branch and merge: combine checkout and branch logic

1 files changed, 37 insertions, 48 deletions

diff --git a/morphlib/plugins/branch_and_merge_plugin.py b/morphlib/plugins/branch_and_merge_plugin.py
index 8d0e3eef..87565570 100644
--- a/morphlib/plugins/branch_and_merge_plugin.py
+++ b/morphlib/plugins/branch_and_merge_plugin.py
@@ -505,27 +505,15 @@ class BranchAndMergePlugin(cliapp.Plugin):
         os.mkdir(os.path.join(dirname, '.morph'))
         self.app.status(msg='Initialized morph workspace', chatty=True)
 
-    def branch(self, args):
-        '''Create a new system branch.'''
-
-        if len(args) not in [2, 3]:
-            raise cliapp.AppException('morph branch needs name of branch '
-                                      'as parameter')
-
-        repo = args[0]
-        new_branch = args[1]
-        commit = 'master' if len(args) == 2 else args[2]
-
-        self.lrc, self.rrc = morphlib.util.new_repo_caches(self.app)
-        if self.lrc.get_repo(repo).ref_exists(new_branch):
-            raise cliapp.AppException('branch %s already exists in '
-                                      'repository %s' % (new_branch, repo))
-
-        # Create the system branch directory.
-        workspace = self.deduce_workspace()
-        branch_dir = os.path.join(workspace, new_branch)
+    def _create_branch(self, workspace, branch_name, repo, original_ref):
+        '''Create a branch called branch_name based off original_ref.
+           
+           NOTE: self.lrc and self.rrc need to be initialized before
+                 calling since clone_to_directory uses them indirectly via
+                 get_cached_repo
+        '''
+        branch_dir = os.path.join(workspace, branch_name)
         os.makedirs(branch_dir)
-
         try:
             # Create a .morph-system-branch directory to clearly identify
             # this directory as a morph system branch.
@@ -533,7 +521,7 @@ class BranchAndMergePlugin(cliapp.Plugin):
 
             # Remember the system branch name and the repository we branched
             # off from initially.
-            self.set_branch_config(branch_dir, 'branch.name', new_branch)
+            self.set_branch_config(branch_dir, 'branch.name', branch_name)
             self.set_branch_config(branch_dir, 'branch.root', repo)
 
             # Generate a UUID for the branch. We will use this for naming
@@ -542,15 +530,36 @@ class BranchAndMergePlugin(cliapp.Plugin):
 
             # Clone into system branch directory.
             repo_dir = os.path.join(branch_dir, self.convert_uri_to_path(repo))
-            self.clone_to_directory(repo_dir, repo, commit)
+            self.clone_to_directory(repo_dir, repo, original_ref)
 
             # Create a new branch in the local morphs repository.
-            self.app.runcmd(['git', 'checkout', '-b', new_branch, commit],
-                            cwd=repo_dir)
+            if original_ref != branch_name:
+                self.app.runcmd(['git', 'checkout', '-b', branch_name,
+                                 original_ref], cwd=repo_dir)
         except:
-            self.remove_branch_dir_safe(workspace, new_branch)
+            self.remove_branch_dir_safe(workspace, branch_name)
             raise
 
+    def branch(self, args):
+        '''Create a new system branch.'''
+
+        if len(args) not in [2, 3]:
+            raise cliapp.AppException('morph branch needs name of branch '
+                                      'as parameter')
+
+        repo = args[0]
+        new_branch = args[1]
+        commit = 'master' if len(args) == 2 else args[2]
+
+        self.lrc, self.rrc = morphlib.util.new_repo_caches(self.app)
+        if self.lrc.get_repo(repo).ref_exists(new_branch):
+            raise cliapp.AppException('branch %s already exists in '
+                                      'repository %s' % (new_branch, repo))
+
+        # Create the system branch directory.
+        workspace = self.deduce_workspace()
+        self._create_branch(workspace, new_branch, repo, commit)
+
     def checkout(self, args):
         '''Check out an existing system branch.'''
 
@@ -561,31 +570,11 @@ class BranchAndMergePlugin(cliapp.Plugin):
         repo = args[0]
         system_branch = args[1]
 
-        # Create the system branch directory.
-        workspace = self.deduce_workspace()
-        branch_dir = os.path.join(workspace, system_branch)
-        os.makedirs(branch_dir)
         self.lrc, self.rrc = morphlib.util.new_repo_caches(self.app)
 
-        try:
-            # Create a .morph-system-branch directory to clearly identify
-            # this directory as a morph system branch.
-            os.mkdir(os.path.join(branch_dir, '.morph-system-branch'))
-
-            # Remember the system branch name and the repository we
-            # branched off from.
-            self.set_branch_config(branch_dir, 'branch.name', system_branch)
-            self.set_branch_config(branch_dir, 'branch.root', repo)
-
-            # Generate a UUID for the branch.
-            self.set_branch_config(branch_dir, 'branch.uuid', uuid.uuid4().hex)
-
-            # Clone into system branch directory.
-            repo_dir = os.path.join(branch_dir, self.convert_uri_to_path(repo))
-            self.clone_to_directory(repo_dir, repo, system_branch)
-        except:
-            self.remove_branch_dir_safe(workspace, system_branch)
-            raise
+        # Create the system branch directory.
+        workspace = self.deduce_workspace()
+        self._create_branch(workspace, system_branch, repo, system_branch)
 
     def checkout_repository(self, branch_dir, repo, ref, parent_ref=None):
         '''Make a chunk or stratum repository available for a system branch