Cleanup partial message on reconnect

If a connection error occurs when part after a partial message is
received, the partial message needs to be cleaned up to prevent a
'protocol error' from occuring.

Signed-off-by: Michael Fraenkel <fraenkel@us.ibm.com>

.gitignore

@@ -6,4 +6,4 @@
 .bundle
 *.gem
 .DS_Store
-
+.idea

lib/nats/client.rb

@@ -671,6 +671,7 @@ def unbind #:nodoc:
     @reconnecting = true if connected?
     @connected = false
     @pending = @pongs = nil
+    @buf = nil
     cancel_ping_timer
 
     schedule_primary_and_connect

spec/partial_message_spec.rb

@@ -0,0 +1,47 @@
+require 'spec_helper'
+
+describe 'partial message behavior' do
+  before do
+    @s = NatsServerControl.new
+    @s.start_server
+  end
+
+  after do
+    @s.kill_server
+  end
+
+  it 'should not hold stale message data across a reconnect' do
+    got_message = false
+    expect do
+      EM.run do
+        timeout_em_on_failure(2)
+        timeout_nats_on_failure(2)
+
+        c1 = NATS.connect(:uri => @s.uri, :reconnect_time_wait => 0.25)
+        wait_on_connections([c1]) do
+          c1.subscribe('subject') do |msg|
+            got_message = true
+            msg.should eq('complete message')
+            EM.stop
+            NATS.stop
+          end
+
+          # Client receives partial message before server terminates
+          c1.receive_data("MSG subject 2 32\r\nincomplete")
+
+          @s.kill_server
+          @s.start_server
+
+          NATS.connect(:uri => @s.uri) do |c2|
+            EM.add_timer(0.25) do
+              c1.connected_server.should == @s.uri
+              c1.flush { c2.publish('subject', 'complete message') }
+            end
+          end
+        end
+      end
+    end.to_not raise_exception
+
+    got_message.should be_true
+  end
+end