Merge branch 'stable'

[stgit] / stgit / git.py

diff --git a/stgit/git.py b/stgit/git.py
index bdc0e14f4fd764c293625453c4881babde853d66..ee31ecd07a5a7d17d1a9bba364658e97c0cdaedc 100644 (file)
--- a/stgit/git.py
+++ b/stgit/git.py
@@ -18,47 +18,88 @@ along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 """
 
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 """
 

-import sys, os, glob, popen2
+import sys, os, re, gitmergeonefile
+from shutil import copyfile

 
 

+from stgit.exception import *
+from stgit import basedir

 from stgit.utils import *
 from stgit.utils import *

+from stgit.out import *
+from stgit.run import *
+from stgit.config import config

 
 # git exception class
 
 # git exception class

-class GitException(Exception):
+class GitException(StgException):

     pass
 
     pass
 

-
-# Different start-up variables read from the environment
-if 'GIT_DIR' in os.environ:
-    base_dir = os.environ['GIT_DIR']
-else:
-    base_dir = '.git'
-
-head_link = os.path.join(base_dir, 'HEAD')
+# When a subprocess has a problem, we want the exception to be a
+# subclass of GitException.
+class GitRunException(GitException):
+    pass
+class GRun(Run):
+    exc = GitRunException
+    def __init__(self, *cmd):
+        """Initialise the Run object and insert the 'git' command name.
+        """
+        Run.__init__(self, 'git', *cmd)

 
 #
 # Classes
 #
 
 #
 # 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
 
 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 = GRun('cat-file', 'commit', id_hash).output_lines()

         for i in range(len(lines)):
             line = lines[i]
         for i in range(len(lines)):
             line = lines[i]

-            if line == '\n':
-                break
-            field = line.strip().split(' ', 1)
-            if field[0] == 'tree':
-                self.__tree = field[1]
-            elif field[0] == 'parent':
-                self.__parent = field[1]
-            if field[0] == 'author':
-                self.__author = field[1]
-            if field[0] == 'comitter':
-                self.__committer = field[1]
-        self.__log = ''.join(lines[i:])
+            if not line:
+                break # we've seen all the header fields
+            key, val = line.split(' ', 1)
+            if key == 'tree':
+                self.__tree = val
+            elif key == 'author':
+                self.__author = val
+            elif key == 'committer':
+                self.__committer = val
+            else:
+                pass # ignore other headers
+        self.__log = '\n'.join(lines[i+1:])

 
     def get_id_hash(self):
         return self.__id_hash
 
     def get_id_hash(self):
         return self.__id_hash


@@ -67,7 +108,15 @@ class Commit:
         return self.__tree
 
     def get_parent(self):
         return self.__tree
 
     def get_parent(self):

-        return self.__parent
+        parents = self.get_parents()
+        if parents:
+            return parents[0]
+        else:
+            return None
+
+    def get_parents(self):
+        return GRun('rev-list', '--parents', '--max-count=1', self.__id_hash
+                    ).output_one_line().split()[1:]

 
     def get_author(self):
         return self.__author
 
     def get_author(self):
         return self.__author


@@ -75,16 +124,25 @@ class Commit:
     def get_committer(self):
         return self.__committer
 
     def get_committer(self):
         return self.__committer
 

+    def get_log(self):
+        return self.__log
+
+    def __str__(self):
+        return self.get_id_hash()
+

 # dictionary of Commit objects, used to avoid multiple calls to git
 __commits = dict()
 
 #
 # Functions
 #
 # dictionary of Commit objects, used to avoid multiple calls to git
 __commits = dict()
 
 #
 # Functions
 #

+

 def get_commit(id_hash):
     """Commit objects factory. Save/look-up them in the __commits
     dictionary
     """
 def get_commit(id_hash):
     """Commit objects factory. Save/look-up them in the __commits
     dictionary
     """

+    global __commits
+

     if id_hash in __commits:
         return __commits[id_hash]
     else:
     if id_hash in __commits:
         return __commits[id_hash]
     else:


@@ -95,176 +153,380 @@ def get_commit(id_hash):
 def get_conflicts():
     """Return the list of file conflicts
     """
 def get_conflicts():
     """Return the list of file conflicts
     """

