Cutthrough: Fix bug with dot-only line

(cherry picked from commit 1bc460a64a0de0766d21f4f8660c6597bc410cbc)

Conflicts:
	doc/doc-txt/ChangeLog
	test/log/5400
	test/scripts/5400-cutthrough/5400
	test/stdout/5400

5 files changed, 223 insertions, 124 deletions

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 38a5f5a65..86b615eef 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -6,6 +6,14 @@ Exim version 4.84+fixes
 Cherry-Picked from the master development branch
 for complaints please contact hs@schlittermann.de
 -------------------------------------------------
+JH/38 Fix cutthrough bug with body lines having a single dot. The dot was
+      incorrectly not doubled on cutthrough transmission, hence seen as a
+      body-termination at the receiving system - resulting in truncated mails.
+      Commonly the sender saw a TCP-level error, and retransmitted the nessage
+      via the normal store-and-forward channel. This could result in duplicates
+      received - but deduplicating mailstores were liable to retain only the
+      initial truncated version.
+
 
 JH/05 Fix results-pipe from transport process.  Several recipients, combined
       with certificate use, exposed issues where response data items split
diff --git a/src/src/receive.c b/src/src/receive.c
index f27dc425e..b6c1d4e41 100644
--- a/src/src/receive.c
+++ b/src/src/receive.c
@@ -838,7 +838,15 @@ while ((ch = (receive_getc)()) != EOF)
       ch_state = 4;
       continue;
       }
-    ch_state = 1;                       /* The dot itself is removed */
+    /* The dot was removed at state 3. For a doubled dot, here, reinstate
+    it to cutthrough. The current ch, dot or not, is passed both to cutthrough
+    and to file below. */
+    if (ch == '.')
+      {
+      uschar c= ch;
+      (void) cutthrough_puts(&c, 1);
+      }
+    ch_state = 1;
     break;
 
     case 4:                             /* After [CR] LF . CR */
diff --git a/test/log/5400 b/test/log/5400
index 6b51348c3..2e05c2547 100644
--- a/test/log/5400
+++ b/test/log/5400
@@ -16,3 +16,7 @@
 1999-03-02 09:44:33 10HmbA-0005vi-00 >> userx@domain.com R=all T=smtp H=127.0.0.1 [127.0.0.1] C="250 OK"
 1999-03-02 09:44:33 10HmbA-0005vi-00 <= CALLER@myhost.test.ex U=CALLER P=local-esmtp S=sss
 1999-03-02 09:44:33 10HmbA-0005vi-00 Completed
+1999-03-02 09:44:33 rcpt for userx@domain.com
+1999-03-02 09:44:33 10HmbH-0005vi-00 >> userx@domain.com R=all T=smtp H=127.0.0.1 [127.0.0.1] C="250 OK"
+1999-03-02 09:44:33 10HmbH-0005vi-00 <= CALLER@myhost.test.ex U=CALLER P=local-esmtp S=sss for userx@domain.com
+1999-03-02 09:44:33 10HmbH-0005vi-00 Completed
diff --git a/test/scripts/5400-cutthrough/5400 b/test/scripts/5400-cutthrough/5400
index 3e56b43b8..501113ca8 100644
--- a/test/scripts/5400-cutthrough/5400
+++ b/test/scripts/5400-cutthrough/5400
@@ -123,3 +123,37 @@ body
 .
 QUIT
 ****
+# data having line with (logical, doubled on wire) single dot
+server PORT_S
+220 ESMTP
+EHLO
+250 OK
+MAIL FROM:
+250 Sender OK
+RCPT TO:
+250 Recipient OK
+DATA
+354 Send data
+.
+250 OK
+QUIT
+250 OK
+****
+exim -bs -odf
+EHLO myhost.test.ex
+MAIL FROM:<CALLER@myhost.test.ex>
+RCPT TO:<userx@domain.com>
+DATA
+Subject: singledot test
+
+This data has a line with a single dot... next:
+..
+and this is the line right after.
+Next we have a line with a leading dot:
+..test
+and this is the next line.
+
+.
+QUIT
+****
+#
diff --git a/test/stdout/5400 b/test/stdout/5400
index 4895072a3..e0aa25fc1 100644
--- a/test/stdout/5400
+++ b/test/stdout/5400
@@ -43,126 +43,171 @@
 354 Enter message, ending with "." on a line by itself

