v2writable: add DEBUG_DIFF env support

This can help us track down some differences during import,
if needed.

diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index 8e1363ea732895da043cb5080502d65afdbc66b1..30ca9cec47ce8474250119b3d76dbd7dd1c99be1 100644 (file)
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -406,6 +406,26 @@ sub import_init {
        $self->{im} = $im;
 }
 
+# XXX experimental
+sub diff ($$$) {
+       my ($mid, $cur, $new) = @_;
+       use File::Temp qw(tempfile);
+       use PublicInbox::Spawn qw(spawn);
+
+       my ($ah, $an) = tempfile('email-cur-XXXXXXXX');
+       print $ah $cur->as_string or die "print: $!";
+       close $ah or die "close: $!";
+       my ($bh, $bn) = tempfile('email-new-XXXXXXXX');
+       print $bh $new->as_string or die "print: $!";
+       close $bh or die "close: $!";
+       my $cmd = [ qw(diff -u), $an, $bn ];
+       print STDERR "# MID conflict <$mid>\n";
+       my $pid = spawn($cmd, undef, { 1 => 2 });
+       defined $pid or die "diff failed to spawn $!";
+       waitpid($pid, 0) == $pid or die "diff did not finish";
+       unlink($an, $bn);
+}
+
 sub lookup_content {
        my ($self, $mime, $mid) = @_;
        my $ibx = $self->{-inbox};
@@ -427,6 +447,10 @@ sub lookup_content {
                        $found = $smsg;
                        return 0; # break out of loop
                }
+
+               # XXX DEBUG_DIFF is experimental and may be removed
+               diff($mid, $cur, $mime) if $ENV{DEBUG_DIFF};
+
                1; # continue
        });
        $found;