More tests.

lib/protocol/http/body/stream.rb

@@ -95,15 +95,18 @@ def read_partial(length = nil, buffer = nil)
 								buffer.replace(@buffer)
 							else
 								buffer = @buffer
-								@buffer = nil
 							end
+							@buffer = nil
 						else
-							chunk = read_next
-
-							if buffer and chunk
-								buffer.replace(chunk)
+							if chunk = read_next
+								if buffer
+									buffer.replace(chunk)
+								else
+									buffer = chunk
+								end
 							else
-								buffer = chunk
+								buffer&.clear
+								buffer = nil
 							end
 						end
 

test/protocol/http/body/stream.rb

@@ -121,6 +121,24 @@
 			expect(stream.read_partial(2)).to be == "d"
 			expect(stream.read_partial(2)).to be == nil
 		end
+
+		it "can read partial input with buffer" do
+			buffer = String.new
+			expect(stream.read_partial(2, buffer)).to be == "He"
+			expect(buffer).to be == "He"
+			expect(stream.read_partial(2, buffer)).to be == "ll"
+			expect(buffer).to be == "ll"
+			expect(stream.read_partial(2, buffer)).to be == "o"
+			expect(buffer).to be == "o"
+			expect(stream.read_partial(2, buffer)).to be == "Wo"
+			expect(buffer).to be == "Wo"
+			expect(stream.read_partial(2, buffer)).to be == "rl"
+			expect(buffer).to be == "rl"
+			expect(stream.read_partial(2, buffer)).to be == "d"
+			expect(buffer).to be == "d"
+			expect(stream.read_partial(2, buffer)).to be == nil
+			expect(buffer).to be == ""
+		end
 	end
 
 	with '#readpartial' do