Avoid fetching an rebuilding git gems when it's not necessary

2 files changed, 7 insertions, 1 deletions

diff --git a/lib/bundler/source/git.rb b/lib/bundler/source/git.rb
index 0b00608bdd..33f0af89ee 100644
--- a/lib/bundler/source/git.rb
+++ b/lib/bundler/source/git.rb
@@ -260,7 +260,11 @@ module Bundler
       end
 
       def requires_checkout?
-        allow_git_ops? && !local?
+        !cached_revision_checked_out? && allow_git_ops? && !local?
+      end
+
+      def cached_revision_checked_out?
+        cached_revision && cached_revision == revision && install_path.exist?
       end
 
       def base_name
diff --git a/spec/install/gemfile/git_spec.rb b/spec/install/gemfile/git_spec.rb
index 7f7a1ae4c9..843a177af4 100644
--- a/spec/install/gemfile/git_spec.rb
+++ b/spec/install/gemfile/git_spec.rb
@@ -1211,6 +1211,7 @@ In Gemfile:
 
       install_gemfile <<-G
         source "file://#{gem_repo1}"
+        gem "rack", "0.9.1"
         gem "foo", :git => "#{lib_path("foo-1.0")}"
       G
 
@@ -1224,6 +1225,7 @@ In Gemfile:
 
       install_gemfile <<-G
         source "file://#{gem_repo1}"
+        gem "rack", "1.0.0"
         gem "foo", :git => "#{lib_path("foo-1.0")}"
       G