInbox/SearchThread.pm
+++ b/lib/PublicInbox/SearchThread.pm
@@ -104,27 +104,21 @@ sub add_child {
 	  if $self == $child;
 
 	my $cid = $child->{id};
-	$self->{children}->{$cid} = $child;
 
 	# reparenting:
 	if (defined(my $parent = $child->{parent})) {
 		delete $parent->{children}->{$cid};
 	}
 
+	$self->{children}->{$cid} = $child;
 	$child->{parent} = $self;
 }
 
 sub has_descendent {
-	my ($cur, $child) = @_;
-	my %seen;
-	my @q = ($cur->{parent} || $cur);
-
-	while (defined($cur = shift @q)) {
-		return 1 if $cur == $child;
-
-		if (!$seen{$cur}++) {
-			push @q, values %{$cur->{children}};
-		}
+	my ($self, $child) = @_;
+	while ($child) {
+		return 1 if $self == $child;
+		$child = $child->{parent};
 	}
 	0;
 }
-- 
EW