X-Git-Url: https://git.distorted.org.uk/~mdw/stgit/blobdiff_plain/6ef533bcc52fbf933e9f428d8ea2bf690f0ad76a..7438e0983a0fb852697d7162f6a1812d7ebb0c25:/stgit/git.py

diff --git a/stgit/git.py b/stgit/git.py
index 5f3f030..1f57481 100644
--- a/stgit/git.py
+++ b/stgit/git.py
@@ -19,10 +19,12 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 """
 
 import sys, os, popen2, re, gitmergeonefile
+from shutil import copyfile
 
 from stgit import basedir
 from stgit.utils import *
 from stgit.config import config
+from sets import Set
 
 # git exception class
 class GitException(Exception):
@@ -33,13 +35,46 @@ class GitException(Exception):
 #
 # Classes
 #
+
+class Person:
+    """An author, committer, etc."""
+    def __init__(self, name = None, email = None, date = '',
+                 desc = None):
+        self.name = self.email = self.date = None
+        if name or email or date:
+            assert not desc
+            self.name = name
+            self.email = email
+            self.date = date
+        elif desc:
+            assert not (name or email or date)
+            def parse_desc(s):
+                m = re.match(r'^(.+)<(.+)>(.*)$', s)
+                assert m
+                return [x.strip() or None for x in m.groups()]
+            self.name, self.email, self.date = parse_desc(desc)
+    def set_name(self, val):
+        if val:
+            self.name = val
+    def set_email(self, val):
+        if val:
+            self.email = val
+    def set_date(self, val):
+        if val:
+            self.date = val
+    def __str__(self):
+        if self.name and self.email:
+            return '%s <%s>' % (self.name, self.email)
+        else:
+            raise GitException, 'not enough identity data'
+
 class Commit:
     """Handle the commit objects
     """
     def __init__(self, id_hash):
         self.__id_hash = id_hash
 
-        lines = _output_lines('git-cat-file commit %s' % id_hash)
+        lines = _output_lines(['git-cat-file', 'commit', id_hash])
         for i in range(len(lines)):
             line = lines[i]
             if line == '\n':
@@ -67,8 +102,8 @@ class Commit:
             return None
 
     def get_parents(self):
-        return _output_lines('git-rev-list --parents --max-count=1 %s'
-                             % self.__id_hash)[0].split()[1:]
+        return _output_lines(['git-rev-list', '--parents', '--max-count=1',
+                              self.__id_hash])[0].split()[1:]
 
     def get_author(self):
         return self.__author
@@ -123,7 +158,7 @@ def _input(cmd, file_desc):
         p.tochild.write(line)
     p.tochild.close()
     if p.wait():
-        raise GitException, '%s failed (%s)' % (str(cmd),
+        raise GitException, '%s failed (%s)' % (' '.join(cmd),
                                                 p.childerr.read().strip())
 
 def _input_str(cmd, string):
@@ -131,14 +166,14 @@ def _input_str(cmd, string):
     p.tochild.write(string)
     p.tochild.close()
     if p.wait():
-        raise GitException, '%s failed (%s)' % (str(cmd),
+        raise GitException, '%s failed (%s)' % (' '.join(cmd),
                                                 p.childerr.read().strip())
 
 def _output(cmd):
     p=popen2.Popen3(cmd, True)
     output = p.fromchild.read()
     if p.wait():
-        raise GitException, '%s failed (%s)' % (str(cmd),
+        raise GitException, '%s failed (%s)' % (' '.join(cmd),
                                                 p.childerr.read().strip())
     return output
 
@@ -150,7 +185,7 @@ def _output_one_line(cmd, file_desc = None):
         p.tochild.close()
     output = p.fromchild.readline().strip()
     if p.wait():
-        raise GitException, '%s failed (%s)' % (str(cmd),
+        raise GitException, '%s failed (%s)' % (' '.join(cmd),
                                                 p.childerr.read().strip())
     return output
 
@@ -158,7 +193,7 @@ def _output_lines(cmd):
     p=popen2.Popen3(cmd, True)
     lines = p.fromchild.readlines()
     if p.wait():
-        raise GitException, '%s failed (%s)' % (str(cmd),
+        raise GitException, '%s failed (%s)' % (' '.join(cmd),
                                                 p.childerr.read().strip())
     return lines
 
