Allow DPR to be sent with diameter:call/4

DPR is sent by diameter at application shutdown, service stop, or
transport removal. It has been possible to send the request with
diameter:call/4, but the answer was discarded, instead of the transport
process being terminated. This commit causes DPR to be handled in the
same way regardless of whether it's sent by diameter or by
diameter:call/4.

Note that the behaviour subsequent to DPA is unchanged. In particular,
in the connecting case, the closed connection will be reestablished
after a connect_timer expiry unless the transport is removed. The more
probable use case is the listening case, to disconnect a single peer
associated with a listening transport.

1 files changed, 8 insertions, 6 deletions

diff --git a/lib/diameter/src/base/diameter_watchdog.erl b/lib/diameter/src/base/diameter_watchdog.erl
index b7f2d24941..6d7f6d7675 100644
--- a/lib/diameter/src/base/diameter_watchdog.erl
+++ b/lib/diameter/src/base/diameter_watchdog.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2010-2014. All Rights Reserved.
+%% Copyright Ericsson AB 2010-2015. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -332,8 +332,9 @@ transition({shutdown = T, Pid, Reason}, #watchdog{parent = Pid,
     send(TPid, {T, self(), Reason}),
     S#watchdog{shutdown = true};
 
-%% Transport is telling us that DPA has been sent in response to DPR:
-%% its death should lead to ours.
+%% Transport is telling us that DPA has been sent in response to DPR,
+%% or that DPR has been explicitly sent: transport death should lead
+%% to ours.
 transition({'DPR', TPid}, #watchdog{transport = TPid} = S) ->
     S#watchdog{shutdown = true};
 
@@ -549,7 +550,7 @@ send_watchdog(#watchdog{pending = false,
     ?LOG(send, 'DWR'),
     S#watchdog{pending = true}.
 
-%% Dont' count encode errors since we don't expect any on DWR/DWA.
+%% Don't count encode errors since we don't expect any on DWR/DWA.
 
 %% recv/3
 
@@ -590,9 +591,10 @@ rcv('DWA', Pkt, #watchdog{transport = TPid,
 rcv(N, _, _)
   when N == 'CER';
        N == 'CEA';
-       N == 'DPR';
-       N == 'DPA' ->
+       N == 'DPR' ->
     false;
+%% DPR can be sent explicitly with diameter:call/4. Only the
+%% corresponding DPAs arrive here.
 
 rcv(_, Pkt, #watchdog{transport = TPid,
                       dictionary = Dict0,