X-Git-Url: https://git.distorted.org.uk/~mdw/stgit/blobdiff_plain/7438e0983a0fb852697d7162f6a1812d7ebb0c25..ea09f8ce7b1bcea38a7d9f0079a28c6109989342:/stgit/git.py

diff --git a/stgit/git.py b/stgit/git.py
index 1f57481..4d01fc2 100644
--- a/stgit/git.py
+++ b/stgit/git.py
@@ -18,19 +18,30 @@ 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, popen2, re, gitmergeonefile
+import sys, os, re, gitmergeonefile
 from shutil import copyfile
 
+from stgit.exception import *
 from stgit import basedir
 from stgit.utils import *
+from stgit.out import *
+from stgit.run import *
 from stgit.config import config
-from sets import Set
 
 # git exception class
-class GitException(Exception):
+class GitException(StgException):
     pass
 
-
+# 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
@@ -74,19 +85,21 @@ class Commit:
     def __init__(self, id_hash):
         self.__id_hash = id_hash
 
-        lines = _output_lines(['git-cat-file', 'commit', id_hash])
+        lines = GRun('cat-file', 'commit', id_hash).output_lines()
         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]
-            if field[0] == 'author':
-                self.__author = field[1]
-            if field[0] == 'committer':
-                self.__committer = field[1]
-        self.__log = ''.join(lines[i+1:])
+            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
@@ -102,8 +115,8 @@ class Commit:
             return None
 
     def get_parents(self):
-        return _output_lines(['git-rev-list', '--parents', '--max-count=1',
-                              self.__id_hash])[0].split()[1:]
+        return GRun('rev-list', '--parents', '--max-count=1', self.__id_hash
+                    ).output_one_line().split()[1:]
 
     def get_author(self):
         return self.__author
@@ -140,125 +153,130 @@ def get_commit(id_hash):
 def get_conflicts():
     """Return the list of file conflicts
     """
-    conflicts_file = os.path.join(basedir.get(), '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
+    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 _input(cmd, file_desc):
-    p = popen2.Popen3(cmd, True)
-    while True:
-        line = file_desc.readline()
-        if not line:
-            break
-        p.tochild.write(line)
-    p.tochild.close()
-    if p.wait():
-        raise GitException, '%s failed (%s)' % (' '.join(cmd),
-                                                p.childerr.read().strip())
-
-def _input_str(cmd, string):
-    p = popen2.Popen3(cmd, True)
-    p.tochild.write(string)
-    p.tochild.close()
-    if p.wait():
-        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)' % (' '.join(cmd),
-                                                p.childerr.read().strip())
-    return output
-
-def _output_one_line(cmd, file_desc = None):
-    p=popen2.Popen3(cmd, True)
-    if file_desc != None:
-        for line in file_desc:
-            p.tochild.write(line)
-        p.tochild.close()
-    output = p.fromchild.readline().strip()
-    if p.wait():
-        raise GitException, '%s failed (%s)' % (' '.join(cmd),
-                                                p.childerr.read().strip())
-    return output
-
-def _output_lines(cmd):
-    p=popen2.Popen3(cmd, True)
-    lines = p.fromchild.readlines()
-    if p.wait():
-        raise GitException, '%s failed (%s)' % (' '.join(cmd),
-                                                p.childerr.read().strip())
-    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.  
+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.
     """
-    
-    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
+    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 tree_status(files = None, tree_id = 'HEAD', unknown = False,
-                  noexclude = True, verbose = False, diff_flags = []):
-    """Returns a list of pairs - [status, filename]
+                  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).
+
+    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.
     """
+    assert not files or not unknown
+
     if verbose:
         out.start('Checking for changes in the working directory')
 
     refresh_index()
 
-    if not files:
+    if files is None:
         files = []
     cache_files = []
 
