commands/rsync-auto: check machine ID prior to sync [GH-4031]

CHANGELOG.md

@@ -26,6 +26,7 @@ BUG FIXES:
       but this fixes a few. [GH-4159]
   - core: Fix crash case when destroying with an invalid provisioner. [GH-4281]
   - commands/package: base package won't crash with exception [GH-4017]
+  - commands/rsync-auto: Destroyed machines won't raise exceptions. [GH-4031]
   - communicators/winrm: Support `mkdir` [GH-4271]
   - guests/centos: Fix issues when NFS client is installed by restarting
       NFS [GH-4088]

plugins/synced_folders/rsync/command/rsync_auto.rb

@@ -156,6 +156,13 @@ module VagrantPlugins
           # Sync all the folders that need to be synced
           tosync.each do |folders|
             folders.each do |opts|
+              # Reload so we get the latest ID
+              opts[:machine].reload
+              if !opts[:machine].id || opts[:machine].id == ""
+                # Skip since we can't get SSH info without an ID
+                next
+              end
+
               ssh_info = opts[:machine].ssh_info
               begin
                 RsyncHelper.rsync_single(opts[:machine], ssh_info, opts[:opts])

test/unit/plugins/synced_folders/rsync/command/rsync_auto_test.rb

@@ -29,6 +29,8 @@ describe VagrantPlugins::SyncedFolderRSync::Command::RsyncAuto do
 
     def machine_stub(name)
       double(name).tap do |m|
+        m.stub(id: "foo")
+        m.stub(reload: nil)
         m.stub(ssh_info: ssh_info)
         m.stub(ui: double("ui"))
 
@@ -120,5 +122,22 @@ describe VagrantPlugins::SyncedFolderRSync::Command::RsyncAuto do
       expect { subject.callback(paths, m, a, r) }.
         to_not raise_error
     end
+
+    it "doesn't sync machines with no ID" do
+      paths["/foo"] = [
+        { machine: machine_stub("m1"), opts: double("opts_m1") },
+      ]
+
+      paths["/foo"].each do |data|
+        data[:machine].stub(id: nil)
+        expect(helper_class).to_not receive(:rsync_single)
+      end
+
+      m = []
+      a = []
+      r = ["/foo/bar"]
+      expect { subject.callback(paths, m, a, r) }.
+        to_not raise_error
+    end
   end
 end