Include revision hash in Source::Git#to_sshow-git-rev

This effectively changes the output of commands that use Source::Git#to_s
(ie. `bundle install`). For example:

    Using rack 1.0.0 from git@github.com:rack/rack.git (at master@574b147)

Closes #3433.

1 files changed, 17 insertions, 0 deletions

diff --git a/spec/install/git_spec.rb b/spec/install/git_spec.rb
new file mode 100644
index 0000000000..7067ec4466
--- /dev/null
+++ b/spec/install/git_spec.rb
@@ -0,0 +1,17 @@
+require "spec_helper"
+
+describe "bundle install" do
+  context "git sources" do
+    it "displays the revision hash of the gem repository" do
+      build_git "foo", "1.0", :path => lib_path("foo")
+
+      install_gemfile <<-G
+        gem "foo", :git => "#{lib_path("foo")}"
+      G
+
+      bundle :install
+      expect(out).to include("Using foo 1.0 from #{lib_path("foo")} (at master@#{revision_for(lib_path("foo"))[0..6]})")
+      should_be_installed "foo 1.0"
+    end
+  end
+end