Ensure internal trigger fire does not get called if plugin installed

This commit wraps up the internal machine action level trigger calls if
the community vagrant-trigger plugin is installed.

lib/vagrant/machine.rb

@@ -160,7 +160,11 @@ module Vagrant
     #   as extra data set on the environment hash for the middleware
     #   runner.
     def action(name, opts=nil)
-      @triggers.fire_triggers(name, :before, @name.to_s)
+      plugins = Vagrant::Plugin::Manager.instance.installed_plugins
+      if !plugins.keys.include?("vagrant-triggers")
+        @triggers.fire_triggers(name, :before, @name.to_s)
+      end
+
       @logger.info("Calling action: #{name} on provider #{@provider}")
 
       opts ||= {}
@@ -206,7 +210,9 @@ module Vagrant
         action_result
       end
 
-      @triggers.fire_triggers(name, :after, @name.to_s)
+      if !plugins.keys.include?("vagrant-triggers")
+        @triggers.fire_triggers(name, :after, @name.to_s)
+      end
       # preserve returning environment after machine action runs
       return return_env
     rescue Errors::EnvironmentLockedError

test/unit/vagrant/machine_test.rb

@@ -265,6 +265,10 @@ describe Vagrant::Machine do
   end
 
   describe "#action" do
+    before do
+      allow(Vagrant::Plugin::Manager.instance).to receive(:installed_plugins).and_return({})
+    end
+
     it "should be able to run an action that exists" do
       action_name = :up
       called      = false
@@ -387,6 +391,32 @@ describe Vagrant::Machine do
         expect(subject.ui).to_not have_received(:warn)
       end
     end
+
+    context "with the vagrant-triggers community plugin" do
+      it "should not call the internal trigger functions if installed" do
+        action_name = :up
+        callable    = lambda { |_env| }
+
+        allow(provider).to receive(:action).with(action_name).and_return(callable)
+        allow(Vagrant::Plugin::Manager.instance).to receive(:installed_plugins)
+          .and_return({"vagrant-triggers"=>"stuff"})
+
+        expect(instance.instance_variable_get(:@triggers)).not_to receive(:fire_triggers)
+        instance.action(action_name)
+      end
+
+      it "should call the internal trigger functions if not installed" do
+        action_name = :up
+        callable    = lambda { |_env| }
+
+        allow(provider).to receive(:action).with(action_name).and_return(callable)
+        allow(Vagrant::Plugin::Manager.instance).to receive(:installed_plugins)
+          .and_return({})
+
+        expect(instance.instance_variable_get(:@triggers)).to receive(:fire_triggers).twice
+        instance.action(action_name)
+      end
+    end
   end
 
   describe "#action_raw" do