-    conflicts_file = os.path.join(base_dir, 'conflicts')
-    if os.path.isfile(conflicts_file):
-        f = file(conflicts_file)
-        names = [line.strip() for line in f.readlines()]
-        f.close()
-        return names
-    else:
-        return None
-
-def _input(cmd, file_desc):
-    p = popen2.Popen3(cmd)
-    for line in file_desc:
-        p.tochild.write(line)
-    p.tochild.close()
-    if p.wait():
-        raise GitException, '%s failed' % str(cmd)
-
-def _output(cmd):
-    p=popen2.Popen3(cmd)
-    string = p.fromchild.read()
-    if p.wait():
-        raise GitException, '%s failed' % str(cmd)
-    return string
-
-def _output_one_line(cmd):
-    p=popen2.Popen3(cmd)
-    string = p.fromchild.readline().strip()
-    if p.wait():
-        raise GitException, '%s failed' % str(cmd)
-    return string
-
-def _output_lines(cmd):
-    p=popen2.Popen3(cmd)
-    lines = p.fromchild.readlines()
-    if p.wait():
-        raise GitException, '%s failed' % str(cmd)
-    return lines
-
-def __run(cmd, args=None):
-    """__run: runs cmd using spawnvp.
-
-    Runs cmd using spawnvp.  The shell is avoided so it won't mess up
-    our arguments.  If args is very large, the command is run multiple
-    times; args is split xargs style: cmd is passed on each
-    invocation.  Unlike xargs, returns immediately if any non-zero
-    return code is received.  
-    """
-    
-    args_l=cmd.split()
-    if args is None:
-        args = []
-    for i in range(0, len(args)+1, 100):
-        r=os.spawnvp(os.P_WAIT, args_l[0], args_l + args[i:min(i+100, len(args))])
-    if r:
-        return r
-    return 0
+    names = set()
+    for line in GRun('ls-files', '-z', '--unmerged'
+                     ).raw_output().split('\0')[:-1]:
+        stat, path = line.split('\t', 1)
+        names.add(path)
+    return list(names)
+
+def exclude_files():
+    files = [os.path.join(basedir.get(), 'info', 'exclude')]
+    user_exclude = config.get('core.excludesfile')
+    if user_exclude:
+        files.append(user_exclude)
+    return files
+
+def ls_files(files, tree = 'HEAD', full_name = True):
+    """Return the files known to GIT or raise an error otherwise. It also
+    converts the file to the full path relative the the .git directory.
+    """
+    if not files:
+        return []
+
+    args = []
+    if tree:
+        args.append('--with-tree=%s' % tree)
+    if full_name:
+        args.append('--full-name')
+    args.append('--')
+    args.extend(files)
+    try:
+        # use a set to avoid file names duplication due to different stages
+        fileset = set(GRun('ls-files', '--error-unmatch', *args).output_lines())
+    except GitRunException:
+        # just hide the details of the 'git ls-files' command we use
+        raise GitException, \
+            'Some of the given paths are either missing or not known to GIT'
+    return list(fileset)
+
+def parse_git_ls(output):
+    """Parse the output of git diff-index, diff-files, etc. Doesn't handle
+    rename/copy output, so don't feed it output generated with the -M
+    or -C flags."""
+    t = None
+    for line in output.split('\0'):
+        if not line:
+            # There's a zero byte at the end of the output, which
+            # gives us an empty string as the last "line".
+            continue
+        if t == None:
+            mode_a, mode_b, sha1_a, sha1_b, t = line.split(' ')
+        else:
+            yield (t, line)
+            t = None

 
 

-def __check_base_dir():
-    return os.path.isdir(base_dir)
+def tree_status(files = None, tree_id = 'HEAD', unknown = False,
+                  noexclude = True, verbose = False):
+    """Get the status of all changed files, or of a selected set of
+    files. Returns a list of pairs - (status, filename).

 
 

-def __tree_status(files = [], tree_id = 'HEAD', unknown = False,
-                  noexclude = True):
-    """Returns a list of pairs - [status, filename]
+    If 'not files', it will check all files, and optionally all
+    unknown files.  If 'files' is a list, it will only check the files
+    in the list.

     """
     """

-    os.system('git-update-cache --refresh > /dev/null')
+    assert not files or not unknown
+
+    if verbose:
+        out.start('Checking for changes in the working directory')
+
+    refresh_index()

 
 

+    if files is None:
+        files = []

     cache_files = []
 
     # unknown files
     if unknown:
     cache_files = []
 
     # unknown files
     if unknown:

-        exclude_file = os.path.join(base_dir, 'info', 'exclude')
-        base_exclude = ['--exclude=%s' % s for s in
-                        ['*.[ao]', '*.pyc', '.*', '*~', '#*', 'TAGS', 'tags']]
-        base_exclude.append('--exclude-per-directory=.gitignore')
-
-        if os.path.exists(exclude_file):
-            extra_exclude = '--exclude-from=%s' % exclude_file
-        else:
-            extra_exclude = []
-        if noexclude:
-            extra_exclude = base_exclude = []
-
-        lines = _output_lines(['git-ls-files', '--others'] + base_exclude
-                        + extra_exclude)
-        cache_files += [('?', line.strip()) for line in lines]
+        cmd = ['ls-files', '-z', '--others', '--directory',
+               '--no-empty-directory']
+        if not noexclude:
+            cmd += ['--exclude=%s' % s for s in
+                    ['*.[ao]', '*.pyc', '.*', '*~', '#*', 'TAGS', 'tags']]
+            cmd += ['--exclude-per-directory=.gitignore']
+            cmd += ['--exclude-from=%s' % fn
+                    for fn in exclude_files()
+                    if os.path.exists(fn)]
+
+        lines = GRun(*cmd).raw_output().split('\0')
+        cache_files += [('?', line) for line in lines if line]