 250 OK id=10HmbA-0005vi-00

 221 myhost.test.ex closing connection

-
-******** SERVER ********
-Listening on port 1224 ... 
-Connection request from [ip4.ip4.ip4.ip4]
-220 ESMTP
-EHLO myhost.test.ex
-250 OK
-MAIL FROM:<CALLER@myhost.test.ex>
-250 Sender OK
-RCPT TO:<userx@domain.com>
-250 Recipient OK
-DATA
-354 Send data
-Received: from CALLER (helo=myhost.test.ex)
-	by myhost.test.ex with local-esmtp (Exim x.yz)
-	(envelope-from <CALLER@myhost.test.ex>)
-	id 10HmaX-0005vi-00
-	for userx@domain.com; Tue, 2 Mar 1999 09:44:33 +0000
-Message-Id: <E10HmaX-0005vi-00@myhost.test.ex>
-From: CALLER_NAME <CALLER@myhost.test.ex>
-Date: Tue, 2 Mar 1999 09:44:33 +0000
-X-hdr-rtr-new: +++
-
-.
-250 OK
-QUIT
-250 OK
-End of script
-Listening on port 1224 ... 
-Connection request from [ip4.ip4.ip4.ip4]
-220 SMTP only spoken here
-EHLO myhost.test.ex
-550 Not here, mate
-HELO myhost.test.ex
-250 OK
-MAIL FROM:<CALLER@myhost.test.ex>
-250 Sender OK
-RCPT TO:<userz@domain.com>
-250 Recipient OK
-DATA
-354 Send data
-Received: from CALLER (helo=myhost.test.ex)
-	by myhost.test.ex with local-esmtp (Exim x.yz)
-	(envelope-from <CALLER@myhost.test.ex>)
-	id 10HmaY-0005vi-00
-	for userz@domain.com; Tue, 2 Mar 1999 09:44:33 +0000
-Message-Id: <E10HmaY-0005vi-00@myhost.test.ex>
-From: CALLER_NAME <CALLER@myhost.test.ex>
-Date: Tue, 2 Mar 1999 09:44:33 +0000
-X-hdr-rtr-new: +++
-
-.
-250 OK
-QUIT
-250 OK
-End of script
-Listening on port 1224 ... 
-Connection request from [ip4.ip4.ip4.ip4]
-220 ESMTP
-EHLO myhost.test.ex
-250 OK
-MAIL FROM:<CALLER@myhost.test.ex>
-250 Sender OK
-RCPT TO:<usery@domain.com>
-250 Recipient OK
-QUIT
-Expected EOF read from client
-Listening on port 1224 ... 
-Connection request from [ip4.ip4.ip4.ip4]
-220 ESMTP
-EHLO myhost.test.ex
-250 OK
-MAIL FROM:<CALLER@myhost.test.ex>
-250 Sender OK
-RCPT TO:<usery@domain.com>
-250 Recipient OK
-RCPT TO:<userx@domain.com>
-250 Recipient OK
-DATA
-354 Send data
-Received: from CALLER (helo=myhost.test.ex)
-	by myhost.test.ex with local-esmtp (Exim x.yz)
-	(envelope-from <CALLER@myhost.test.ex>)
-	id 10HmaZ-0005vi-00; Tue, 2 Mar 1999 09:44:33 +0000
-Message-Id: <E10HmaZ-0005vi-00@myhost.test.ex>
-From: CALLER_NAME <CALLER@myhost.test.ex>
-Date: Tue, 2 Mar 1999 09:44:33 +0000
-X-hdr-rtr-new: +++
-
-.
-250 OK
-QUIT
-250 OK
-End of script
-Listening on port 1224 ... 
-Connection request from [ip4.ip4.ip4.ip4]
-220 ESMTP
-EHLO myhost.test.ex
-250 OK
-MAIL FROM:<CALLER@myhost.test.ex>
-250 Sender OK
-RCPT TO:<userx@domain.com>
-250 Recipient OK
-DATA
-354 Send data
-Received: from CALLER (helo=myhost.test.ex)
-	by myhost.test.ex with local-esmtp (Exim x.yz)
-	(envelope-from <CALLER@myhost.test.ex>)
-	id 10HmbA-0005vi-00
-	for userx@domain.com; Tue, 2 Mar 1999 09:44:33 +0000
-X-hdr-tpt: zzz
-Message-Id: <E10HmbA-0005vi-00@myhost.test.ex>
-From: CALLER_NAME <CALLER@myhost.test.ex>
-Date: Tue, 2 Mar 1999 09:44:33 +0000
-X-hdr-rtr-new: +++
-
-
-body
-.
-250 OK
-QUIT
-250 OK
-End of script
+220 myhost.test.ex ESMTP Exim x.yz Tue, 2 Mar 1999 09:44:33 +0000

+250-myhost.test.ex Hello CALLER at myhost.test.ex

+250-SIZE 52428800

+250-8BITMIME

+250-PIPELINING

+250 HELP

+250 OK

+250 Accepted

+354 Enter message, ending with "." on a line by itself

+250 OK id=10HmbH-0005vi-00

+221 myhost.test.ex closing connection

+

+******** SERVER ********

+Listening on port 1224 ... 

+Connection request from [ip4.ip4.ip4.ip4]

+220 ESMTP

+EHLO myhost.test.ex

+250 OK

+MAIL FROM:<CALLER@myhost.test.ex>

+250 Sender OK

+RCPT TO:<userx@domain.com>

+250 Recipient OK

+DATA

+354 Send data

+Received: from CALLER (helo=myhost.test.ex)

+	by myhost.test.ex with local-esmtp (Exim x.yz)

+	(envelope-from <CALLER@myhost.test.ex>)

+	id 10HmaX-0005vi-00

+	for userx@domain.com; Tue, 2 Mar 1999 09:44:33 +0000

+Message-Id: <E10HmaX-0005vi-00@myhost.test.ex>

+From: CALLER_NAME <CALLER@myhost.test.ex>

+Date: Tue, 2 Mar 1999 09:44:33 +0000

+X-hdr-rtr-new: +++

+

+.