@@ -181,10 +216,13 @@ def __run(cmd, args=None):
         return r
     return 0
 
-def __tree_status(files = None, tree_id = 'HEAD', unknown = False,
-                  noexclude = True):
+def tree_status(files = None, tree_id = 'HEAD', unknown = False,
+                  noexclude = True, verbose = False, diff_flags = []):
     """Returns a list of pairs - [status, filename]
     """
+    if verbose:
+        out.start('Checking for changes in the working directory')
+
     refresh_index()
 
     if not files:
@@ -216,17 +254,21 @@ def __tree_status(files = None, tree_id = 'HEAD', unknown = False,
     cache_files += [('C', filename) for filename in conflicts]
 
     # the rest
-    for line in _output_lines(['git-diff-index', tree_id, '--'] + files):
+    for line in _output_lines(['git-diff-index'] + diff_flags +
+                              [ tree_id, '--'] + files):
         fs = tuple(line.rstrip().split(' ',4)[-1].split('\t',1))
         if fs[1] not in conflicts:
             cache_files.append(fs)
 
+    if verbose:
+        out.done()
+
     return cache_files
 
-def local_changes():
+def local_changes(verbose = True):
     """Return true if there are local changes in the tree
     """
-    return len(__tree_status()) != 0
+    return len(tree_status(verbose = verbose)) != 0
 
 # HEAD value cached
 __head = None
@@ -244,7 +286,7 @@ def get_head_file():
     """Returns the name of the file pointed to by the HEAD link
     """
     return strip_prefix('refs/heads/',
-                        _output_one_line('git-symbolic-ref HEAD'))
+                        _output_one_line(['git-symbolic-ref', 'HEAD']))
 
 def set_head_file(ref):
     """Resets HEAD to point to a new ref
@@ -256,14 +298,18 @@ def set_head_file(ref):
              [os.path.join('refs', 'heads', ref)]) != 0:
         raise GitException, 'Could not set head to "%s"' % ref
 
+def set_branch(branch, val):
+    """Point branch at a new commit object."""
+    if __run('git-update-ref', [branch, val]) != 0:
+        raise GitException, 'Could not update %s to "%s".' % (branch, val)
+
 def __set_head(val):
     """Sets the HEAD value
     """
     global __head
 
     if not __head or __head != val:
-        if __run('git-update-ref HEAD', [val]) != 0:
-            raise GitException, 'Could not update HEAD to "%s".' % val
+        set_branch('HEAD', val)
         __head = val
 
     # only allow SHA1 hashes
@@ -358,6 +404,11 @@ def rename_branch(from_name, to_name):
     rename(os.path.join(basedir.get(), 'refs', 'heads'),
            from_name, to_name)
 
+    reflog_dir = os.path.join(basedir.get(), 'logs', 'refs', 'heads')
+    if os.path.exists(reflog_dir) \
+           and os.path.exists(os.path.join(reflog_dir, from_name)):
+        rename(reflog_dir, from_name, to_name)
+
 def add(names):
     """Add the files or recursively add the directory contents
     """
@@ -382,6 +433,70 @@ def add(names):
         if __run('git-update-index --add --', files):
             raise GitException, 'Unable to add file'
 
+def __copy_single(source, target, target2=''):
+    """Copy file or dir named 'source' to name target+target2"""
+
+    # "source" (file or dir) must match one or more git-controlled file
+    realfiles = _output_lines(['git-ls-files', source])
+    if len(realfiles) == 0:
+        raise GitException, '"%s" matches no git-controled files' % source
+
+    if os.path.isdir(source):
+        # physically copy the files, and record them to add them in one run
+        newfiles = []
+        re_string='^'+source+'/(.*)$'
+        prefix_regexp = re.compile(re_string)
+        for f in [f.strip() for f in realfiles]:
+            m = prefix_regexp.match(f)
+            if not m:
+                raise Exception, '"%s" does not match "%s"' % (f, re_string)
+            newname = target+target2+'/'+m.group(1)
+            if not os.path.exists(os.path.dirname(newname)):
+                os.makedirs(os.path.dirname(newname))
+            copyfile(f, newname)
+            newfiles.append(newname)
+
+        add(newfiles)
+    else: # files, symlinks, ...
+        newname = target+target2
+        copyfile(source, newname)
+        add([newname])
+
+
+def copy(filespecs, target):
+    if os.path.isdir(target):
+        # target is a directory: copy each entry on the command line,
+        # with the same name, into the target
+        target = target.rstrip('/')
+        
+        # first, check that none of the children of the target
+        # matching the command line aleady exist
+        for filespec in filespecs:
+            entry = target+ '/' + os.path.basename(filespec.rstrip('/'))
+            if os.path.exists(entry):
+                raise GitException, 'Target "%s" already exists' % entry
+        
+        for filespec in filespecs:
+            filespec = filespec.rstrip('/')
+            basename = '/' + os.path.basename(filespec)
+            __copy_single(filespec, target, basename)
+
+    elif os.path.exists(target):
+        raise GitException, 'Target "%s" exists but is not a directory' % target
+    elif len(filespecs) != 1:
+        raise GitException, 'Cannot copy more than one file to non-directory'
+
+    else:
+        # at this point: len(filespecs)==1 and target does not exist
+
+        # check target directory
+        targetdir = os.path.dirname(target)
+        if targetdir != '' and not os.path.isdir(targetdir):
+            raise GitException, 'Target directory "%s" does not exist' % targetdir
+
+        __copy_single(filespecs[0].rstrip('/'), target)
+        
+
 def rm(files, force = False):
     """Remove a file from the repository
     """
@@ -395,13 +510,64 @@ def rm(files, force = False):
         if files:
             __run('git-update-index --force-remove --', files)
 
