From 5d74333219454f9794cd4116241cd2ec98df4934 Mon Sep 17 00:00:00 2001
From: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Date: Mon, 18 Nov 2013 22:14:36 -0800
Subject: [PATCH] protobuf-c-rpc/protobuf-c-rpc.c: handle server responses with
 NULL messages on the client side (fixes #78)

protobuf-c-rpc/t/test-rpc.c: add a test case for #78
---
 protobuf-c-rpc/protobuf-c-rpc.c | 48 ++++++++++++++++++++-------------
 protobuf-c-rpc/t/test-rpc.c     |  9 +++++++
 2 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/protobuf-c-rpc/protobuf-c-rpc.c b/protobuf-c-rpc/protobuf-c-rpc.c
index 09b40cc..fc1b147 100644
--- a/protobuf-c-rpc/protobuf-c-rpc.c
+++ b/protobuf-c-rpc/protobuf-c-rpc.c
@@ -562,7 +562,6 @@ handle_client_fd_events (int                fd,
               uint32_t header[4];
               unsigned status_code, method_index, message_length, request_id;
               Closure *closure;
-              uint8_t *packed_data;
               ProtobufCMessage *msg;
               protobuf_c_data_buffer_peek (&client->incoming, header, sizeof (header));
               status_code = uint32_from_le (header[0]);
@@ -583,23 +582,36 @@ handle_client_fd_events (int                fd,
                 }
               closure = client->info.connected.closures + (request_id - 1);
 
-              /* read message and unpack */
+              /* Discard the RPC header */
               protobuf_c_data_buffer_discard (&client->incoming, 16);
-              packed_data = client->allocator->alloc (client->allocator, message_length);
-              protobuf_c_data_buffer_read (&client->incoming, packed_data, message_length);
 
-              /* TODO: use fast temporary allocator */
-              msg = protobuf_c_message_unpack (closure->response_type,
-                                               client->allocator,
-                                               message_length,
-                                               packed_data);
-              if (msg == NULL)
-                {
-                  fprintf(stderr, "unable to unpack msg of length %u", message_length);
-                  client_failed (client, "failed to unpack message");
-                  client->allocator->free (client->allocator, packed_data);
-                  return;
-                }
+              if (status_code == PROTOBUF_C_STATUS_CODE_SUCCESS)
+              {
+                 /* read message and unpack */
+                 uint8_t *packed_data =
+                    client->allocator->alloc (client->allocator, message_length);
+                 protobuf_c_data_buffer_read (&client->incoming, packed_data, message_length);
+
+                 /* TODO: use fast temporary allocator */
+                 msg = protobuf_c_message_unpack (closure->response_type,
+                       client->allocator,
+                       message_length,
+                       packed_data);
+
+                 client->allocator->free (client->allocator, packed_data);
+                 if (msg == NULL)
+                 {
+                    fprintf(stderr, "unable to unpack msg of length %u", message_length);
+                    client_failed (client, "failed to unpack message");
+                    return;
+                 }
+              }
+              else
+              {
+                 /* Server did not send a response message */
+                 protobuf_c_assert (message_length == 0);
+                 msg = NULL;
+              }
 
               /* invoke closure */
               closure->closure (msg, closure->closure_data);
@@ -609,8 +621,8 @@ handle_client_fd_events (int                fd,
               client->info.connected.first_free_request_id = request_id;
 
               /* clean up */
-              protobuf_c_message_free_unpacked (msg, client->allocator);
-              client->allocator->free (client->allocator, packed_data);
+              if (msg)
+                 protobuf_c_message_free_unpacked (msg, client->allocator);
             }
         }
     }
diff --git a/protobuf-c-rpc/t/test-rpc.c b/protobuf-c-rpc/t/test-rpc.c
index 2bccfd3..2a186d7 100644
--- a/protobuf-c-rpc/t/test-rpc.c
+++ b/protobuf-c-rpc/t/test-rpc.c
@@ -33,7 +33,10 @@ test__by_name (Foo__DirLookup_Service *service,
   char *email = NULL;
   (void) service;
   if (name->name == NULL)
+  {
     closure (NULL, closure_data);
+    return;
+  }
   else if (strcmp (name->name, "dave") == 0)
     {
       number = "555-1212";
@@ -130,6 +133,12 @@ test_service (ProtobufCService *service)
   foo__dir_lookup__by_name (service, &name, test_not_found_closure, &is_done);
   while (!is_done)
     protobuf_c_dispatch_run (protobuf_c_dispatch_default ());
+
+  name.name = NULL;
+  is_done = 0;
+  foo__dir_lookup__by_name (service, &name, test_defunct_closure, &is_done);
+  while (!is_done)
+    protobuf_c_dispatch_run (protobuf_c_dispatch_default ());
 }
 static void
 test_defunct_client (ProtobufCService *service)