kernel/v1: provisioner upgrade works properly [GH-3092]

CHANGELOG.md

@@ -1,6 +1,8 @@
 ## 1.5.1 (unreleased)
 
+BUG FIXES:
 
+  - core: V1 Vagrantfiles can upgrade provisioners properly. [GH-3092]
 
 ## 1.5.0 (March 10, 2014)
 

plugins/kernel_v1/config/vm.rb

@@ -146,7 +146,8 @@ module VagrantPlugins
 
         # Provisioners
         self.provisioners.each do |name, options, block|
-          new.vm.provision(name, options, &block)
+          options ||= {}
+          new.vm.provision(name, **options, &block)
         end
 
         # Shared folders