From 54f318f413d0fdf8a9d488a19c66b85697312ca0 Mon Sep 17 00:00:00 2001
From: "Eric Wong (Contractor, The Linux Foundation)" <e@80x24.org>
Date: Mon, 19 Mar 2018 08:14:47 +0000
Subject: import: switch to URL-safe Base64 for Message-IDs

Hexdigests are too long and shorter Message-IDs are easier
to deal with.
---
 lib/PublicInbox/Import.pm | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

(limited to 'lib/PublicInbox/Import.pm')

diff --git a/lib/PublicInbox/Import.pm b/lib/PublicInbox/Import.pm
index 4c007b61..77e74c13 100644
--- a/lib/PublicInbox/Import.pm
+++ b/lib/PublicInbox/Import.pm
@@ -401,7 +401,16 @@ sub atfork_child {
 
 sub digest2mid ($) {
 	my ($dig) = @_;
-	$dig->clone->hexdigest . '@localhost';
+	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';
 }
 
 1;
-- 
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