     # unknown files
     if unknown:
-        exclude_file = os.path.join(basedir.get(), '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', '--directory']
-                        + 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()
-    if not conflicts:
-        conflicts = []
-    cache_files += [('C', filename) for filename in conflicts]
-
-    # the rest
-    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)
+    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()
@@ -270,6 +288,14 @@ def local_changes(verbose = True):
     """
     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
 
@@ -282,11 +308,19 @@ def get_head():
         __head = rev_parse('HEAD')
     return __head
 
+class DetachedHeadException(GitException):
+    def __init__(self):
+        GitException.__init__(self, 'Not on any branch')
+
 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']))
+    """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
@@ -294,14 +328,20 @@ def set_head_file(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',
-             [os.path.join('refs', 'heads', ref)]) != 0:
+    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):
-    """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)
+    set_ref('refs/heads/%s' % branch, val)
 
 def __set_head(val):
     """Sets the HEAD value
@@ -309,7 +349,7 @@ def __set_head(val):
     global __head
 
     if not __head or __head != val:
-        set_branch('HEAD', val)
+        set_ref('HEAD', val)
         __head = val
 
     # only allow SHA1 hashes
@@ -325,26 +365,26 @@ def __clear_head_cache():
 def refresh_index():
     """Refresh index with stat() information from the working directory.
     """
-    __run('git-update-index -q --unmerged --refresh')
+    GRun('update-index', '-q', '--unmerged', '--refresh').run()
 
 def rev_parse(git_id):
     """Parse the string and return a verified SHA1 id
     """
     try:
-        return _output_one_line(['git-rev-parse', '--verify', git_id])
-    except GitException:
+        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 branch_exists(branch):
-    """Existence check for the named branch
-    """
-    branch = os.path.join('refs', 'heads', branch)
-    for line in _output_lines('git-rev-parse --symbolic --all 2>&1'):
-        if line.strip() == branch:
-            return True
-        if re.compile('[ |/]'+branch+' ').search(line):
-            raise GitException, 'Bogus branch: %s' % line
-    return False
+    return ref_exists('refs/heads/%s' % branch)
 
 def create_branch(new_branch, tree_id = None):
     """Create a new branch in the git repository
@@ -352,13 +392,20 @@ def create_branch(new_branch, tree_id = None):
     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:
-        switch(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'))
@@ -371,145 +418,60 @@ def switch_branch(new_branch):
     if not branch_exists(new_branch):
         raise GitException, 'Branch "%s" does not exist' % new_branch
 
-    tree_id = rev_parse(os.path.join('refs', 'heads', new_branch)
-                        + '^{commit}')
+    tree_id = rev_parse('refs/heads/%s^{commit}' % new_branch)
     if tree_id != get_head():
         refresh_index()
-        if __run('git-read-tree -u -m', [get_head(), tree_id]) != 0:
-            raise GitException, 'git-read-tree failed (local changes maybe?)'
+        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 a git branch
-    """
-    if not branch_exists(name):
-        raise GitException, 'Branch "%s" does not exist' % name
-    remove_file_and_dirs(os.path.join(basedir.get(), 'refs', 'heads'),
-                         name)
+    delete_ref('refs/heads/%s' % name)
 
-def rename_branch(from_name, to_name):
-    """Rename a git branch
-    """
-    if not branch_exists(from_name):
-        raise GitException, 'Branch "%s" does not exist' % from_name
-    if branch_exists(to_name):
-        raise GitException, 'Branch "%s" already exists' % to_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
 
-    if get_head_file() == from_name:
-        set_head_file(to_name)
-    rename(os.path.join(basedir.get(), 'refs', 'heads'),
-           from_name, to_name)
+    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)
 
-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
-
-    if files:
-        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
-    """
-    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-index --remove --', files)
-    else:
-        if files:
-            __run('git-update-index --force-remove --', files)
-
 # Persons caching
 __user = None
 __author = None
@@ -564,9 +526,6 @@ def 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, verbose = False)
 
     # everything is up-to-date
@@ -583,23 +542,18 @@ def update_cache(files = None, 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']]
 