+# Persons caching
+__user = None
+__author = None
+__committer = None
+
+def user():
+    """Return the user information.
+    """
+    global __user
+    if not __user:
+        name=config.get('user.name')
+        email=config.get('user.email')
+        __user = Person(name, email)
+    return __user;
+
+def author():
+    """Return the author information.
+    """
+    global __author
+    if not __author:
+        try:
+            # the environment variables take priority over config
+            try:
+                date = os.environ['GIT_AUTHOR_DATE']
+            except KeyError:
+                date = ''
+            __author = Person(os.environ['GIT_AUTHOR_NAME'],
+                              os.environ['GIT_AUTHOR_EMAIL'],
+                              date)
+        except KeyError:
+            __author = user()
+    return __author
+
+def committer():
+    """Return the author information.
+    """
+    global __committer
+    if not __committer:
+        try:
+            # the environment variables take priority over config
+            try:
+                date = os.environ['GIT_COMMITTER_DATE']
+            except KeyError:
+                date = ''
+            __committer = Person(os.environ['GIT_COMMITTER_NAME'],
+                                 os.environ['GIT_COMMITTER_EMAIL'],
+                                 date)
+        except KeyError:
+            __committer = user()
+    return __committer
+
 def update_cache(files = None, force = False):
     """Update the cache information for the given files
     """
     if not files:
         files = []
 
-    cache_files = __tree_status(files)
+    cache_files = tree_status(files, verbose = False)
 
     # everything is up-to-date
     if len(cache_files) == 0:
@@ -452,27 +618,27 @@ def commit(message, files = None, parents = None, allowempty = False,
     must_switch = True
     # write the index to repository
     if tree_id == None:
-        tree_id = _output_one_line('git-write-tree')
+        tree_id = _output_one_line(['git-write-tree'])
     else:
         must_switch = False
 
     # the commit
-    cmd = ''
+    cmd = ['env']
     if author_name:
-        cmd += 'GIT_AUTHOR_NAME="%s" ' % author_name
+        cmd += ['GIT_AUTHOR_NAME=%s' % author_name]
     if author_email:
-        cmd += 'GIT_AUTHOR_EMAIL="%s" ' % author_email
+        cmd += ['GIT_AUTHOR_EMAIL=%s' % author_email]
     if author_date:
-        cmd += 'GIT_AUTHOR_DATE="%s" ' % author_date
+        cmd += ['GIT_AUTHOR_DATE=%s' % author_date]
     if committer_name:
-        cmd += 'GIT_COMMITTER_NAME="%s" ' % committer_name
+        cmd += ['GIT_COMMITTER_NAME=%s' % committer_name]
     if committer_email:
-        cmd += 'GIT_COMMITTER_EMAIL="%s" ' % committer_email
-    cmd += 'git-commit-tree %s' % tree_id
+        cmd += ['GIT_COMMITTER_EMAIL=%s' % committer_email]
+    cmd += ['git-commit-tree', tree_id]
 
