1 files changed, 29 insertions, 18 deletions

diff --git a/src/nvim/os/channel.c b/src/nvim/os/channel.c
index 7cc40a67e0..a0575de2e9 100644
--- a/src/nvim/os/channel.c
+++ b/src/nvim/os/channel.c
@@ -207,12 +207,12 @@ static void parse_msgpack(RStream *rstream, void *data, bool eof)
   msgpack_unpacked unpacked;
   msgpack_unpacked_init(&unpacked);
   UnpackResult result;
-  msgpack_packer response;
 
   // Deserialize everything we can.
   while ((result = msgpack_rpc_unpack(channel->unpacker, &unpacked))
       == kUnpackResultOk) {
     // Each object is a new msgpack-rpc request and requires an empty response
+    msgpack_packer response;
     msgpack_packer_init(&response, channel->sbuffer, msgpack_sbuffer_write);
     // Perform the call
     msgpack_rpc_call(channel->id, &unpacked.data, &response);
@@ -234,24 +234,35 @@ static void parse_msgpack(RStream *rstream, void *data, bool eof)
     // A not so uncommon cause for this might be deserializing objects with
     // a high nesting level: msgpack will break when it's internal parse stack
     // size exceeds MSGPACK_EMBED_STACK_SIZE(defined as 32 by default)
-    msgpack_packer_init(&response, channel->sbuffer, msgpack_sbuffer_write);
-    msgpack_pack_array(&response, 4);
-    msgpack_pack_int(&response, 1);
-    msgpack_pack_int(&response, 0);
-    msgpack_rpc_error("Invalid msgpack payload. "
-                      "This error can also happen when deserializing "
-                      "an object with high level of nesting",
-                      &response);
-    WBuffer *buffer = wstream_new_buffer(xmemdup(channel->sbuffer->data,
-                                                 channel->sbuffer->size),
-                                         channel->sbuffer->size,
-                                         free);
-    if (!channel_write(channel, buffer)) {
-      return;
-    }
-    // Clear the buffer for future calls
-    msgpack_sbuffer_clear(channel->sbuffer);
+    send_error(channel, "Invalid msgpack payload. "
+                        "This error can also happen when deserializing "
+                        "an object with high level of nesting");
+  }
+}
+
+static void send_error(Channel *channel, char *msg)
+{
+  msgpack_packer err;
+  // See src/msgpack/unpack_template.h in msgpack source tree for
+  // causes for this error(search for 'goto _failed')
+  //
+  // A not so uncommon cause for this might be deserializing objects with
+  // a high nesting level: msgpack will break when it's internal parse stack
+  // size exceeds MSGPACK_EMBED_STACK_SIZE(defined as 32 by default)
+  msgpack_packer_init(&err, channel->sbuffer, msgpack_sbuffer_write);
+  msgpack_pack_array(&err, 4);
+  msgpack_pack_int(&err, 1);
+  msgpack_pack_int(&err, 0);
+  msgpack_rpc_error(msg, &err);
+  WBuffer *buffer = wstream_new_buffer(xmemdup(channel->sbuffer->data,
+                                               channel->sbuffer->size),
+                                       channel->sbuffer->size,
+                                       free);
+  if (!channel_write(channel, buffer)) {
+    return;
   }
+  // Clear the buffer for future calls
+  msgpack_sbuffer_clear(channel->sbuffer);
 }
 
 static bool channel_write(Channel *channel, WBuffer *buffer)