+250 OK

+QUIT

+250 OK

+End of script

+Listening on port 1224 ... 

+Connection request from [ip4.ip4.ip4.ip4]

+220 SMTP only spoken here

+EHLO myhost.test.ex

+550 Not here, mate

+HELO myhost.test.ex

+250 OK

+MAIL FROM:<CALLER@myhost.test.ex>

+250 Sender OK

+RCPT TO:<userz@domain.com>

+250 Recipient OK

+DATA

+354 Send data

+Received: from CALLER (helo=myhost.test.ex)

+	by myhost.test.ex with local-esmtp (Exim x.yz)

+	(envelope-from <CALLER@myhost.test.ex>)

+	id 10HmaY-0005vi-00

+	for userz@domain.com; Tue, 2 Mar 1999 09:44:33 +0000

+Message-Id: <E10HmaY-0005vi-00@myhost.test.ex>

+From: CALLER_NAME <CALLER@myhost.test.ex>

+Date: Tue, 2 Mar 1999 09:44:33 +0000

+X-hdr-rtr-new: +++

+

+.

+250 OK

+QUIT

+250 OK

+End of script

+Listening on port 1224 ... 

+Connection request from [ip4.ip4.ip4.ip4]

+220 ESMTP

+EHLO myhost.test.ex

+250 OK

+MAIL FROM:<CALLER@myhost.test.ex>

+250 Sender OK

+RCPT TO:<usery@domain.com>

+250 Recipient OK

+QUIT

+Expected EOF read from client

+Listening on port 1224 ... 

+Connection request from [ip4.ip4.ip4.ip4]

+220 ESMTP

+EHLO myhost.test.ex

+250 OK

+MAIL FROM:<CALLER@myhost.test.ex>

+250 Sender OK

+RCPT TO:<usery@domain.com>

+250 Recipient OK

+RCPT TO:<userx@domain.com>

+250 Recipient OK

+DATA

+354 Send data

+Received: from CALLER (helo=myhost.test.ex)

+	by myhost.test.ex with local-esmtp (Exim x.yz)

+	(envelope-from <CALLER@myhost.test.ex>)

+	id 10HmaZ-0005vi-00; Tue, 2 Mar 1999 09:44:33 +0000

+Message-Id: <E10HmaZ-0005vi-00@myhost.test.ex>

+From: CALLER_NAME <CALLER@myhost.test.ex>

+Date: Tue, 2 Mar 1999 09:44:33 +0000

+X-hdr-rtr-new: +++

+

+.

+250 OK

+QUIT

+250 OK

+End of script

+Listening on port 1224 ... 

+Connection request from [ip4.ip4.ip4.ip4]

+220 ESMTP

+EHLO myhost.test.ex

+250 OK

+MAIL FROM:<CALLER@myhost.test.ex>

+250 Sender OK

+RCPT TO:<userx@domain.com>

+250 Recipient OK

+DATA

+354 Send data

+Received: from CALLER (helo=myhost.test.ex)

+	by myhost.test.ex with local-esmtp (Exim x.yz)

+	(envelope-from <CALLER@myhost.test.ex>)

+	id 10HmbA-0005vi-00

+	for userx@domain.com; Tue, 2 Mar 1999 09:44:33 +0000

+X-hdr-tpt: zzz

+Message-Id: <E10HmbA-0005vi-00@myhost.test.ex>

+From: CALLER_NAME <CALLER@myhost.test.ex>

+Date: Tue, 2 Mar 1999 09:44:33 +0000

+X-hdr-rtr-new: +++

+

+

+.

+250 OK

+QUIT

+250 OK

+End of script

+Listening on port 1224 ... 

+Connection request from [ip4.ip4.ip4.ip4]

+220 ESMTP

+EHLO myhost.test.ex

+250 OK

+MAIL FROM:<CALLER@myhost.test.ex>

+250 Sender OK

+RCPT TO:<userx@domain.com>

+250 Recipient OK

+DATA

+354 Send data

+Received: from CALLER (helo=myhost.test.ex)

+	by myhost.test.ex with local-esmtp (Exim x.yz)

+	(envelope-from <CALLER@myhost.test.ex>)

+	id 10HmbH-0005vi-00

+	for userx@domain.com; Tue, 2 Mar 1999 09:44:33 +0000

+Subject: singledot test

+Message-Id: <E10HmbH-0005vi-00@myhost.test.ex>

+From: CALLER_NAME <CALLER@myhost.test.ex>

+Date: Tue, 2 Mar 1999 09:44:33 +0000

+X-hdr-rtr-new: +++

+

+This data has a line with a single dot... next:

+..

+and this is the line right after.

+Next we have a line with a leading dot:

+..test

+and this is the next line.

+

+body

+.

+250 OK

+QUIT

+250 OK

+End of script