 
     # conflicted files
     conflicts = get_conflicts()
 
     # conflicted files
     conflicts = get_conflicts()

-    if not conflicts:
-        conflicts = []
-    cache_files += [('C', filename) for filename in conflicts]
-
-    # the rest
-    for line in _output_lines(['git-diff-cache', '-r', tree_id] + files):
-        fs = tuple(line.rstrip().split(' ',4)[-1].split('\t',1))
-        if fs[1] not in conflicts:
-            cache_files.append(fs)
+    cache_files += [('C', filename) for filename in conflicts
+                    if not files or filename in files]
+    reported_files = set(conflicts)
+    files_left = [f for f in files if f not in reported_files]
+
+    # files in the index. Only execute this code if no files were
+    # specified when calling the function (i.e. report all files) or
+    # files were specified but already found in the previous step
+    if not files or files_left:
+        args = [tree_id]
+        if files_left:
+            args += ['--'] + files_left
+        for t, fn in parse_git_ls(GRun('diff-index', '-z', *args).raw_output()):
+            # the condition is needed in case files is emtpy and
+            # diff-index lists those already reported
+            if not fn in reported_files:
+                cache_files.append((t, fn))
+                reported_files.add(fn)
+        files_left = [f for f in files if f not in reported_files]
+
+    # files in the index but changed on (or removed from) disk. Only
+    # execute this code if no files were specified when calling the
+    # function (i.e. report all files) or files were specified but
+    # already found in the previous step
+    if not files or files_left:
+        args = []
+        if files_left:
+            args += ['--'] + files_left
+        for t, fn in parse_git_ls(GRun('diff-files', '-z', *args).raw_output()):
+            # the condition is needed in case files is empty and
+            # diff-files lists those already reported
+            if not fn in reported_files:
+                cache_files.append((t, fn))
+                reported_files.add(fn)
+
+    if verbose:
+        out.done()

 
     return cache_files
 
 
     return cache_files
 

-def local_changes():
+def local_changes(verbose = True):

     """Return true if there are local changes in the tree
     """
     """Return true if there are local changes in the tree
     """

-    return len(__tree_status()) != 0
+    return len(tree_status(verbose = verbose)) != 0
+
+def get_heads():
+    heads = []
+    hr = re.compile(r'^[0-9a-f]{40} refs/heads/(.+)$')
+    for line in GRun('show-ref', '--heads').output_lines():
+        m = hr.match(line)
+        heads.append(m.group(1))
+    return heads
+
+# HEAD value cached
+__head = None

 
 def get_head():
 
 def get_head():

-    """Returns a string representing the HEAD
+    """Verifies the HEAD and returns the SHA1 id that represents it

     """
     """

-    return read_string(head_link)
+    global __head
+
+    if not __head:
+        __head = rev_parse('HEAD')
+    return __head
+
+class DetachedHeadException(GitException):
+    def __init__(self):
+        GitException.__init__(self, 'Not on any branch')

 
 def get_head_file():
 
 def get_head_file():

-    """Returns the name of the file pointed to by the HEAD link
+    """Return the name of the file pointed to by the HEAD symref.
+    Throw an exception if HEAD is detached."""
+    try:
+        return strip_prefix(
+            'refs/heads/', GRun('symbolic-ref', '-q', 'HEAD'
+                                ).output_one_line())
+    except GitRunException:
+        raise DetachedHeadException()
+
+def set_head_file(ref):
+    """Resets HEAD to point to a new ref

     """
     """

-    # valid link
-    if os.path.islink(head_link) and os.path.isfile(head_link):
-        return os.path.basename(os.readlink(head_link))
-    else:
-        raise GitException, 'Invalid .git/HEAD link. Git tree not initialised?'
+    # head cache flushing is needed since we might have a different value
+    # in the new head
+    __clear_head_cache()
+    try:
+        GRun('symbolic-ref', 'HEAD', 'refs/heads/%s' % ref).run()
+    except GitRunException:
+        raise GitException, 'Could not set head to "%s"' % ref
+
+def set_ref(ref, val):
+    """Point ref at a new commit object."""
+    try:
+        GRun('update-ref', ref, val).run()
+    except GitRunException:
+        raise GitException, 'Could not update %s to "%s".' % (ref, val)
+
+def set_branch(branch, val):
+    set_ref('refs/heads/%s' % branch, val)

 
 def __set_head(val):
     """Sets the HEAD value
     """
 
 def __set_head(val):
     """Sets the HEAD value
     """

