[bundler/bundler] Fix open default gem error

https://github.com/bundler/bundler/commit/792d724752

lib/bundler/cli/open.rb

@@ -15,11 +15,15 @@ module Bundler
       return Bundler.ui.info("To open a bundled gem, set $EDITOR or $BUNDLER_EDITOR") unless editor
       return unless spec = Bundler::CLI::Common.select_spec(name, :regex_match)
       path = spec.full_gem_path
-      Dir.chdir(path) do
-        command = Shellwords.split(editor) + [path]
-        Bundler.with_original_env do
-          system(*command)
-        end || Bundler.ui.info("Could not run '#{command.join(" ")}'")
+      if spec.default_gem?
+        Bundler.ui.info "Unable to open #{name} because it's a default gem, so the directory it would normally be installed to does not exist."
+      else
+        Dir.chdir(path) do
+          command = Shellwords.split(editor) + [path]
+          Bundler.with_original_env do
+            system(*command)
+          end || Bundler.ui.info("Could not run '#{command.join(" ")}'")
+        end
       end
     end
   end

spec/bundler/commands/open_spec.rb

@@ -91,4 +91,17 @@ RSpec.describe "bundle open" do
       expect(out).not_to include("BUNDLE_GEMFILE=")
     end
   end
+
+  context "when opening a default gem" do
+    before do
+      install_gemfile <<-G
+        gem "json"
+      G
+    end
+
+    it "throws proper error when trying to open default gem" do
+      bundle "open json", :env => { "EDITOR" => "echo editor", "VISUAL" => "echo visual", "BUNDLER_EDITOR" => "echo bundler_editor" }
+      expect(out).to include("Unable to open json because it's a default gem, so the directory it would normally be installed to does not exist.")
+    end
+  end
 end