Add spec for SVN directory name containing @.

Library/Homebrew/test/unpack_strategy/subversion_spec.rb

@@ -1,22 +1,26 @@
 require_relative "shared_examples"
 
 describe UnpackStrategy::Subversion do
-  let(:repo) {
-    mktmpdir.tap do |repo|
+  let(:repo) { mktmpdir }
+  let(:working_copy) { mktmpdir }
+  let(:path) { working_copy }
+
+  before(:each) do
     system "svnadmin", "create", repo
-    end
-  }
-  let(:working_copy) {
-    mktmpdir.tap do |working_copy|
+
     system "svn", "checkout", "file://#{repo}", working_copy
 
     FileUtils.touch working_copy/"test"
     system "svn", "add", working_copy/"test"
     system "svn", "commit", working_copy, "-m", "Add `test` file."
   end
-  }
-  let(:path) { working_copy }
 
   include_examples "UnpackStrategy::detect"
   include_examples "#extract", children: ["test"]
+
+  context "when the directory name contains an '@' symbol" do
+    let(:working_copy) { mktmpdir(["", "@1.2.3"])  }
+
+    include_examples "#extract", children: ["test"]
+  end
 end