-    write_string(head_link, val)
-
-def add(names):
-    """Add the files or recursively add the directory contents
-    """
-    # generate the file list
-    files = []
-    for i in names:
-        if not os.path.exists(i):
-            raise GitException, 'Unknown file or directory: %s' % i
-
-        if os.path.isdir(i):
-            # recursive search. We only add files
-            for root, dirs, local_files in os.walk(i):
-                for name in [os.path.join(root, f) for f in local_files]:
-                    if os.path.isfile(name):
-                        files.append(os.path.normpath(name))
-        elif os.path.isfile(i):
-            files.append(os.path.normpath(i))
-        else:
-            raise GitException, '%s is not a file or directory' % i
+    global __head

 
 

-    if files:
-        if __run('git-update-cache --add --', files):
-            raise GitException, 'Unable to add file'
+    if not __head or __head != val:
+        set_ref('HEAD', val)
+        __head = val
+
+    # only allow SHA1 hashes
+    assert(len(__head) == 40)

 
 

-def rm(files, force = False):
-    """Remove a file from the repository
+def __clear_head_cache():
+    """Sets the __head to None so that a re-read is forced

     """
     """

-    if force:
-        git_opt = '--force-remove'
-    else:
-        git_opt = '--remove'
-
-    if not force:
-        for f in files:
-            if os.path.exists(f):
-                raise GitException, '%s exists. Remove it first' %f
-        if files:
-            __run('git-update-cache --remove --', files)
-    else:
-        if files:
-            __run('git-update-cache --force-remove --', files)
+    global __head
+
+    __head = None
+
+def refresh_index():
+    """Refresh index with stat() information from the working directory.
+    """
+    GRun('update-index', '-q', '--unmerged', '--refresh').run()
+
+def rev_parse(git_id):
+    """Parse the string and return a verified SHA1 id
+    """
+    try:
+        return GRun('rev-parse', '--verify', git_id
+                    ).discard_stderr().output_one_line()
+    except GitRunException:
+        raise GitException, 'Unknown revision: %s' % git_id
+
+def ref_exists(ref):
+    try:
+        rev_parse(ref)
+        return True
+    except GitException:
+        return False

 
 

-def update_cache(files = [], force = False):
+def branch_exists(branch):
+    return ref_exists('refs/heads/%s' % branch)
+
+def create_branch(new_branch, tree_id = None):
+    """Create a new branch in the git repository
+    """
+    if branch_exists(new_branch):
+        raise GitException, 'Branch "%s" already exists' % new_branch
+
+    current_head_file = get_head_file()
+    current_head = get_head()
+    set_head_file(new_branch)
+    __set_head(current_head)
+
+    # a checkout isn't needed if new branch points to the current head
+    if tree_id:
+        try:
+            switch(tree_id)
+        except GitException:
+            # Tree switching failed. Revert the head file
+            set_head_file(current_head_file)
+            delete_branch(new_branch)
+            raise
+
+    if os.path.isfile(os.path.join(basedir.get(), 'MERGE_HEAD')):
+        os.remove(os.path.join(basedir.get(), 'MERGE_HEAD'))
+
+def switch_branch(new_branch):
+    """Switch to a git branch
+    """
+    global __head
+
+    if not branch_exists(new_branch):
+        raise GitException, 'Branch "%s" does not exist' % new_branch
+
+    tree_id = rev_parse('refs/heads/%s^{commit}' % new_branch)
+    if tree_id != get_head():
+        refresh_index()
+        try:
+            GRun('read-tree', '-u', '-m', get_head(), tree_id).run()
+        except GitRunException:
+            raise GitException, 'read-tree failed (local changes maybe?)'
+        __head = tree_id
+    set_head_file(new_branch)
+
+    if os.path.isfile(os.path.join(basedir.get(), 'MERGE_HEAD')):
+        os.remove(os.path.join(basedir.get(), 'MERGE_HEAD'))
+
+def delete_ref(ref):
+    if not ref_exists(ref):
+        raise GitException, '%s does not exist' % ref
+    sha1 = GRun('show-ref', '-s', ref).output_one_line()
+    try:
+        GRun('update-ref', '-d', ref, sha1).run()
+    except GitRunException:
+        raise GitException, 'Failed to delete ref %s' % ref
+
+def delete_branch(name):
+    delete_ref('refs/heads/%s' % name)
+
+def rename_ref(from_ref, to_ref):
+    if not ref_exists(from_ref):
+        raise GitException, '"%s" does not exist' % from_ref
+    if ref_exists(to_ref):
+        raise GitException, '"%s" already exists' % to_ref
+
+    sha1 = GRun('show-ref', '-s', from_ref).output_one_line()
+    try:
+        GRun('update-ref', to_ref, sha1, '0'*40).run()
+    except GitRunException:
+        raise GitException, 'Failed to create new ref %s' % to_ref
+    try:
+        GRun('update-ref', '-d', from_ref, sha1).run()
+    except GitRunException:
+        raise GitException, 'Failed to delete ref %s' % from_ref
+
+def rename_branch(from_name, to_name):
+    """Rename a git branch."""
+    rename_ref('refs/heads/%s' % from_name, 'refs/heads/%s' % to_name)
+    try:
+        if get_head_file() == from_name:
+            set_head_file(to_name)
+    except DetachedHeadException:
+        pass # detached HEAD, so the renamee can't be the current branch
+    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)
+
+# 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
     """
     """Update the cache information for the given files
     """

