1 files changed, 13 insertions, 0 deletions
diff --git a/lib/bundler/index.rb b/lib/bundler/index.rb
index 5f54796fa2..fd4dea32e7 100644
--- a/lib/bundler/index.rb
+++ b/lib/bundler/index.rb
@@ -131,6 +131,19 @@ module Bundler
       names.uniq
     end
 
+    def dependency_names_if_available
+      reduce([]) do |names, spec|
+        case spec
+        when EndpointSpecification, Gem::Specification, LazySpecification, StubSpecification
+          names.concat(spec.dependencies)
+        when RemoteSpecification # from the full index
+          return nil
+        else
+          raise "unhandled spec type in #dependency_names_if_available (#{spec.inspect})"
+        end
+      end.tap {|n| n && n.map!(&:name) }
+    end
+
     def use(other, override_dupes = false)
       return unless other
       other.each do |s|