Make sure switch_branch uses the right __head

[stgit] / stgit / git.py

diff --git a/stgit/git.py b/stgit/git.py
index c57063b9eacae5ed82da7a6530eeb59167d6dc0e..33702cbc27ef0529526a06962e7277e01fb20299 100644 (file)
--- a/stgit/git.py
+++ b/stgit/git.py
@@ -18,7 +18,7 @@ along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 """
 
-import sys, os, glob, popen2
+import sys, os, popen2
 
 from stgit.utils import *
 
@@ -233,14 +233,31 @@ def get_head_file():
     """
     return os.path.basename(_output_one_line('git-symbolic-ref HEAD'))
 
+def set_head_file(ref):
+    """Resets HEAD to point to a new ref
+    """
+    # head cache flushing is needed since we might have a different value
+    # in the new head
+    __clear_head_cache()
+    if __run('git-symbolic-ref HEAD', [ref]) != 0:
+        raise GitException, 'Could not set head to "%s"' % ref
+
 def __set_head(val):
     """Sets the HEAD value
     """
     global __head
 
-    __head = val
-    if __run('git-update-ref HEAD', [val]) != 0:
-        raise GitException, 'Could not update HEAD to "%s".' % val
+    if not __head or __head != val:
+        if __run('git-update-ref HEAD', [val]) != 0:
+            raise GitException, 'Could not update HEAD to "%s".' % val
+        __head = val
+
+def __clear_head_cache():
+    """Sets the __head to None so that a re-read is forced
+    """
+    global __head
+
+    __head = None
 
 def rev_parse(git_id):
     """Parse the string and return a verified SHA1 id
@@ -250,6 +267,73 @@ def rev_parse(git_id):
     except GitException:
         raise GitException, 'Unknown revision: %s' % git_id
 
+def branch_exists(branch):
+    """Existance check for the named branch
+    """
+    for line in _output_lines(['git-rev-parse', '--symbolic', '--all']):
+        if line.strip() == branch:
+            return True
+    return False
+
+def create_branch(new_branch, tree_id = None):
+    """Create a new branch in the git repository
+    """
+    new_head = os.path.join('refs', 'heads', new_branch)
+    if branch_exists(new_head):
+        raise GitException, 'Branch "%s" already exists' % new_branch
+
+    current_head = get_head()
+    set_head_file(new_head)
+    __set_head(current_head)
+
+    # a checkout isn't needed if new branch points to the current head
+    if tree_id:
+        switch(tree_id)
+
+    if os.path.isfile(os.path.join(base_dir, 'MERGE_HEAD')):
+        os.remove(os.path.join(base_dir, 'MERGE_HEAD'))
+
+def switch_branch(name):
+    """Switch to a git branch
+    """
+    global __head
+
+    new_head = os.path.join('refs', 'heads', name)
+    if not branch_exists(new_head):
+        raise GitException, 'Branch "%s" does not exist' % name
+
+    tree_id = rev_parse(new_head + '^0')
+    if tree_id != get_head():
+        if __run('git-read-tree -u -m', [get_head(), tree_id]) != 0:
+            raise GitException, 'git-read-tree failed (local changes maybe?)'
+        __head = tree_id
+    set_head_file(new_head)
+
+    if os.path.isfile(os.path.join(base_dir, 'MERGE_HEAD')):
+        os.remove(os.path.join(base_dir, 'MERGE_HEAD'))
+
+def delete_branch(name):
+    """Delete a git branch
+    """
+    branch_head = os.path.join('refs', 'heads', name)
+    if not branch_exists(branch_head):
+        raise GitException, 'Branch "%s" does not exist' % name
+    os.remove(os.path.join(base_dir, branch_head))
+
+def rename_branch(from_name, to_name):
+    """Rename a git branch
+    """
+    from_head = os.path.join('refs', 'heads', from_name)
+    if not branch_exists(from_head):
+        raise GitException, 'Branch "%s" does not exist' % from_name
+    to_head = os.path.join('refs', 'heads', to_name)
+    if branch_exists(to_head):
+        raise GitException, 'Branch "%s" already exists' % to_name
+
+    if get_head_file() == from_name:
+        set_head_file(to_head)
+    os.rename(os.path.join(base_dir, from_head), os.path.join(base_dir, to_head))
+
 def add(names):
     """Add the files or recursively add the directory contents
     """
@@ -507,6 +591,9 @@ def pull(repository = 'origin', refspec = None):
     """Pull changes from the remote repository. At the moment, just
     use the 'git pull' command
     """
+    # 'git pull' updates the HEAD
+    __clear_head_cache()
+
     args = [repository]
     if refspec:
         args.append(refspec)