4 files changed, 69 insertions, 38 deletions
diff --git a/lib/diameter/doc/src/diameter.xml b/lib/diameter/doc/src/diameter.xml
index 36b6cbf0cf..2cad70e3bc 100644
--- a/lib/diameter/doc/src/diameter.xml
+++ b/lib/diameter/doc/src/diameter.xml
@@ -277,6 +277,10 @@ callback.</p>
 
 </taglist>
 
+<p>
+An invalid option will cause <seealso marker="#call">call/4</seealso>
+to fail.</p>
+
 <marker id="capability"/>
 </item>
 
@@ -405,6 +409,8 @@ sense.</p>
 <code>
 eval([{M,F,A} | T]) ->
     apply(M, F, T ++ A);
+eval([[F|A] | T]) ->
+    eval([F | T ++ A]);
 eval([F|A]) ->
     apply(F, A);
 eval(F) ->
@@ -461,14 +467,14 @@ or any peer if the request does not contain
 a <c>Destination-Realm</c> AVP.</p>
 </item>
 
-<tag><c>{host, any|UTF8String()}</c></tag>
+<tag><c>{host, any|DiameterIdentity()}</c></tag>
 <item>
 <p>
 Matches only those peers whose <c>Origin-Host</c> has the
 specified value, or all peers if the atom <c>any</c>.</p>
 </item>
 
-<tag><c>{realm, any|UTF8String()</c></tag>
+<tag><c>{realm, any|DiameterIdentity()</c></tag>
 <item>
 <p>
 Matches only those peers whose <c>Origin-Realm</c> has the
@@ -478,8 +484,9 @@ value, or all peers if the atom <c>any</c>.</p>
 <tag><c>{eval, evaluable()}</c></tag>
 <item>
 <p>
-Matches only those peers for which the specified evaluable() evaluates
-to true on the peer's <c>diameter_caps</c> record.</p>
+Matches only those peers for which the specified evaluable() returns
+<c>true</c> on the connection's <c>diameter_caps</c> record.
+Any other return value or exception is equivalent to <c>false</c>.</p>
 </item>
 
 <tag><c>{neg, peer_filter()}</c></tag>
@@ -503,6 +510,21 @@ specified list.</p>
 
 </taglist>
 
+<p>
+Note that the <c>host</c> and <c>realm</c> filters examine the
+outgoing request as passed to <seealso marker="#call">call/4</seealso>,
+assuming that this is a record- or list-valued message() as documented
+in <seealso marker="diameter_app">diameter_app(3)</seealso>, and that
+the message contains at most one of each AVP.
+If this is not the case then the <c>{host|realm, DiameterIdentity()}</c>
+filters must be used to achieve the desired result.
+Note also that an empty host/realm (which should not be typical)
+is equivalent to an unspecified one for the purposes of filtering.</p>
+
+<p>
+An invalid filter is equivalent to <c>{any, []}</c>, a filter
+that matches no peer.</p>
+
 <marker id="service_event"/>
 </item>
 
@@ -787,7 +809,7 @@ transports.</p>
 <type>
 <v>SvcName = service_name()</v>
 <v>App = application_alias()</v>
-<v>Request = diameter_app:message()</v>
+<v>Request = diameter_app:message() | term()</v>
 <v>Answer = term()</v>
 <v>Options = [call_opt()]</v>
 </type>
@@ -819,9 +841,8 @@ If there are no suitable peers, or if
 <seealso marker="diameter_app#pick_peer">pick_peer/4</seealso>
 rejects them by returning 'false', then <c>{error, no_connection}</c>
 is returned.
-If <seealso marker="diameter_app#pick_peer">pick_peer/4</seealso>
-selects a candidate peer then a request process is spawned for the
-outgoing request, in which there is a
+Otherwise <seealso marker="diameter_app#pick_peer">pick_peer/4</seealso>
+is followed by a
 <seealso
 marker="diameter_app#prepare_request">prepare_request/3</seealso>
 callback, the message is encoded and sent.</p>
diff --git a/lib/diameter/doc/src/diameter_app.xml b/lib/diameter/doc/src/diameter_app.xml
index fc359b9d1d..a9ae0ebbec 100644
--- a/lib/diameter/doc/src/diameter_app.xml
+++ b/lib/diameter/doc/src/diameter_app.xml
@@ -269,7 +269,12 @@ The candidate peers list will only include those
 which are selected by any <c>filter</c> option specified in the call to
 <seealso marker="diameter#call">diameter:call/4</seealso>, and only
 those which have indicated support for the Diameter application in
-question.</p>
+question.
+The order of the elements is unspecified except that any
+peers whose Origin-Host and Origin-Realm matches that of the
+outgoing request (in the sense of a <c>{filter, {all, [host, realm]}}</c>
+option to <seealso marker="diameter#call">diameter:call/4</seealso>)
+will be placed at the head of the list.</p>
 