     # get the parents
     for p in parents:
-        cmd += ' -p %s' % p
+        cmd += ['-p', p]
 
     commit_id = _output_one_line(cmd, message)
     if must_switch:
@@ -487,9 +653,9 @@ def apply_diff(rev1, rev2, check_index = True, files = None):
     the pushing would fall back to the three-way merge.
     """
     if check_index:
-        index_opt = '--index'
+        index_opt = ['--index']
     else:
-        index_opt = ''
+        index_opt = []
 
     if not files:
         files = []
@@ -497,25 +663,41 @@ def apply_diff(rev1, rev2, check_index = True, files = None):
     diff_str = diff(files, rev1, rev2)
     if diff_str:
         try:
-            _input_str('git-apply %s' % index_opt, diff_str)
+            _input_str(['git-apply'] + index_opt, diff_str)
         except GitException:
             return False
 
     return True
 
-def merge(base, head1, head2):
+def merge(base, head1, head2, recursive = False):
     """Perform a 3-way merge between base, head1 and head2 into the
     local tree
     """
     refresh_index()
-    if __run('git-read-tree -u -m --aggressive', [base, head1, head2]) != 0:
-        raise GitException, 'git-read-tree failed (local changes maybe?)'
+
+    err_output = None
+    if recursive:
+        # this operation tracks renames but it is slower (used in
+        # general when pushing or picking patches)
+        try:
+            # use _output() to mask the verbose prints of the tool
+            _output(['git-merge-recursive', base, '--', head1, head2])
+        except GitException, ex:
+            err_output = str(ex)
+            pass
+    else:
+        # the fast case where we don't track renames (used when the
+        # distance between base and heads is small, i.e. folding or
+        # synchronising patches)
+        if __run('git-read-tree -u -m --aggressive',
+                 [base, head1, head2]) != 0:
+            raise GitException, 'git-read-tree failed (local changes maybe?)'
 
     # check the index for unmerged entries
     files = {}
     stages_re = re.compile('^([0-7]+) ([0-9a-f]{40}) ([1-3])\t(.*)$', re.S)
 
-    for line in _output('git-ls-files --unmerged --stage -z').split('\0'):
+    for line in _output(['git-ls-files', '--unmerged', '--stage', '-z']).split('\0'):
         if not line:
             continue
 
@@ -529,9 +711,23 @@ def merge(base, head1, head2):
 
         files[path][stage] = (mode, hash)
 
+    if err_output and not files:
+        # if no unmerged files, there was probably a different type of
+        # error and we have to abort the merge
+        raise GitException, err_output
+
     # merge the unmerged files
     errors = False
     for path in files:
+        # remove additional files that might be generated for some
+        # newer versions of GIT
+        for suffix in [base, head1, head2]:
+            if not suffix:
+                continue
+            fname = path + '~' + suffix
+            if os.path.exists(fname):
+                os.remove(fname)
+
         stages = files[path]
         if gitmergeonefile.merge(stages['1'][1], stages['2'][1],
                                  stages['3'][1], path, stages['1'][0],
@@ -542,13 +738,15 @@ def merge(base, head1, head2):
         raise GitException, 'GIT index merging failed (possible conflicts)'
 
 def status(files = None, modified = False, new = False, deleted = False,
-           conflict = False, unknown = False, noexclude = False):
+           conflict = False, unknown = False, noexclude = False,
+           diff_flags = []):
     """Show the tree status
     """
     if not files:
         files = []
 
-    cache_files = __tree_status(files, unknown = True, noexclude = noexclude)
+    cache_files = tree_status(files, unknown = True, noexclude = noexclude,
+                                diff_flags = diff_flags)
     all = not (modified or new or deleted or conflict or unknown)
 
     if not all:
@@ -567,25 +765,31 @@ def status(files = None, modified = False, new = False, deleted = False,
         cache_files = [x for x in cache_files if x[0] in filestat]
 
     for fs in cache_files:
+        if files and not fs[1] in files:
+            continue
         if all:
-            print '%s %s' % (fs[0], fs[1])
+            out.stdout('%s %s' % (fs[0], fs[1]))
         else:
-            print '%s' % fs[1]
+            out.stdout('%s' % fs[1])
 
-def diff(files = None, rev1 = 'HEAD', rev2 = None, out_fd = None):
+def diff(files = None, rev1 = 'HEAD', rev2 = None, out_fd = None,
+         diff_flags = []):
     """Show the diff between rev1 and rev2
     """
     if not files:
         files = []
 
     if rev1 and rev2:
-        diff_str = _output(['git-diff-tree', '-p', rev1, rev2, '--'] + files)
+        diff_str = _output(['git-diff-tree', '-p'] + diff_flags
+                           + [rev1, rev2, '--'] + files)
     elif rev1 or rev2:
         refresh_index()
         if rev2:
-            diff_str = _output(['git-diff-index', '-p', '-R', rev2, '--'] + files)
+            diff_str = _output(['git-diff-index', '-p', '-R']
+                               + diff_flags + [rev2, '--'] + files)
         else:
-            diff_str = _output(['git-diff-index', '-p', rev1, '--'] + files)
+            diff_str = _output(['git-diff-index', '-p']
+                               + diff_flags + [rev1, '--'] + files)
     else:
         diff_str = ''
 