-    cache_files = __tree_status(files)
+    cache_files = tree_status(files, verbose = False)

 
     # everything is up-to-date
     if len(cache_files) == 0:
 
     # everything is up-to-date
     if len(cache_files) == 0:


@@ -280,21 +542,21 @@ def update_cache(files = [], force = False):
     rm_files =  [x[1] for x in cache_files if x[0] in ['D']]
     m_files =   [x[1] for x in cache_files if x[0] in ['M']]
 
     rm_files =  [x[1] for x in cache_files if x[0] in ['D']]
     m_files =   [x[1] for x in cache_files if x[0] in ['M']]
 

-    if add_files and __run('git-update-cache --add --', add_files) != 0:
-        raise GitException, 'Failed git-update-cache --add'
-    if rm_files and __run('git-update-cache --force-remove --', rm_files) != 0:
-        raise GitException, 'Failed git-update-cache --rm'
-    if m_files and __run('git-update-cache --', m_files) != 0:
-        raise GitException, 'Failed git-update-cache'
+    GRun('update-index', '--add', '--').xargs(add_files)
+    GRun('update-index', '--force-remove', '--').xargs(rm_files)
+    GRun('update-index', '--').xargs(m_files)

 
     return True
 
 
     return True
 

-def commit(message, files = [], parents = [], allowempty = False,
-           cache_update = True,
+def commit(message, files = None, parents = None, allowempty = False,
+           cache_update = True, tree_id = None, set_head = False,

            author_name = None, author_email = None, author_date = None,
            committer_name = None, committer_email = None):
     """Commit the current tree to repository
     """
            author_name = None, author_email = None, author_date = None,
            committer_name = None, committer_email = None):
     """Commit the current tree to repository
     """

+    if not parents:
+        parents = []
+

     # Get the tree status
     if cache_update and parents != []:
         changes = update_cache(files)
     # Get the tree status
     if cache_update and parents != []:
         changes = update_cache(files)


@@ -302,188 +564,403 @@ def commit(message, files = [], parents = [], allowempty = False,
             raise GitException, 'No changes to commit'
 
     # get the commit message
             raise GitException, 'No changes to commit'
 
     # get the commit message

-    f = file('.commitmsg', 'w+')
-    if message[-1:] == '\n':
-        f.write(message)
-    else:
-        print >> f, message
-    f.close()
+    if not message:
+        message = '\n'
+    elif message[-1:] != '\n':
+        message += '\n'

 
     # write the index to repository
 
     # write the index to repository

-    tree_id = _output_one_line('git-write-tree')
+    if tree_id == None:
+        tree_id = GRun('write-tree').output_one_line()
+        set_head = True

 
     # the commit
 
     # the commit

-    cmd = ''
+    env = {}

     if author_name:
     if author_name:

-        cmd += 'GIT_AUTHOR_NAME="%s" ' % author_name
+        env['GIT_AUTHOR_NAME'] = author_name

     if author_email:
     if author_email:

-        cmd += 'GIT_AUTHOR_EMAIL="%s" ' % author_email
+        env['GIT_AUTHOR_EMAIL'] = author_email

     if author_date:
     if author_date:

-        cmd += 'GIT_AUTHOR_DATE="%s" ' % author_date
+        env['GIT_AUTHOR_DATE'] = author_date

     if committer_name:
     if committer_name:

