core: SSHExec middleware can have ssh info overridden

lib/vagrant/action/builtin/ssh_exec.rb

@@ -21,8 +21,9 @@ module Vagrant
         end
 
         def call(env)
-          # Grab the SSH info from the machine
+          # Grab the SSH info from the machine or the environment
-          info = env[:machine].ssh_info
+          info = env[:ssh_info]
+          info ||= env[:machine].ssh_info
 
           # If the result is nil, then the machine is telling us that it is
           # not yet ready for SSH, so we raise this exception.

test/unit/vagrant/action/builtin/ssh_exec_test.rb

@@ -46,6 +46,16 @@ describe Vagrant::Action::Builtin::SSHExec do
     described_class.new(app, env).call(env)
   end
 
+  it "should exec with the SSH info in the env if given" do
+    ssh_info = { foo: :bar }
+
+    expect(ssh_klass).to receive(:exec).
+      with(ssh_info, nil)
+
+    env[:ssh_info] = ssh_info
+    described_class.new(app, env).call(env)
+  end
+
   it "should exec with the options given in `ssh_opts`" do
     ssh_opts = { :foo => :bar }