@@ -608,12 +812,12 @@ def diffstat(files = None, rev1 = 'HEAD', rev2 = None):
         raise GitException, 'git.diffstat failed'
     return diff_str
 
-def files(rev1, rev2):
+def files(rev1, rev2, diff_flags = []):
     """Return the files modified between rev1 and rev2
     """
 
     result = ''
-    for line in _output_lines('git-diff-tree -r %s %s' % (rev1, rev2)):
+    for line in _output_lines(['git-diff-tree'] + diff_flags + ['-r', rev1, rev2]):
         result += '%s %s\n' % tuple(line.rstrip().split(' ',4)[-1].split('\t',1))
 
     return result.rstrip()
@@ -623,16 +827,16 @@ def barefiles(rev1, rev2):
     """
 
     result = ''
-    for line in _output_lines('git-diff-tree -r %s %s' % (rev1, rev2)):
+    for line in _output_lines(['git-diff-tree', '-r', rev1, rev2]):
         result += '%s\n' % line.rstrip().split(' ',4)[-1].split('\t',1)[-1]
 
     return result.rstrip()
 
-def pretty_commit(commit_id = 'HEAD'):
+def pretty_commit(commit_id = 'HEAD', diff_flags = []):
     """Return a given commit (log + diff)
     """
-    return _output(['git-diff-tree', '--cc', '--always', '--pretty', '-r',
-                    commit_id])
+    return _output(['git-diff-tree'] + diff_flags +
+                   ['--cc', '--always', '--pretty', '-r', commit_id])
 
 def checkout(files = None, tree_id = None, force = False):
     """Check out the given or all files
@@ -672,7 +876,7 @@ def reset(files = None, tree_id = None, check_out = True):
         tree_id = get_head()
 
     if check_out:
-        cache_files = __tree_status(files, tree_id)
+        cache_files = tree_status(files, tree_id)
         # files which were added but need to be removed
         rm_files =  [x[1] for x in cache_files if x[0] in ['A']]
 
@@ -684,47 +888,78 @@ def reset(files = None, tree_id = None, check_out = True):
     if not files:
         __set_head(tree_id)
 
+def fetch(repository = 'origin', refspec = None):
+    """Fetches changes from the remote repository, using 'git-fetch'
+    by default.
+    """
+    # we update the HEAD
+    __clear_head_cache()
+
+    args = [repository]
+    if refspec:
+        args.append(refspec)
+
+    command = config.get('branch.%s.stgit.fetchcmd' % get_head_file()) or \
+              config.get('stgit.fetchcmd')
+    if __run(command, args) != 0:
+        raise GitException, 'Failed "%s %s"' % (command, repository)
+
 def pull(repository = 'origin', refspec = None):
-    """Pull changes from the remote repository. At the moment, just
-    use the 'git-pull' command
+    """Fetches changes from the remote repository, using 'git-pull'
+    by default.
     """
-    # 'git-pull' updates the HEAD
+    # we update the HEAD
     __clear_head_cache()
 
     args = [repository]
     if refspec:
         args.append(refspec)
 
-    if __run(config.get('stgit', 'pullcmd'), args) != 0:
-        raise GitException, 'Failed "git-pull %s"' % repository
+    command = config.get('branch.%s.stgit.pullcmd' % get_head_file()) or \
+              config.get('stgit.pullcmd')
+    if __run(command, args) != 0:
+        raise GitException, 'Failed "%s %s"' % (command, repository)
 
-def apply_patch(filename = None, diff = None, base = None):
+def repack():
+    """Repack all objects into a single pack
+    """
+    __run('git-repack -a -d -f')
+
+def apply_patch(filename = None, diff = None, base = None,
+                fail_dump = True):
     """Apply a patch onto the current or given index. There must not
     be any local changes in the tree, otherwise the command fails
     """
-    def __apply_patch():
-        try:
-            if filename:
-                return __run('git-apply --index', [filename]) == 0
-            elif diff:
-                _input_str('git-apply --index', diff)
-            else:
-                _input('git-apply --index', sys.stdin)
-        except GitException:
-            return False
-        return True
+    if diff is None:
+        if filename:
+            f = file(filename)
+        else:
+            f = sys.stdin
+        diff = f.read()
+        if filename:
+            f.close()
 
     if base:
         orig_head = get_head()
         switch(base)
     else:
-        refresh_index()         # needed since __apply_patch() doesn't do it
+        refresh_index()
 
