core: execute SSH commands in context of login shell [GH-2636]

CHANGELOG.md

@@ -10,6 +10,8 @@ IMPROVEMENTS:
 BUG FIXES:
 
   - core: box removal of a V1 box works
+  - core: `vagrant ssh -c` commands are now executed in the context of
+    a login shell (regression). [GH-2636]
   - guests/debian: fix `use_dhcp_assigned_default_route` to work properly.
     [GH-2648]
   - guests/debian,ubuntu: fix change\_host\_name for FQDNs with trailing

lib/vagrant/action/builtin/ssh_run.rb

@@ -32,8 +32,14 @@ module Vagrant
             end
           end
 
-          # Execute!
+          # Get the command and wrap it in a login shell
           command = env[:ssh_run_command]
+          command = command.gsub(/'/) do |m|
+            "#{m}\\#{m}#{m}"
+          end
+          command = "#{env[:machine].config.ssh.shell} -c '#{command}'"
+
+          # Execute!
           opts = env[:ssh_opts] || {}
           opts[:extra_args] = ["-t", command]
           opts[:subprocess] = true