-        cmd += 'GIT_COMMITTER_NAME="%s" ' % committer_name
+        env['GIT_COMMITTER_NAME'] = committer_name

     if committer_email:
     if committer_email:

-        cmd += 'GIT_COMMITTER_EMAIL="%s" ' % committer_email
-    cmd += 'git-commit-tree %s' % tree_id
+        env['GIT_COMMITTER_EMAIL'] = committer_email
+    commit_id = GRun('commit-tree', tree_id,
+                     *sum([['-p', p] for p in parents], [])
+                     ).env(env).raw_input(message).output_one_line()
+    if set_head:
+        __set_head(commit_id)
+
+    return commit_id

 
 

-    # get the parents
-    for p in parents:
-        cmd += ' -p %s' % p
+def apply_diff(rev1, rev2, check_index = True, files = None):
+    """Apply the diff between rev1 and rev2 onto the current
+    index. This function doesn't need to raise an exception since it
+    is only used for fast-pushing a patch. If this operation fails,
+    the pushing would fall back to the three-way merge.
+    """
+    if check_index:
+        index_opt = ['--index']
+    else:
+        index_opt = []

 
 

-    cmd += ' < .commitmsg'
+    if not files:
+        files = []

 
 

-    commit_id = _output_one_line(cmd)
-    __set_head(commit_id)
-    os.remove('.commitmsg')
+    diff_str = diff(files, rev1, rev2)
+    if diff_str:
+        try:
+            GRun('apply', *index_opt).raw_input(
+                diff_str).discard_stderr().no_output()
+        except GitRunException:
+            return False

 
 

-    return commit_id
+    return True
+
+stages_re = re.compile('^([0-7]+) ([0-9a-f]{40}) ([1-3])\t(.*)$', re.S)

 
 

-def merge(base, head1, head2):
+def merge_recursive(base, head1, head2):

     """Perform a 3-way merge between base, head1 and head2 into the
     local tree
     """
     """Perform a 3-way merge between base, head1 and head2 into the
     local tree
     """

-    if __run('git-read-tree -u -m', [base, head1, head2]) != 0:
-        raise GitException, 'git-read-tree failed (local changes maybe?)'
-
-    # this can fail if there are conflicts
-    if os.system('git-merge-cache -o -q gitmergeonefile.py -a') != 0:
-        raise GitException, 'git-merge-cache failed (possible conflicts)'
-
-def status(files = [], modified = False, new = False, deleted = False,
-           conflict = False, unknown = False, noexclude = False):
-    """Show the tree status
-    """
-    cache_files = __tree_status(files, unknown = True, noexclude = noexclude)
-    all = not (modified or new or deleted or conflict or unknown)
-
-    if not all:
-        filestat = []
-        if modified:
-            filestat.append('M')
-        if new:
-            filestat.append('A')
-            filestat.append('N')
-        if deleted:
-            filestat.append('D')
-        if conflict:
-            filestat.append('C')
-        if unknown:
-            filestat.append('?')
-        cache_files = [x for x in cache_files if x[0] in filestat]
-
-    for fs in cache_files:
-        if all:
-            print '%s %s' % (fs[0], fs[1])
-        else:
-            print '%s' % fs[1]
-
-def diff(files = [], rev1 = 'HEAD', rev2 = None, out_fd = None):
+    refresh_index()
+    p = GRun('merge-recursive', base, '--', head1, head2).env(
+        { 'GITHEAD_%s' % base: 'ancestor',
+          'GITHEAD_%s' % head1: 'current',
+          'GITHEAD_%s' % head2: 'patched'}).returns([0, 1])
+    output = p.output_lines()
+    if p.exitcode:
+        # There were conflicts
+        conflicts = [l.strip() for l in output if l.startswith('CONFLICT')]
+        out.info(*conflicts)
+
+        # try the interactive merge or stage checkout (if enabled)
+        for filename in get_conflicts():
+            if (gitmergeonefile.merge(filename)):
+                # interactive merge succeeded
+                resolved([filename])
+
+        # any conflicts left unsolved?
+        cn = len(get_conflicts())
+        if cn:
+            raise GitException, "%d conflict(s)" % cn
+
+def diff(files = None, rev1 = 'HEAD', rev2 = None, diff_flags = [],
+         binary = True):

     """Show the diff between rev1 and rev2
     """
     """Show the diff between rev1 and rev2
     """

