core: box add fails early if box already exists [GH-2621]

CHANGELOG.md

@@ -14,6 +14,7 @@ BUG FIXES:
     checking a box checksum. [GH-2716]
   - core: Better error message if your plugin state file becomes corrupt
     somehow. [GH-2694]
+  - core: Box add will fail early if the box already exists. [GH-2621]
   - hosts/bsd: Only run `nfsd checkexports` if there is an exports file.
     [GH-2714]
   - commands/plugin: Fix exception that could happen rarely when installing

lib/vagrant/action/builtin/box_add.rb

@@ -20,7 +20,6 @@ module Vagrant
           @download_interrupted = false
 
           box_name = env[:box_name]
-
           box_formats = env[:box_provider]
           if box_formats
             # Determine the formats a box can support and allow the box to
@@ -32,6 +31,22 @@ module Vagrant
             end
           end
 
+          # Determine if we already have the box before downloading
+          # it again. We can only do this if we specify a format
+          if box_formats
+            begin
+              if env[:box_collection].find(box_name, box_formats)
+                raise Errors::BoxAlreadyExists,
+                  :name => box_name,
+                  :formats => [box_formats].flatten.join(", ")
+              end
+            rescue Vagrant::Errors::BoxUpgradeRequired
+              # If the box needs to be upgraded, do it.
+              env[:box_collection].upgrade(box_name)
+              retry
+            end
+          end
+
           # Determine the checksum type to use
           checksum = (env[:box_checksum] || "").to_s
           checksum_klass = nil