API: Refactor: Duplicate/free string arguments coming from msgpack

When receiving strings *from* msgpack, we don't need to duplicate/free since
the data only lives in the msgpack parse buffer until the end of the call.

But in order to reuse `msgpack_rpc_free_object` when sending event data(which is
sent *to* msgpack), Strings must be freed, which means they must also be
allocated separately.

1 files changed, 15 insertions, 2 deletions

diff --git a/src/nvim/os/msgpack_rpc.c b/src/nvim/os/msgpack_rpc.c
index d7ffa6f559..8ca1e0a8c0 100644
--- a/src/nvim/os/msgpack_rpc.c
+++ b/src/nvim/os/msgpack_rpc.c
@@ -147,9 +147,13 @@ bool msgpack_rpc_to_float(msgpack_object *obj, Float *arg)
 
 bool msgpack_rpc_to_string(msgpack_object *obj, String *arg)
 {
-  arg->data = (char *)obj->via.raw.ptr;
+  if (obj->type != MSGPACK_OBJECT_RAW) {
+    return false;
+  }
+
+  arg->data = xmemdup(obj->via.raw.ptr, obj->via.raw.size);
   arg->size = obj->via.raw.size;
-  return obj->type == MSGPACK_OBJECT_RAW;
+  return true;
 }
 
 bool msgpack_rpc_to_object(msgpack_object *obj, Object *arg)
@@ -328,6 +332,15 @@ void msgpack_rpc_from_dictionary(Dictionary result, msgpack_packer *res)
   }
 }
 
+void msgpack_rpc_free_string(String value)
+{
+  if (!value.data) {
+    return;
+  }
+
+  free(value.data);
+}
+
 void msgpack_rpc_free_object(Object value)
 {
   switch (value.type) {