Use @callback to track the state of the invocation.

Setting `@body = nil` can cause other operations to fail.

lib/protocol/http/body/completable.rb

@@ -25,24 +25,20 @@ def initialize(body, callback)
 				end
 
 				def finish
-					if @body
-						result = super
-
-						@callback.call
-
-						@body = nil
-
-						return result
+					super.tap do
+						if @callback
+							@callback.call
+							@callback = nil
+						end
 					end
 				end
 
 				def close(error = nil)
-					if @body
-						super
-
-						@callback.call(error)
-
-						@body = nil
+					super.tap do
+						if @callback
+							@callback.call(error)
+							@callback = nil
+						end
 					end
 				end
 			end

test/protocol/http/body/completable.rb

@@ -5,6 +5,7 @@
 
 require 'protocol/http/body/completable'
 require 'protocol/http/body/buffered'
+require 'protocol/http/request'
 
 describe Protocol::HTTP::Body::Completable do
 	let(:body) {Protocol::HTTP::Body::Buffered.new}
@@ -76,5 +77,10 @@
 				completable.finish
 			end
 		end
+
+		it "doesn't break #read after finishing" do
+			completable.finish
+			expect(completable.read).to be_nil
+		end
 	end
 end