[PATCH 2/2] aiaiai-email-lda: use the References mail header

[Jacob Keller]

From: Robert Jarzmik <robert.jarzmik at free.fr>

Aiaiai local mail delivery agent should be able to cope with forwarded
mails, not only git-send-email.

One popular method of forwarding a mail thread is to have it embedded in
a single mulitpart mail in rfc822 format. But this transformation
changes the In-Reply-To: headers into References: headers.

The goal of this patch is to teach aiaiai LDA to understand both
In-Reply-To and References in its mail handling. This enables mail
forwarding.

Jacob:
  Fix up variable quotes in the README example.
  Fix up style for mail headers, and fix a typo.

Signed-off-by: Robert Jarzmik <robert.jarzmik at free.fr>
Signed-off-by: Jacob Keller <jacob.e.keller at intel.com>
---
 doc/README             | 22 ++++++++++++++++++++++
 email/aiaiai-email-lda | 18 +++++++++++-------
 2 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/doc/README b/doc/README
index dbc25477bfda..9ec12540a79c 100644
--- a/doc/README
+++ b/doc/README
@@ -102,6 +102,28 @@ The 'aiaiai-test-patchset' script does all the testing work and outputs the
 test results to stdout. 'aiaiai-email-test-patchset' captures the output and
 sends it back to the patch submitter.
 
+A more complicated mail setup dealing with forwards and multi-part emails
+would be :
+$ cat /home/aiaiai/bin/my-aiaiai-lda
+	#!/bin/sh
+	formail_opt=""
+
+	mail=$(mktemp)
+	cat > $mail
+
+	to="$(formail -c -z -x "To:" < $mail)"
+	[ -n "$to" ] && formail_opt="$formail_opt -I \"To: $to\""
+
+	project="$(formail -c -z -x "X-Aiaiai-Project:" < $mail)"
+	[ -n "$project" ] && formail_opt="$formail_opt -I \"X-Aiaiai-Project: $project\""
+
+	commit="$(formail -c -z -x "X-Aiaiai-Commit:" < $mail)"
+	[ -n "$commit" ] && formail_opt="$formail_opt -I \"X-Aiaiai-Commit: $commit\""
+
+	cat "$mail" | eval formail $formail_opt -d -s "$HOME/git/email/aiaiai-email-lda" \
+	-v --reap-archive=43200 --reap-incomplete=10 -- "$HOME/aiaiai-workdir" \
+	>> "$HOME/aiaiai-logs/email-lda.log" 2>&1
+
 1.2 Email Configuration
 ~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/email/aiaiai-email-lda b/email/aiaiai-email-lda
index 365d7cfc60d2..4927dd194b2a 100755
--- a/email/aiaiai-email-lda
+++ b/email/aiaiai-email-lda
@@ -157,10 +157,10 @@ find_relatives()
 	local parent_id="$1"; shift
 
 	# Find the parent, children, and brothers
-	LC_ALL=C grep -i -l -r -- "In-Reply-To: $id" "$where" ||:
+	LC_ALL=C grep -i -l -r -- "\(In-Reply-To\|References\): $id" "$where" ||:
 	if [ -n "$parent_id" ]; then
 		LC_ALL=C grep -i -l -r -- "Message-Id: $parent_id" "$where" ||:
-		LC_ALL=C grep -i -l -r -- "In-Reply-To: $parent_id" "$where" ||:
+		LC_ALL=C grep -i -l -r -- "\(In-Reply-To\|References\): $parent_id" "$where" ||:
 	fi
 }
 
@@ -173,6 +173,7 @@ series_is_complete()
 	local cnt="$(ls -1 --ignore=0 -- "$dir" | wc -l)"
 	if [ "$cnt" -eq "$n" ]; then
 		local first_parent="$(fetch_header "In-Reply-To" < "$dir/1")"
+		[ -z "$first_parent" ] && first_parent="$(fetch_header "References" < "$dir/1")"
 		if [ -n "$first_parent" ]; then
 			# The first patch has a parent, must be the cover letter
 			if [ -f "$dir/0" ]; then
@@ -256,9 +257,9 @@ move_to_series()
 # try to collect all patches belonging to the series, and when it receives the
 # last patch, it queues the entire series.
 #
-# The series is collected using message ID headers - each patch, except of may
-# be the first one, must refer the previous patches ID via teh "In-Reply-To"
-# header.
+# The series is collected using message ID headers - each patch, except for the
+# first one, must refer the previous patches ID via the "In-Reply-To:" header
+# or "References:" header.
 process_series_mbox()
 {
 	local mbox="$1"; shift
@@ -269,12 +270,15 @@ process_series_mbox()
 
 	# Only patch 0/n or 1/n is allowed to have no parent
 	local parent_id="$(fetch_header "In-Reply-To" < "$mbox")"
+	[ -z "$parent_id" ] && parent_id="$(fetch_header "References" < "$mbox")"
+
 	if [ -z "$parent_id" ] && [ "$m" != 1 ] && [ "$m" != 0 ]; then
 		reject_and_reply "$mbox" <<EOF
 You sent a patch that does not conform to the requirements for Aiaiai's Local
 Delivery Agent. This patch is part of a series as indicated by its subject
-prefix.  However, it does not contain the correct "In-Reply-To:" header which
-is required for Aiaiai to determine which patch series it belongs with.
+prefix.  However, it does not contain the correct "In-Reply-To:" header or
+"References:" header which is required for Aiaiai to determine which patch
+series it belongs with.
 
 The most common reason for this issue is from not using the git-send-email
 utility, and using your own script which does not generate proper In-Reply-To:
-- 
2.1.2.555.gfbecd99