use directory? to check rack existence

1 files changed, 3 insertions, 4 deletions

diff --git a/Library/Homebrew/cmd/outdated.rb b/Library/Homebrew/cmd/outdated.rb
index d432c4e83..7a199fcae 100644
--- a/Library/Homebrew/cmd/outdated.rb
+++ b/Library/Homebrew/cmd/outdated.rb
@@ -18,10 +18,9 @@ module Homebrew
       all_versions = []
       older_or_same_tap_versions = []
 
-      if f.oldname && !f.rack.exist? && (dir = HOMEBREW_CELLAR/f.oldname).exist?
-        if f.tap == Tab.for_keg(dir.subdirs.first).tap
-          raise Migrator::MigrationNeededError.new(f)
-        end
+      if f.oldname && !f.rack.exist? && (dir = HOMEBREW_CELLAR/f.oldname).directory? &&
+        !dir.subdirs.empty? && f.tap == Tab.for_keg(dir.subdirs.first).tap
+        raise Migrator::MigrationNeededError.new(f)
       end
 
       f.rack.subdirs.each do |keg_dir|