 <p>
 The return values <c>false</c> and <c>{false, State}</c> are
@@ -467,11 +472,11 @@ callback returned false.</p>
 <v>Packet  = packet()</v>
 <v>SvcName = term()</v>
 <v>Peer    = peer()</v>
-<v>Action  = Reply | {relay, Opts} | discard | {eval, Action, ContF}</v>
+<v>Action  = Reply | {relay, Opts} | discard | {eval, Action, PostF}</v>
 <v>Reply   = {reply, message()}
            | {protocol_error, 3000..3999}</v>
 <v>Opts    = diameter:call_opts()</v>
-<v>ContF   = diameter:evaluable()</v>
+<v>PostF   = diameter:evaluable()</v>
 </type>
 <desc>
 <p>
@@ -559,26 +564,28 @@ will cause the request process in question to fail.</p>
 <tag><c>{relay, Opts}</c></tag>
 <item>
 <p>
-Relay a request to another peer.
-The appropriate Route-Record AVP will be added to the relayed request
-by diameter and <seealso marker="#pick_peer">pick_peer/4</seealso>
-and <seealso marker="#prepare_request">prepare_request/3</seealso>
-callback will take place just as if <seealso
+Relay a request to another peer in the role of a Diameter relay agent.
+If a routing loop is detected then the request is answered with
+3005 (DIAMETER_LOOP_DETECTED).
+Otherwise a Route-Record AVP (containing the sending peer's Origin-Host) is
+added to the request and <seealso marker="#pick_peer">pick_peer/4</seealso>
+and subsequent callbacks take place just as if <seealso
 marker="diameter#call">diameter:call/4</seealso> had been called
 explicitly.
-However, returning a <c>relay</c> tuple also causes the End-to-End
-Identifier to be preserved in the header of the relayed request as
-required by RFC 3588.</p>
+The End-to-End Identifier of the incoming request is preserved in the
+header of the relayed request.</p>
 
 <p>
-The returned <c>Opts</c> should not specify <c>detach</c> and
-the <seealso marker="#handle_answer">handle_answer/4</seealso>
-callback following from a relayed request must return its first
+The returned <c>Opts</c> should not specify <c>detach</c>.
+A subsequent <seealso marker="#handle_answer">handle_answer/4</seealso>
+callback for the relayed request must return its first
 argument, the <c>diameter_packet</c> record containing the answer
 message.
 Note that the <c>extra</c> option can be specified to supply arguments
-that can distinguish the relay case from others if so desired,
-although the form of the request message may be sufficient.</p>
+that can distinguish the relay case from others if so desired.
+Any other return value (for example, from a
+<seealso marker="#handle_error">handle_error/4</seealso> callback)
+causes the request to be answered with 3002 (DIAMETER_UNABLE_TO_DELIVER).</p>
 </item>
 
 <tag><c>discard</c></tag>
@@ -587,18 +594,18 @@ although the form of the request message may be sufficient.</p>
 Discard the request.</p>
 </item>
 
-<tag><c>{eval, Action, ContF}</c></tag>
+<tag><c>{eval, Action, PostF}</c></tag>
 <item>
 <p>
 Handle the request as if <c>Action</c> has been returned and then
-evaluate <c>ContF</c> in the request process.</p>
+evaluate <c>PostF</c> in the request process.</p>
 </item>
 
 </taglist>
 
 <p>
-Note that diameter will respond to protocol errors in an incoming
-request without invoking <c>handle_request/3</c>.</p>
+Note that protocol errors detected by diameter will result in an
+answer message without <c>handle_request/3</c> being invoked.</p>
 
 </desc>
 </func>
diff --git a/lib/diameter/doc/src/diameter_sctp.xml b/lib/diameter/doc/src/diameter_sctp.xml
index d0377f4b38..c1e839b8e1 100644
--- a/lib/diameter/doc/src/diameter_sctp.xml
+++ b/lib/diameter/doc/src/diameter_sctp.xml
@@ -74,11 +74,12 @@ marker="diameter_transport#start">diameter_transport(3)</seealso>.</p>
 <p>
 The only diameter_sctp-specific argument is the options list.
 Options <c>raddr</c> and <c>rport</c> specify the remote address
-and port for a connector and not valid for a listener.
+and port for a connecting transport and not valid for a listening
+transport.
 The former is required while latter defaults to 3868 if unspecified.
 More than one <c>raddr</c> option can be specified, in which case the
-connector in question attempts each in sequence until an association
-is established.
+connecting transport in question attempts each in sequence until
+an association is established.
 Remaining options are any accepted by gen_sctp:open/1, with the exception
 of options <c>mode</c>, <c>binary</c>, <c>list</c>, <c>active</c>
 and <c>sctp_events</c>.
@@ -89,7 +90,8 @@ and port respectively.</p>
 Multiple <c>ip</c> options can be specified for a multihomed peer.
 If none are specified then the values of Host-IP-Address
 on the service are used. (In particular, one of these must be specified.)
-Option <c>port</c> defaults to 3868 for a listener and 0 for a connector.</p>
+Option <c>port</c> defaults to 3868 for a listening transport and 0 for a
+connecting transport.</p>
 
 <p>
 diameter_sctp uses the <c>transport_data</c> field of
diff --git a/lib/diameter/doc/src/diameter_tcp.xml b/lib/diameter/doc/src/diameter_tcp.xml
index 5d6e07b1b8..a502e53972 100644
--- a/lib/diameter/doc/src/diameter_tcp.xml
+++ b/lib/diameter/doc/src/diameter_tcp.xml
@@ -74,13 +74,14 @@ marker="diameter_transport#start">diameter_transport(3)</seealso>.</p>
 <p>
 The only diameter_tcp-specific argument is the options list.
 Options <c>raddr</c> and <c>rport</c> specify the remote address
-and port for a connector and not valid for a listener.
+and port for a connecting transport and not valid for a listening
+transport.
 Remaining options are any accepted by gen_tcp:connect/3 for
-a connector, or gen_tcp:listen/2 for a listener, with the exception
-of <c>binary</c>, <c>packet</c> and <c>active</c>.
-Also, option <c>port</c> can be specified for a listener to specify the
-local listening port, the default being the standardized 3868 if
-unspecified.
+a connecting transport, or gen_tcp:listen/2 for a listening transport,
+with the exception of <c>binary</c>, <c>packet</c> and <c>active</c>.
+Also, option <c>port</c> can be specified for a listening transport
+to specify the local listening port, the default being the standardized
+3868 if unspecified.
 Note that option <c>ip</c> specifies the local address.</p>
 
 <p>