-    os.system('git-update-cache --refresh > /dev/null')
-
-    if rev2:
-        diff_str = _output(['git-diff-tree', '-p', rev1, rev2] + files)
+    if not files:
+        files = []
+    if binary and '--binary' not in diff_flags:
+        diff_flags = diff_flags + ['--binary']
+
+    if rev1 and rev2:
+        return GRun('diff-tree', '-p',
+                    *(diff_flags + [rev1, rev2, '--'] + files)).raw_output()
+    elif rev1 or rev2:
+        refresh_index()
+        if rev2:
+            return GRun('diff-index', '-p', '-R',
+                        *(diff_flags + [rev2, '--'] + files)).raw_output()
+        else:
+            return GRun('diff-index', '-p',
+                        *(diff_flags + [rev1, '--'] + files)).raw_output()

     else:
     else:

-        diff_str = _output(['git-diff-cache', '-p', rev1] + files)
+        return ''

 
 

-    if out_fd:
-        out_fd.write(diff_str)
-    else:
-        return diff_str
+def diffstat(diff):
+    """Return the diffstat of the supplied diff."""
+    return GRun('apply', '--stat', '--summary').raw_input(diff).raw_output()

 
 

-def diffstat(files = [], rev1 = 'HEAD', rev2 = None):
-    """Return the diffstat between rev1 and rev2
+def files(rev1, rev2, diff_flags = []):
+    """Return the files modified between rev1 and rev2

     """
 
     """
 

-    os.system('git-update-cache --refresh > /dev/null')
-    p=popen2.Popen3('git-apply --stat')
-    diff(files, rev1, rev2, p.tochild)
-    p.tochild.close()
-    str = p.fromchild.read().rstrip()
-    if p.wait():
-        raise GitException, 'git.diffstat failed'
-    return str
+    result = []
+    for line in GRun('diff-tree', *(diff_flags + ['-r', rev1, rev2])
+                     ).output_lines():
+        result.append('%s %s' % tuple(line.split(' ', 4)[-1].split('\t', 1)))

 
 

-def files(rev1, rev2):
-    """Return the files modified between rev1 and rev2
+    return '\n'.join(result)
+
+def barefiles(rev1, rev2):
+    """Return the files modified between rev1 and rev2, without status info

     """
     """

-    os.system('git-update-cache --refresh > /dev/null')

 
 

-    str = ''
-    for line in _output_lines('git-diff-tree -r %s %s' % (rev1, rev2)):
-        str += '%s %s\n' % tuple(line.rstrip().split(' ',4)[-1].split('\t',1))
+    result = []
+    for line in GRun('diff-tree', '-r', rev1, rev2).output_lines():
+        result.append(line.split(' ', 4)[-1].split('\t', 1)[-1])

 
 

-    return str.rstrip()
+    return '\n'.join(result)

 
 

-def checkout(files = [], tree_id = None, force = False):
+def pretty_commit(commit_id = 'HEAD', flags = []):
+    """Return a given commit (log + diff)
+    """
+    return GRun('show', *(flags + [commit_id])).raw_output()
+
+def checkout(files = None, tree_id = None, force = False):

     """Check out the given or all files
     """
     """Check out the given or all files
     """

-    if tree_id and __run('git-read-tree -m', [tree_id]) != 0:
-        raise GitException, 'Failed git-read-tree -m %s' % tree_id
+    if tree_id:
+        try:
+            GRun('read-tree', '--reset', tree_id).run()
+        except GitRunException:
+            raise GitException, 'Failed "git read-tree" --reset %s' % tree_id

 
 

-    checkout_cmd = 'git-checkout-cache -q -u'
+    cmd = ['checkout-index', '-q', '-u']

     if force:
     if force:

-        checkout_cmd += ' -f'
-    if len(files) == 0:
-        checkout_cmd += ' -a'
+        cmd.append('-f')
+    if files:
+        GRun(*(cmd + ['--'])).xargs(files)

     else:
     else:

-        checkout_cmd += ' --'
-
-    if __run(checkout_cmd, files) != 0:
-        raise GitException, 'Failed git-checkout-cache'
+        GRun(*(cmd + ['-a'])).run()

 
 

-def switch(tree_id):
+def switch(tree_id, keep = False):

     """Switch the tree to the given id
     """
     """Switch the tree to the given id
     """

-    if __run('git-read-tree -u -m', [get_head(), tree_id]) != 0:
-        raise GitException, 'git-read-tree failed (local changes maybe?)'
+    if keep:
+        # only update the index while keeping the local changes
+        GRun('read-tree', tree_id).run()
+    else:
+        refresh_index()
+        try:
+            GRun('read-tree', '-u', '-m', get_head(), tree_id).run()
+        except GitRunException:
+            raise GitException, 'read-tree failed (local changes maybe?)'

