Allow storing unknown enum values (#209)

Author: Drvi

src/codec/decode.jl

@@ -26,7 +26,7 @@ end
 decode(d::AbstractProtoDecoder, ::Type{Bool}) = Bool(read(d.io, UInt8))
 function decode(d::AbstractProtoDecoder, ::Type{T}) where {T <: Union{Enum{Int32},Enum{UInt32}}}
     val = vbyte_decode(d.io, UInt32)
-    return val in keys(Base.Enums.namemap(T)) ? T(val) : T(0)
+    return Core.bitcast(T, reinterpret(Int32, val))
 end
 decode(d::AbstractProtoDecoder, ::Type{T}) where {T <: Union{Float64,Float32}} = read(d.io, T)
 function decode!(d::AbstractProtoDecoder, buffer::Dict{K,V}) where {K,V<:_ScalarTypesEnum}

test/test_decode.jl

@@ -298,6 +298,10 @@ end
         @testset "enum" begin
             test_decode([0x02], TestEnum.C)
         end
+
+        @testset "unknown enum member" begin
+            test_decode([0x10], Core.bitcast(TestEnum.T, Int32(0x10)))
+        end
     end
 
     @testset "fixed" begin