[PATCH 1/2] v2writable: detect shard count for ExtSearchIdx properly

[Eric Wong <e@80x24.org>]

Otherwise, any explicitly set shard counts were ignored and
we'd be counting CPUs every single time.
---
 lib/PublicInbox/V2Writable.pm | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index a3938b56..e9a43000 100644
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -65,13 +65,21 @@ sub nproc_shards ($) {
 
 sub count_shards ($) {
 	my ($self) = @_;
-	$self->{ibx} ? do {
+	if (my $ibx = $self->{ibx}) {
 		# always load existing shards in case core count changes:
 		# Also, shard count may change while -watch is running
-		my $srch = $self->{ibx}->search or return 0;
-		delete $self->{ibx}->{search};
+		my $srch = $ibx->search or return 0;
+		delete $ibx->{search};
 		$srch->{nshard} // 0
-	} : $self->{nshard}; # self->{nshard} is for ExtSearchIdx
+	} else { # ExtSearchIdx
+		$self->{nshard} // do {
+			if ($self->xdb_sharded) {
+				$self->{nshard} // die 'BUG: {nshard} unset';
+			} else {
+				0;
+			}
+		}
+	}
 }
 
 sub new {