[PATCH 1/2] filter/rubylang: reuse altid entry from inbox object

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

This allows users to DRY up their config a bit and avoid
specifying altid twice when reusing the NNTP-centric msgmap
for [ruby-*:\d+] serial numbers.

My current work-in-progress ~/.public-inbox/config entry
for the ruby-core list is:

------8<-------
[publicinbox "ruby-core"]
	address = ruby-core@ruby-lang.org
	url = //public-inbox.org/ruby-core
	mainrepo = /path/to/ruby-core.git
	newsgroup = inbox.comp.lang.ruby.core
	watchheader = List-Id:<ruby-core.ruby-lang.org>
	altid = serial:ruby-core:file=msgmap.sqlite3
	watch = maildir:/path/to/Maildir/.INBOX.ruby
	filter = PublicInbox::Filter::RubyLang
---
 lib/PublicInbox/Filter/RubyLang.pm | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/PublicInbox/Filter/RubyLang.pm b/lib/PublicInbox/Filter/RubyLang.pm
index ec4bc32..5240e8d 100644
--- a/lib/PublicInbox/Filter/RubyLang.pm
+++ b/lib/PublicInbox/Filter/RubyLang.pm
@@ -15,10 +15,13 @@ sub new {
 	my ($class, %opts) = @_;
 	my $altid = delete $opts{-altid};
 	my $self = $class->SUPER::new(%opts);
+	my $ibx = $self->{-inbox};
 	# altid = serial:ruby-core:file=msgmap.sqlite3
+	if (!$altid && $ibx && $ibx->{altid}) {
+		$altid ||= $ibx->{altid}->[0];
+	}
 	if ($altid) {
 		require PublicInbox::MID; # mid_clean
-		my $ibx = $self->{-inbox};
 		require PublicInbox::AltId;
 		$self->{-altid} = PublicInbox::AltId->new($ibx, $altid, 1);
 	}
-- 
EW