 
     __set_head(tree_id)
 
 
     __set_head(tree_id)
 

-def reset(tree_id = None):
+def reset(files = None, tree_id = None, check_out = True):

     """Revert the tree changes relative to the given tree_id. It removes
     any local changes
     """
     if not tree_id:
         tree_id = get_head()
 
     """Revert the tree changes relative to the given tree_id. It removes
     any local changes
     """
     if not tree_id:
         tree_id = get_head()
 

-    cache_files = __tree_status(tree_id = tree_id)
-    rm_files =  [x[1] for x in cache_files if x[0] in ['D']]
+    if check_out:
+        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']]
+
+        checkout(files, tree_id, True)
+        # checkout doesn't remove files
+        map(os.remove, rm_files)
+
+    # if the reset refers to the whole tree, switch the HEAD as well
+    if not files:
+        __set_head(tree_id)
+
+def resolved(filenames, reset = None):
+    if reset:
+        stage = {'ancestor': 1, 'current': 2, 'patched': 3}[reset]
+        GRun('checkout-index', '--no-create', '--stage=%d' % stage,
+             '--stdin', '-z').input_nulterm(filenames).no_output()
+    GRun('update-index', '--add', '--').xargs(filenames)
+    for filename in filenames:
+        gitmergeonefile.clean_up(filename)
+        # update the access and modificatied times
+        os.utime(filename, None)
+
+def fetch(repository = 'origin', refspec = None):
+    """Fetches changes from the remote repository, using 'git fetch'
+    by default.
+    """
+    # we update the HEAD
+    __clear_head_cache()

 
 

-    checkout(tree_id = tree_id, force = True)
-    __set_head(tree_id)
+    args = [repository]
+    if refspec:
+        args.append(refspec)

 
 

-    # checkout doesn't remove files
-    map(os.remove, rm_files)
+    command = config.get('branch.%s.stgit.fetchcmd' % get_head_file()) or \
+              config.get('stgit.fetchcmd')
+    Run(*(command.split() + args)).run()

 
 def pull(repository = 'origin', refspec = None):
 
 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.

     """
     """

+    # we update the HEAD
+    __clear_head_cache()
+

     args = [repository]
     if refspec:
         args.append(refspec)
 
     args = [repository]
     if refspec:
         args.append(refspec)
 

-    if __run('git pull', args) != 0:
-        raise GitException, 'Failed "git pull %s"' % repository
+    command = config.get('branch.%s.stgit.pullcmd' % get_head_file()) or \
+              config.get('stgit.pullcmd')
+    Run(*(command.split() + args)).run()
+
+def rebase(tree_id = None):
+    """Rebase the current tree to the give tree_id. The tree_id
+    argument may be something other than a GIT id if an external
+    command is invoked.
+    """
+    command = config.get('branch.%s.stgit.rebasecmd' % get_head_file()) \
+                or config.get('stgit.rebasecmd')
+    if tree_id:
+        args = [tree_id]
+    elif command:
+        args = []
+    else:
+        raise GitException, 'Default rebasing requires a commit id'
+    if command:
+        # clear the HEAD cache as the custom rebase command will update it
+        __clear_head_cache()
+        Run(*(command.split() + args)).run()
+    else:
+        # default rebasing
+        reset(tree_id = tree_id)

 
 

-def apply_patch(filename = None):
-    """Apply a patch onto the current index. There must not be any
-    local changes in the tree, otherwise the command fails
+def repack():
+    """Repack all objects into a single pack

     """
     """

-    os.system('git-update-cache --refresh > /dev/null')
+    GRun('repack', '-a', '-d', '-f').run()

 
 

-    if filename:
-        if __run('git-apply --index', [filename]) != 0:
-            raise GitException, 'Patch does not apply cleanly'
+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
+    """
+    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:
     else:

-        _input('git-apply --index', sys.stdin)
+        refresh_index()
+
+    try:
+        GRun('apply', '--index').raw_input(diff).no_output()
+    except GitRunException:
+        if base:
+            switch(orig_head)
+        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)
+        merge_recursive(base, orig_head, top)

 
 def clone(repository, local_dir):
     """Clone a remote repository. At the moment, just use the
     'git clone' script
     """
 
 def clone(repository, local_dir):
     """Clone a remote repository. At the moment, just use the
     'git clone' script
     """

-    if __run('git clone', [repository, local_dir]) != 0:
-        raise GitException, 'Failed "git clone %s %s"' \
-              % (repository, local_dir)
+    GRun('clone', repository, local_dir).run()
+
+def modifying_revs(files, base_rev, head_rev):
+    """Return the revisions from the list modifying the given files."""
+    return GRun('rev-list', '%s..%s' % (base_rev, head_rev), '--', *files
+                ).output_lines()
+
+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 []
+
+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()
+
+    if not fetch_head:
+        out.warn('No for-merge remote head found in FETCH_HEAD')
+
+    # 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 GRun('show-ref').output_lines()]