(MODULES-660) Correct detached HEAD on latest

Previously vcsrepo detached HEAD on checkout which caused further branch
revisions to fail. This corrects the behavior, and works on git 1.7,
1.8, 1.9, and 2.0

1 files changed, 99 insertions, 73 deletions

diff --git a/lib/puppet/provider/vcsrepo/git.rb b/lib/puppet/provider/vcsrepo/git.rb
index 5c5dd07..0a142bb 100644
--- a/lib/puppet/provider/vcsrepo/git.rb
+++ b/lib/puppet/provider/vcsrepo/git.rb
@@ -31,69 +31,49 @@ Puppet::Type.type(:vcsrepo).provide(:git, :parent => Puppet::Provider::Vcsrepo)
     FileUtils.rm_rf(@resource.value(:path))
   end
 
+  # Checks to see if the current revision is equal to the revision on the
+  # remote (whether on a branch, tag, or reference)
+  #
+  # @return [Boolean] Returns true if the repo is on the latest revision
   def latest?
-    at_path do
-      return self.revision == self.latest
-    end
+    return revision == latest_revision
   end
 
+  # Just gives the `should` value that we should be setting the repo to if
+  # latest? returns false
+  #
+  # @return [String] Returns the target sha/tag/branch
   def latest
-    branch = on_branch?
-    if !branch
-      return get_revision('HEAD')
-    else
-      return get_revision("#{@resource.value(:remote)}/#{branch}")
-    end
+    @resource.value(:revision)
   end
 
+  # Get the current revision of the repo (tag/branch/sha)
+  #
+  # @return [String] Returns the branch/tag if the current sha matches the
+  #                  remote; otherwise returns the current sha.
   def revision
-    update_references
-    current = at_path { git_with_identity('rev-parse', 'HEAD').chomp }
-    return current unless @resource.value(:revision)
-
-    if tag_revision?(@resource.value(:revision))
-      # git-rev-parse will give you the hash of the tag object itself rather than the commit it points to by default.
-      # Using tag^0 will return the actual commit.
-      canonical = at_path { git_with_identity('rev-parse', "#{@resource.value(:revision)}^0").chomp }
-    else
-      # if it's not a tag, look for it as a local ref
-      canonical = at_path { git_with_identity('rev-parse', '--revs-only', @resource.value(:revision)).chomp }
-      if canonical.empty?
-        # git rev-parse executed properly but didn't find the ref;
-        # look for it in the remote
-        remote_ref = at_path { git_with_identity('ls-remote', '--heads', '--tags', @resource.value(:remote), @resource.value(:revision)).chomp }
-        if remote_ref.empty?
-          fail("#{@resource.value(:revision)} is not a local or remote ref")
-        end
-
-        # $ git ls-remote --heads --tags origin feature/cvs
-        # 7d4244b35e72904e30130cad6d2258f901c16f1a	refs/heads/feature/cvs
-        canonical = remote_ref.split.first
-      end
-    end
-
-    if current == canonical
-      @resource.value(:revision)
-    else
-      current
-    end
+    #HEAD is the default, but lets just be explicit here.
+    get_revision('HEAD')
   end
 
+  # Is passed the desired reference, whether a tag, rev, or branch. Should
+  # handle transitions from a rev/branch/tag to a rev/branch/tag. Detached
+  # heads should be treated like bare revisions.
+  #
+  # @param [String] desired The desired revision to which the repo should be
+  #                         set.
   def revision=(desired)
+    #just checkout tags and shas; fetch has already happened so they should be updated.
     checkout(desired)
-    if local_branch_revision?
-      # reset instead of pull to avoid merge conflicts. assuming remote is
-      # authoritative.
-      # might be worthwhile to have an allow_local_changes param to decide
-      # whether to reset or pull when we're ensuring latest.
-      at_path {
-        git_with_identity('reset', '--hard', "#{@resource.value(:remote)}/#{desired}")
-        if detached?
-          git_with_identity('checkout', "#{@resource.value(:revision)}")
-          git_with_identity('pull')
-        end
-      }
+    #branches require more work.
+    if local_branch_revision?(desired)
+      #reset instead of pull to avoid merge conflicts. assuming remote is
+      #updated and authoritative.
+      #TODO might be worthwhile to have an allow_local_changes param to decide
+      #whether to reset or pull when we're ensuring latest.
+      at_path { git_with_identity('reset', '--hard', "#{@resource.value(:remote)}/#{desired}") }
     end
+    #TODO Would this ever reach here if it is bare?
     if @resource.value(:ensure) != :bare
       update_submodules
     end
@@ -132,10 +112,12 @@ Puppet::Type.type(:vcsrepo).provide(:git, :parent => Puppet::Provider::Vcsrepo)
 
   private
 
+  # @!visibility private
   def bare_git_config_exists?
     File.exist?(File.join(@resource.value(:path), 'config'))
   end
 
