Strip leading/trailing newlines on list of headers for addition; bug 884.

NB: this means a bare "X-ACL-Warn:" header is harder to add.

5 files changed, 17 insertions, 4 deletions

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index d35c305c8..5961c4bd4 100644
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -27320,7 +27320,9 @@ receiving a message). The message must ultimately be accepted for
 any ACL verb, including &%deny%& (though this is potentially useful only in a
 RCPT ACL).
 
-If the data for the &%add_header%& modifier contains one or more newlines that
+Leading and trailing newlines are removed from
+the data for the &%add_header%& modifier; if it then
+contains one or more newlines that
 are not followed by a space or a tab, it is assumed to contain multiple header
 lines. Each one is checked for valid syntax; &`X-ACL-Warn:`& is added to the
 front of any line that is not a valid header line.
diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index a4c10d13a..6e91c1070 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -71,6 +71,9 @@ JH/06 Add dnsdb pseudo-lookup "a+" to do an "aaaa" + "a" combination.
 JH/07 Avoid using a waiting database for a single-message-only transport.
       Performance patch from Paul Fisher.  Bugzilla 1262.
 
+JH/08 Strip leading/trailing newlines from add_header ACL modifier data.
+      Bugzilla 884.
+
 
 Exim version 4.80
 -----------------
diff --git a/src/src/acl.c b/src/src/acl.c
index 3b23a915b..f9a32d3b7 100644
--- a/src/src/acl.c
+++ b/src/src/acl.c
@@ -958,10 +958,13 @@ setup_header(uschar *hstring)
 uschar *p, *q;
 int hlen = Ustrlen(hstring);
 
-/* An empty string does nothing; otherwise add a final newline if necessary. */
+/* Ignore any leading newlines */
+while (*hstring == '\n') hstring++, hlen--;
 
+/* An empty string does nothing; ensure exactly one final newline. */
 if (hlen <= 0) return;
-if (hstring[hlen-1] != '\n') hstring = string_sprintf("%s\n", hstring);
+if (hstring[--hlen] != '\n') hstring = string_sprintf("%s\n", hstring);
+else while(hstring[--hlen] == '\n') hstring[hlen+1] = '\0';
 
 /* Loop for multiple header lines, taking care about continuations */
 
diff --git a/test/confs/0496 b/test/confs/0496
index 4bc2fde19..89375b11d 100644
--- a/test/confs/0496
+++ b/test/confs/0496
@@ -19,10 +19,12 @@ acl_smtp_rcpt = check_rcpt
 begin acl
 
 check_rcpt:
-  warn     message = data1 data1\ndata2 data2
+  warn     message = data1 data1\ndata2 data2\n
+  warn     message = \n\ndata3\n\ndata4\n\n
   warn     message = :after_received:After-Received: some text\n\
                      :at_start:At-Start: some text\n\
                      :at_end:  At-End: some text
+  warn     message = data4
   accept
 
 
diff --git a/test/mail/0496.someone b/test/mail/0496.someone
index 49cda3694..263f59686 100644
--- a/test/mail/0496.someone
+++ b/test/mail/0496.someone
@@ -12,6 +12,9 @@ Sender: CALLER_NAME <CALLER@myhost.test.ex>
 Date: Tue, 2 Mar 1999 09:44:33 +0000
 X-ACL-Warn: data1 data1
 X-ACL-Warn: data2 data2
+X-ACL-Warn: data3
+X-ACL-Warn: 
+X-ACL-Warn: data4
 At-End: some text
 
 Testing message