kernel/v2: multiple synced folder lines override each other

plugins/kernel_v2/config/vm.rb

@@ -184,9 +184,11 @@ module VagrantPlugins
         end
 
         options ||= {}
-        options = options.dup
         options[:guestpath] = guestpath.to_s.gsub(/\/$/, '')
         options[:hostpath]  = hostpath
+        options = (@__synced_folders[options[:guestpath]] || {}).
+          merge(options.dup)
+
         # Make sure the type is a symbol
         options[:type] = options[:type].to_sym if options[:type]
 

test/unit/plugins/kernel_v2/config/vm_test.rb

@@ -410,6 +410,17 @@ describe VagrantPlugins::Kernel_V2::VMConfig do
       expect(sf).to have_key("/vagrant")
       expect(sf["/vagrant"][:disabled]).to be_true
     end
+
+    it "allows overriding previously set options" do
+      subject.synced_folder(".", "/vagrant", disabled: true)
+      subject.synced_folder(".", "/vagrant", foo: :bar)
+      subject.finalize!
+      sf = subject.synced_folders
+      expect(sf.length).to eq(1)
+      expect(sf).to have_key("/vagrant")
+      expect(sf["/vagrant"][:disabled]).to be_true
+      expect(sf["/vagrant"][:foo]).to eq(:bar)
+    end
   end
 
   describe "#usable_port_range" do