Ensure correct type parameter of serialized RemoteChannel

When serializing RemoteChannels, a new zeroed RemoteChannel is
constructed. However, the input type parameter might be part of an outer
type parameter which can then lead to a TypeError during deserialization.
The fix is just to reuse the type parameter of the input when
constructing the zeroed RemoteChannel.

Author: andreasnoack

src/remotecall.jl

@@ -413,8 +413,8 @@ function serialize(s::AbstractSerializer, ::Future)
     invoke(serialize, Tuple{AbstractSerializer, Any}, s, zero_fut)
 end
 
-function serialize(s::AbstractSerializer, ::RemoteChannel)
-    zero_rc = RemoteChannel{Channel{Any}}((0,0,0))
+function serialize(s::AbstractSerializer, ::RemoteChannel{T}) where T
+    zero_rc = RemoteChannel{T}((0,0,0))
     invoke(serialize, Tuple{AbstractSerializer, Any}, s, zero_rc)
 end
 

test/distributed_exec.jl

@@ -347,9 +347,9 @@ test_indexing(RemoteChannel(id_other))
 # Test ser/deser to non-ClusterSerializer objects.
 function test_regular_io_ser(ref::Distributed.AbstractRemoteRef)
     io = IOBuffer()
-    serialize(io, ref)
+    serialize(io, Dict("ref" => ref))
     seekstart(io)
-    ref2 = deserialize(io)
+    ref2 = deserialize(io)["ref"]
     for fld in fieldnames(typeof(ref))
         v = getfield(ref2, fld)
         if isa(v, Number)