commands/box/add: add --clean flag to ignore continuation

lib/vagrant/action/builtin/box_add.rb

@@ -35,9 +35,17 @@ module Vagrant
 
           # If the temporary path exists, verify it is not too old. If its
           # too old, delete it first because the data may have changed.
-          if @temp_path.file? && @temp_path.mtime.to_i < (Time.now.to_i - 6 * 60 * 60)
-            @logger.info("Existing temp file is too old. Removing.")
-            @temp_path.unlink
+          if @temp_path.file?
+            delete = false
+            if env[:box_clean]
+              @logger.info("Cleaning existing temp box file.")
+              delete = true
+            elsif @temp_path.mtime.to_i < (Time.now.to_i - 6 * 60 * 60)
+              @logger.info("Existing temp file is too old. Removing.")
+              delete = true
+            end
+
+            @temp_path.unlink if delete
           end
 
           # Download the box to a temporary path. We store the temporary

plugins/commands/box/command/add.rb

@@ -11,6 +11,10 @@ module VagrantPlugins
             o.banner = "Usage: vagrant box add <name> <url> [--provider provider] [-h]"
             o.separator ""
 
+            o.on("-c", "--clean", "Remove old temporary download if it exists.") do |c|
+              options[:clean] = c
+            end
+
             o.on("-f", "--force", "Overwrite an existing box if it exists.") do |f|
               options[:force] = f
             end
@@ -38,6 +42,7 @@ module VagrantPlugins
             :box_name     => argv[0],
             :box_provider => provider,
             :box_url      => argv[1],
+            :box_clean    => options[:clean],
             :box_force    => options[:force],
             :box_download_insecure => options[:insecure],
           })