+  # @!visibility private
   def clone_repository(source, path)
     check_force
     args = ['clone']
@@ -158,6 +140,7 @@ Puppet::Type.type(:vcsrepo).provide(:git, :parent => Puppet::Provider::Vcsrepo)
     end
   end
 
+  # @!visibility private
   def check_force
     if path_exists? and not path_empty?
       if @resource.value(:force)
@@ -169,6 +152,7 @@ Puppet::Type.type(:vcsrepo).provide(:git, :parent => Puppet::Provider::Vcsrepo)
     end
   end
 
+  # @!visibility private
   def init_repository(path)
     check_force
     if @resource.value(:ensure) == :bare && working_copy_exists?
@@ -195,6 +179,7 @@ Puppet::Type.type(:vcsrepo).provide(:git, :parent => Puppet::Provider::Vcsrepo)
   #   <path>/.git
   # to:
   #   <path>/
+  # @!visibility private
   def convert_working_copy_to_bare
     notice "Converting working copy repository to bare repository"
     FileUtils.mv(File.join(@resource.value(:path), '.git'), tempdir)
@@ -208,6 +193,7 @@ Puppet::Type.type(:vcsrepo).provide(:git, :parent => Puppet::Provider::Vcsrepo)
   #   <path>/
   # to:
   #   <path>/.git
+  # @!visibility private
   def convert_bare_to_working_copy
     notice "Converting bare repository to working copy repository"
     FileUtils.mv(@resource.value(:path), tempdir)
@@ -220,6 +206,7 @@ Puppet::Type.type(:vcsrepo).provide(:git, :parent => Puppet::Provider::Vcsrepo)
     end
   end
 
+  # @!visibility private
   def commits_in?(dot_git)
     Dir.glob(File.join(dot_git, 'objects/info/*'), File::FNM_DOTMATCH) do |e|
       return true unless %w(. ..).include?(File::basename(e))
@@ -227,26 +214,35 @@ Puppet::Type.type(:vcsrepo).provide(:git, :parent => Puppet::Provider::Vcsrepo)
     false
   end
 
+  # Will checkout a rev/branch/tag using the locally cached versions. Does not
+  # handle upstream branch changes
+  # @!visibility private
   def checkout(revision = @resource.value(:revision))
     if !local_branch_revision? && remote_branch_revision?
-      at_path { git_with_identity('checkout', '-b', revision, '--track', "#{@resource.value(:remote)}/#{revision}") }
+      #non-locally existant branches (perhaps switching to a branch that has never been checked out)
+      at_path { git_with_identity('checkout', '--force', '-b', revision, '--track', "#{@resource.value(:remote)}/#{revision}") }
     else
+      #tags, locally existant branches (perhaps outdated), and shas
       at_path { git_with_identity('checkout', '--force', revision) }
     end
   end
 
+  # @!visibility private
   def reset(desired)
     at_path do
       git_with_identity('reset', '--hard', desired)
     end
   end
 
+  # @!visibility private
   def update_submodules
     at_path do
       git_with_identity('submodule', 'update', '--init', '--recursive')
     end
   end
 
+  # Determins if the branch exists at the upstream but has not yet been locally committed
+  # @!visibility private
   def remote_branch_revision?(revision = @resource.value(:revision))
     # git < 1.6 returns '#{@resource.value(:remote)}/#{revision}'
     # git 1.6+ returns 'remotes/#{@resource.value(:remote)}/#{revision}'
@@ -254,64 +250,93 @@ Puppet::Type.type(:vcsrepo).provide(:git, :parent => Puppet::Provider::Vcsrepo)
     branch unless branch.empty?
   end
 
+  # Determins if the branch is already cached locally
+  # @!visibility private
   def local_branch_revision?(revision = @resource.value(:revision))
     at_path { branches.include?(revision) }
   end
 
