Merge pull request #9998 from plexinc/fix_git_resource

2 files changed, 34 insertions, 4 deletions

diff --git a/lib/chef/provider/git.rb b/lib/chef/provider/git.rb
index c8b48f5602..6f5a129820 100644
--- a/lib/chef/provider/git.rb
+++ b/lib/chef/provider/git.rb
@@ -154,6 +154,11 @@ class Chef
         sha_hash?(result) ? result : nil
       end
 
+      def already_on_target_branch?
+        current_branch = git("rev-parse", "--abbrev-ref", "HEAD", cwd: cwd, returns: [0, 128]).stdout.strip
+        current_branch == (new_resource.checkout_branch || new_resource.revision)
+      end
+
       def add_remotes
         if new_resource.additional_remotes.length > 0
           new_resource.additional_remotes.each_pair do |remote_name, remote_url|
@@ -193,6 +198,9 @@ class Chef
             # detached head
             git("checkout", target_revision, cwd: cwd)
             logger.info "#{new_resource} checked out reference: #{target_revision}"
+          elsif already_on_target_branch?
+            # we are already on the proper branch
+            git("reset", "--hard", target_revision, cwd: cwd)
           else
             # need a branch with a tracking branch
             git("branch", "-f", new_resource.revision, target_revision, cwd: cwd)
@@ -222,13 +230,13 @@ class Chef
           logger.trace "Fetching updates from #{new_resource.remote} and resetting to revision #{target_revision}"
           git("fetch", "--prune", new_resource.remote, cwd: cwd)
           git("fetch", new_resource.remote, "--tags", cwd: cwd)
-          if new_resource.checkout_branch
+          if sha_hash?(new_resource.revision) || is_tag? || already_on_target_branch?
+            # detached head or if we are already on the proper branch
+            git("reset", "--hard", target_revision, cwd: cwd)
+          elsif new_resource.checkout_branch
             # check out to a local branch
             git("branch", "-f", new_resource.checkout_branch, target_revision, cwd: cwd)
             git("checkout", new_resource.checkout_branch, cwd: cwd)
-          elsif sha_hash?(new_resource.revision) || is_tag?
-            # detached head
-            git("reset", "--hard", target_revision, cwd: cwd)
           else
             # need a branch with a tracking branch
             git("branch", "-f", new_resource.revision, target_revision, cwd: cwd)
diff --git a/spec/functional/resource/git_spec.rb b/spec/functional/resource/git_spec.rb
index f8064fef20..25e5c6da4a 100644
--- a/spec/functional/resource/git_spec.rb
+++ b/spec/functional/resource/git_spec.rb
@@ -239,6 +239,28 @@ describe Chef::Resource::Git, requires_git: true do
     end
   end
 
+  context "when updating a branch that's already checked out out" do
+    it "checks out master, commits to the repo, and checks out the latest changes" do
+      git deploy_directory do
+        repository origin_repo
+        revision "master"
+        action :sync
+      end.should_be_updated
+
+      # We don't have a way to test a commit in the git bundle
+      # Revert to a previous commit in the same branch and make sure we can still sync.
+      shell_out!("git", "reset", "--hard", rev_foo, cwd: deploy_directory)
+
+      git deploy_directory do
+        repository origin_repo
+        revision "master"
+        action :sync
+      end.should_be_updated
+      expect_revision_to_be("HEAD", rev_head)
+      expect_branch_to_be("master")
+    end
+  end
+
   context "when dealing with a repo with a degenerate tag named 'HEAD'" do
     before do
       shell_out!("git", "tag", "-m\"degenerate tag\"", "HEAD", "ed181b3419b6f489bedab282348162a110d6d3a1", cwd: origin_repo)