index: "git log" failures are fatal

While I've never seen "git log" fail on its own, it could happen
one day and we should be prepared to abort indexing when it
happens.

Beef up tests for t/spawn.t to ensure close() behaves
on popen_rd the way we expect it to.

1 files changed, 3 insertions, 2 deletions

diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index 1825da2c..02f313b0 100644
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -1128,6 +1128,7 @@ sub sync_prepare ($$$) {
                                 --no-notes --no-color --no-renames
                                 --diff-filter=AM), $range, '--', 'm');
                 ++$n while <$fh>;
+                close $fh or die "git log failed: \$?=$?";
                 $pr->("$n\n") if $pr;
                 $regen_max += $n;
         }
@@ -1195,7 +1196,7 @@ sub unindex ($$$$) {
                 unindex_oid($self, $git, $1, $unindexed);
         }
         delete $self->{reindex_pipe};
-        $fh = undef;
+        close $fh or die "git log failed: \$?=$?";
 
         return unless $sync->{-opt}->{prune};
         my $after = scalar keys %$unindexed;
@@ -1251,7 +1252,7 @@ sub index_epoch ($$$) {
                         mark_deleted($self, $sync, $git, $1);
                 }
         }
-        $fh = undef;
+        close $fh or die "git log failed: \$?=$?";
         delete $self->{reindex_pipe};
         update_last_commit($self, $git, $i, $cmt) if defined $cmt;
 }