+  # @!visibility private
   def tag_revision?(revision = @resource.value(:revision))
     at_path { tags.include?(revision) }
   end
 
+  # @!visibility private
   def branches
     at_path { git_with_identity('branch', '-a') }.gsub('*', ' ').split(/\n/).map { |line| line.strip }
   end
 
+  # @!visibility private
   def on_branch?
     at_path {
       matches = git_with_identity('branch', '-a').match /\*\s+(.*)/
-      matches[1] unless matches[1].match /detached/
-    }
-  end
-
-  def detached?
-    at_path {
-      git_with_identity('branch', '-a').match /\*\s+\(detached from.*\)/
+      matches[1] unless matches[1].match /(\(detached from|\(no branch)/
     }
   end
 
+  # @!visibility private
   def tags
     at_path { git_with_identity('tag', '-l') }.split(/\n/).map { |line| line.strip }
   end
 
+  # @!visibility private
   def set_excludes
     at_path { open('.git/info/exclude', 'w') { |f| @resource.value(:excludes).each { |ex| f.write(ex + "\n") }}}
   end
 
-  def get_revision(rev)
-    if @resource.value(:force) && working_copy_exists?
-      create
-    end
-    if !working_copy_exists?
-      create
-    end
-    at_path do
-      update_remote_origin_url
-      git_with_identity('fetch', @resource.value(:remote))
-      git_with_identity('fetch', '--tags', @resource.value(:remote))
+  # Finds the latest revision or sha of the current branch if on a branch, or
+  # of HEAD otherwise.
+  # @note Calls create which can forcibly destroy and re-clone the repo if
+  #       force => true
+  # @see get_revision
+  #
+  # @!visibility private
+  # @return [String] Returns the output of get_revision
+  def latest_revision
+    #TODO Why is create called here anyway?
+    create if @resource.value(:force) && working_copy_exists?
+    create if !working_copy_exists?
+
+    if branch = on_branch?
+      return get_revision("#{@resource.value(:remote)}/#{branch}")
+    else
+      return get_revision
     end
+  end
+
+  # Returns the current revision given if the revision is a tag or branch and
+  # matches the current sha. If the current sha does not match the sha of a tag
+  # or branch, then it will just return the sha (ie, is not in sync)
+  #
+  # @!visibility private
+  #
+  # @param [String] rev The revision of which to check if it is current
+  # @return [String] Returns the tag/branch of the current repo if it's up to
+  #                  date; otherwise returns the sha of the requested revision.
+  def get_revision(rev = 'HEAD')
+    update_references
     current = at_path { git_with_identity('rev-parse', rev).strip }
     if @resource.value(:revision)
-      if local_branch_revision?
+      if tag_revision?
+        # git-rev-parse will give you the hash of the tag object itself rather
+        # than the commit it points to by default. Using tag^0 will return the
+        # actual commit.
+        canonical = at_path { git_with_identity('rev-parse', "#{@resource.value(:revision)}^0").strip }
+      elsif local_branch_revision?
         canonical = at_path { git_with_identity('rev-parse', @resource.value(:revision)).strip }
       elsif remote_branch_revision?
-        canonical = at_path { git_with_identity('rev-parse', "#{@resource.value(:remote)}/" + @resource.value(:revision)).strip }
+        canonical = at_path { git_with_identity('rev-parse', "#{@resource.value(:remote)}/#{@resource.value(:revision)}").strip }
+      else
+        #look for a sha (could match invalid shas)
+        canonical = at_path { git_with_identity('rev-parse', '--revs-only', @resource.value(:revision)).strip }
       end
+      fail("#{@resource.value(:revision)} is not a local or remote ref") if canonical.nil? or canonical.empty?
       current = @resource.value(:revision) if current == canonical
     end
-    update_owner_and_excludes
     return current
   end
 
+  # @!visibility private
   def update_owner_and_excludes
     if @resource.value(:owner) or @resource.value(:group)
       set_ownership
@@ -321,6 +346,7 @@ Puppet::Type.type(:vcsrepo).provide(:git, :parent => Puppet::Provider::Vcsrepo)
     end
   end
 
+  # @!visibility private
   def git_with_identity(*args)
     if @resource.value(:identity)
       Tempfile.open('git-helper') do |f|