v2: generate better Message-IDs for duplicates

[public-inbox.git] / lib / PublicInbox / Import.pm

diff --git a/lib/PublicInbox/Import.pm b/lib/PublicInbox/Import.pm
index 9e8900f3e6f86d2ce50576039654e75cad104120..c7a96e1eabcc1214e6cdc61572ba6ed70db64750 100644 (file)
--- a/lib/PublicInbox/Import.pm
+++ b/lib/PublicInbox/Import.pm
@@ -14,6 +14,7 @@ use PublicInbox::Address;
 use PublicInbox::MsgTime qw(msg_timestamp msg_datestamp);
 use PublicInbox::ContentId qw(content_digest);
 use PublicInbox::MDA;
+use POSIX qw(strftime);
 
 sub new {
        my ($class, $git, $name, $email, $ibx) = @_;
@@ -330,7 +331,7 @@ sub v1_mid0 ($) {
        my $mids = mids($hdr);
 
        if (!scalar(@$mids)) { # spam often has no Message-Id
-               my $mid0 = digest2mid(content_digest($mime));
+               my $mid0 = digest2mid(content_digest($mime), $hdr);
                append_mid($hdr, $mid0);
                return $mid0;
        }
@@ -445,18 +446,19 @@ sub atfork_child {
        }
 }
 
-sub digest2mid ($) {
-       my ($dig) = @_;
+sub digest2mid ($$) {
+       my ($dig, $hdr) = @_;
        my $b64 = $dig->clone->b64digest;
        # Make our own URLs nicer:
        # See "Base 64 Encoding with URL and Filename Safe Alphabet" in RFC4648
        $b64 =~ tr!+/=!-_!d;
 
-       # We can make this more meaningful with a date prefix or other things,
-       # but this is only needed for crap that fails to generate a Message-ID
-       # or reuses one.  In other words, it's usually spammers who hit this
-       # so they don't deserve nice Message-IDs :P
-       $b64 . '@localhost';
+       # Add a date prefix to prevent a leading '-' in case that trips
+       # up some tools (e.g. if a Message-ID were a expected as a
+       # command-line arg)
+       my $dt = msg_datestamp($hdr);
+       $dt = POSIX::strftime('%Y%m%d%H%M%S', gmtime($dt));
+       "$dt.$b64" . '@z';
 }
 
 sub clean_purge_buffer {