Add tests for Gemfile hashing, fix hashing logic

lib/bundler/definition.rb

@@ -137,7 +137,7 @@ def specs_for(groups)
 
     def resolve
       @resolve ||= begin
-        if Bundler.settings[:frozen]
+        if Bundler.settings[:frozen] || lock_current?
           @locked_specs
         else
           last_resolve = converge_locked_specs
@@ -151,24 +151,24 @@ def resolve
             source_requirements[dep.name] = dep.source.specs
           end
 
-          # Only run a resolve against the locally available gems if Gemfile has changed
-          # since the last resolve
-          return last_resolve unless gemfile_changed?
-
-          # If it's changed, update hash and rerun resolve
           Bundler.settings[:gemfile_hash] = gemfile_hash
-          last_resolve.merge Resolver.resolve(expanded_dependencies, index, source_requirements, last_resolve)        end
+          last_resolve.merge Resolver.resolve(expanded_dependencies, index, source_requirements, last_resolve)
+        end
       end
     end
 
-    def gemfile_changed?
-      Digest::MD5.hexdigest(File.read(Bundler.default_gemfile)) == Bundler.settings[:gemfile_hash] 
+    def gemfile_hash
+      Digest::MD5.hexdigest(Bundler.default_gemfile.read)
+    end
+
+    def lock_current?
+      Bundler.settings[:gemfile_hash] == gemfile_hash && Bundler.default_lockfile.exist?
     end
 
     def index
       @index ||= Index.build do |idx|
         @sources.each do |s|
-          idx.use s.specs
+          idx.use s.specs(@dependencies)
         end
       end
     end

spec/install/gems/resolving_spec.rb

@@ -69,4 +69,33 @@
       end
     end
   end
-end
+
+  context "Gemfile hashing" do
+    before do
+      build_lib('foo')
+      install_gemfile <<-G, :expect_err => true
+        source "file://#{gem_repo1}"
+        gem "foo", :path => "#{lib_path('foo-1.0')}"
+      G
+    end
+
+    it "when Gemfile changes it reruns the resolver" do
+      install_gemfile <<-G, :expect_err => true, :env => {"DEBUG_RESOLVER" => true }
+        gem "foo", :path => "#{lib_path('foo-1.0')}"
+      G
+      err.should_not == ""
+    end
+
+    it "if the Gemfile has not changed don't rerun the resolver" do
+      bundle :install, :env => {"DEBUG_RESOLVER" => true }
+      err.should == ""
+    end
+
+    it "if the Gemfile.lock does not exist, generate one" do
+      bundled_app('Gemfile.lock').rmtree
+
+      bundle :install, :expect_err => true, :env => {"DEBUG_RESOLVER" => true }
+      err.should_not == ""
+    end
+  end
+end