Add test and fix for corner case when reading chunked request body.

This seems to happen only when the first chunk is larger than 4096 bytes (the amount read from the socket at once) and when a pause happens between the CR and LF characters that follow the size part of the next chunk.

lib/puma/client.rb

@@ -147,6 +147,7 @@ module Puma
         if @partial_part_left <= chunk.size
           @body << chunk[0..(@partial_part_left-3)] # skip the \r\n
           chunk = chunk[@partial_part_left..-1]
+          @partial_part_left = 0
         else
           @body << chunk
           @partial_part_left -= chunk.size

test/test_puma_server.rb

@@ -658,6 +658,38 @@ EOF
     assert_equal "hello", body
   end
 
+  def test_chunked_request_pause_between_cr_lf_after_size_of_second_chunk
+    body = nil
+    @server.app = proc { |env|
+      body = env['rack.input'].read
+      [200, {}, [""]]
+    }
+
+    @server.add_tcp_listener @host, @port
+    @server.run
+
+    part1 = 'a' * 4200
+
+    chunked_body = "#{part1.size.to_s(16)}\r\n#{part1}\r\n1\r\nb\r\n0\r\n\r\n"
+
+    sock = TCPSocket.new @host, @server.connected_port
+    sock << "PUT /path HTTP/1.1\r\nConnection: close\r\nTransfer-Encoding: chunked\r\n\r\n"
+
+    sleep 0.1
+
+    sock << chunked_body[0..-10]
+
+    sleep 0.1
+
+    sock << chunked_body[-9..-1]
+
+    data = sock.read
+
+    assert_equal "HTTP/1.1 200 OK\r\nConnection: close\r\nContent-Length: 0\r\n\r\n", data
+    assert_equal (part1 + 'b'), body
+  end
+
+
   def test_chunked_request_header_case
     body = nil
     @server.app = proc { |env|