searchidx: avoid holding Xapian lock in cat-file

We must ensure cat-file process is launched before Xapian
grabs lock, too.  Our use of "git cat-file --batch" has
the same problem as "git log" did, (which was fixed in
commit 3713c727cda431a0dc2865a7878c13ecf9f21851)
"searchidx: release Xapian FDs before spawning git log"

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index f47bc439..59c27470 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -39,7 +39,7 @@ sub _bidi_pipe {
 sub cat_file {
         my ($self, $obj, $ref) = @_;
 
-        $self->_bidi_pipe(qw(--batch in out pid));
+        batch_prepare($self);
         $self->{out}->print($obj, "\n") or fail($self, "write error: $!");
 
         my $in = $self->{in};
@@ -89,6 +89,8 @@ sub cat_file {
         $rv;
 }
 
+sub batch_prepare ($) { _bidi_pipe($_[0], qw(--batch in out pid)) }
+
 sub check {
         my ($self, $obj) = @_;
         $self->_bidi_pipe(qw(--batch-check in_c out_c pid_c));