v2writable: don't verify tip if reindexing

We only rely on git-rev-parse to resolve symbolic names ("HEAD")
to a SHA-* git commit ID.  We'll assume any git commit IDs we
get from SQLite DBs are valid and let "git-log" fail if it
isn't.

1 files changed, 6 insertions, 4 deletions

diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index ca52874b..f20b5c7f 100644
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -1104,12 +1104,14 @@ sub sync_prepare ($$) {
                 -d $git_dir or next; # missing epochs are fine
                 my $git = PublicInbox::Git->new($git_dir);
                 my $unit = { git => $git, epoch => $i };
+                my $tip;
                 if ($reindex_heads) {
-                        $head = $reindex_heads->[$i] or next;
+                        $tip = $head = $reindex_heads->[$i] or next;
+                } else {
+                        $tip = $git->qx(qw(rev-parse -q --verify), $head);
+                        next if $?; # new repo
+                        chomp $tip;
                 }
-                chomp(my $tip = $git->qx(qw(rev-parse -q --verify), $head));
-                next if $?; # new repo
-
                 my $range = log_range($sync, $unit, $tip) or next;
                 # can't use 'rev-list --count' if we use --diff-filter
                 $pr->("$pfx $i.git counting $range ... ") if $pr;