-    if not __apply_patch():
+    try:
+        _input_str(['git-apply', '--index'], diff)
+    except GitException:
         if base:
             switch(orig_head)
-        raise GitException, 'Patch does not apply cleanly'
-    elif base:
+        if fail_dump:
+            # write the failed diff to a file
+            f = file('.stgit-failed.patch', 'w+')
+            f.write(diff)
+            f.close()
+            out.warn('Diff written to the .stgit-failed.patch file')
+
+        raise
+
+    if base:
         top = commit(message = 'temporary commit used for applying a patch',
                      parents = [base])
         switch(orig_head)
@@ -738,10 +973,106 @@ def clone(repository, local_dir):
         raise GitException, 'Failed "git-clone %s %s"' \
               % (repository, local_dir)
 
-def modifying_revs(files, base_rev):
+def modifying_revs(files, base_rev, head_rev):
     """Return the revisions from the list modifying the given files
     """
-    cmd = ['git-rev-list', '%s..' % base_rev, '--']
+    cmd = ['git-rev-list', '%s..%s' % (base_rev, head_rev), '--']
     revs = [line.strip() for line in _output_lines(cmd + files)]
 
     return revs
+
+
+def refspec_localpart(refspec):
+    m = re.match('^[^:]*:([^:]*)$', refspec)
+    if m:
+        return m.group(1)
+    else:
+        raise GitException, 'Cannot parse refspec "%s"' % line
+
+def refspec_remotepart(refspec):
+    m = re.match('^([^:]*):[^:]*$', refspec)
+    if m:
+        return m.group(1)
+    else:
+        raise GitException, 'Cannot parse refspec "%s"' % line
+    
+
+def __remotes_from_config():
+    return config.sections_matching(r'remote\.(.*)\.url')
+
+def __remotes_from_dir(dir):
+    d = os.path.join(basedir.get(), dir)
+    if os.path.exists(d):
+        return os.listdir(d)
+    else:
+        return None
+
+def remotes_list():
+    """Return the list of remotes in the repository
+    """
+
+    return Set(__remotes_from_config()) | \
+           Set(__remotes_from_dir('remotes')) | \
+           Set(__remotes_from_dir('branches'))
+
+def remotes_local_branches(remote):
+    """Returns the list of local branches fetched from given remote
+    """
+
+    branches = []
+    if remote in __remotes_from_config():
+        for line in config.getall('remote.%s.fetch' % remote):
+            branches.append(refspec_localpart(line))
+    elif remote in __remotes_from_dir('remotes'):
+        stream = open(os.path.join(basedir.get(), 'remotes', remote), 'r')
+        for line in stream:
+            # Only consider Pull lines
+            m = re.match('^Pull: (.*)\n$', line)
+            if m:
+                branches.append(refspec_localpart(m.group(1)))
+        stream.close()
+    elif remote in __remotes_from_dir('branches'):
+        # old-style branches only declare one branch
+        branches.append('refs/heads/'+remote);
+    else:
+        raise GitException, 'Unknown remote "%s"' % remote
+
+    return branches
+
+def identify_remote(branchname):
+    """Return the name for the remote to pull the given branchname
+    from, or None if we believe it is a local branch.
+    """
+
+    for remote in remotes_list():
+        if branchname in remotes_local_branches(remote):
+            return remote
+
+    # if we get here we've found nothing, the branch is a local one
+    return None
+
+def fetch_head():
+    """Return the git id for the tip of the parent branch as left by
+    'git fetch'.
+    """
+
+    fetch_head=None
+    stream = open(os.path.join(basedir.get(), 'FETCH_HEAD'), "r")
+    for line in stream:
+        # Only consider lines not tagged not-for-merge
+        m = re.match('^([^\t]*)\t\t', line)
+        if m:
+            if fetch_head:
+                raise GitException, "StGit does not support multiple FETCH_HEAD"
+            else:
+                fetch_head=m.group(1)
+    stream.close()
+
+    # here we are sure to have a single fetch_head
+    return fetch_head
+
+def all_refs():
+    """Return a list of all refs in the current repository.
+    """
+
+    return [line.split()[1] for line in _output_lines(['git-show-ref'])]