-    if add_files and __run('git-update-index --add --', add_files) != 0:
-        raise GitException, 'Failed git-update-index --add'
-    if rm_files and __run('git-update-index --force-remove --', rm_files) != 0:
-        raise GitException, 'Failed git-update-index --rm'
-    if m_files and __run('git-update-index --', m_files) != 0:
-        raise GitException, 'Failed git-update-index'
+    GRun('update-index', '--add', '--').xargs(add_files)
+    GRun('update-index', '--force-remove', '--').xargs(rm_files)
+    GRun('update-index', '--').xargs(m_files)
 
     return True
 
 def commit(message, files = None, parents = None, allowempty = False,
-           cache_update = True, tree_id = None,
+           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
     """
-    if not files:
-        files = []
     if not parents:
         parents = []
 
@@ -615,33 +569,27 @@ def commit(message, files = None, parents = None, allowempty = False,
     elif message[-1:] != '\n':
         message += '\n'
 
-    must_switch = True
     # write the index to repository
     if tree_id == None:
-        tree_id = _output_one_line(['git-write-tree'])
-    else:
-        must_switch = False
+        tree_id = GRun('write-tree').output_one_line()
+        set_head = True
 
     # the commit
-    cmd = ['env']
+    env = {}
     if author_name:
-        cmd += ['GIT_AUTHOR_NAME=%s' % author_name]
+        env['GIT_AUTHOR_NAME'] = author_name
     if author_email:
-        cmd += ['GIT_AUTHOR_EMAIL=%s' % author_email]
+        env['GIT_AUTHOR_EMAIL'] = author_email
     if author_date:
-        cmd += ['GIT_AUTHOR_DATE=%s' % author_date]
+        env['GIT_AUTHOR_DATE'] = author_date
     if committer_name:
-        cmd += ['GIT_COMMITTER_NAME=%s' % committer_name]
+        env['GIT_COMMITTER_NAME'] = committer_name
     if committer_email:
-        cmd += ['GIT_COMMITTER_EMAIL=%s' % committer_email]
-    cmd += ['git-commit-tree', tree_id]
-
-    # get the parents
-    for p in parents:
-        cmd += ['-p', p]
-
-    commit_id = _output_one_line(cmd, message)
-    if must_switch:
+        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
@@ -663,208 +611,119 @@ def apply_diff(rev1, rev2, check_index = True, files = None):
     diff_str = diff(files, rev1, rev2)
     if diff_str:
         try:
-            _input_str(['git-apply'] + index_opt, diff_str)
-        except GitException:
+            GRun('apply', *index_opt).raw_input(
+                diff_str).discard_stderr().no_output()
+        except GitRunException:
             return False
 
     return True
 
-def merge(base, head1, head2, recursive = False):
+stages_re = re.compile('^([0-7]+) ([0-9a-f]{40}) ([1-3])\t(.*)$', re.S)
+
+def merge_recursive(base, head1, head2):
     """Perform a 3-way merge between base, head1 and head2 into the
     local tree
     """
     refresh_index()
-
-    err_output = None
-    if recursive:
-        # this operation tracks renames but it is slower (used in
-        # general when pushing or picking patches)
-        try:
-            # use _output() to mask the verbose prints of the tool
-            _output(['git-merge-recursive', base, '--', head1, head2])
-        except GitException, ex:
-            err_output = str(ex)
-            pass
-    else:
-        # the fast case where we don't track renames (used when the
-        # distance between base and heads is small, i.e. folding or
-        # synchronising patches)
-        if __run('git-read-tree -u -m --aggressive',
-                 [base, head1, head2]) != 0:
-            raise GitException, 'git-read-tree failed (local changes maybe?)'
-
-    # check the index for unmerged entries
-    files = {}
-    stages_re = re.compile('^([0-7]+) ([0-9a-f]{40}) ([1-3])\t(.*)$', re.S)
-
-    for line in _output(['git-ls-files', '--unmerged', '--stage', '-z']).split('\0'):
-        if not line:
-            continue
-
-        mode, hash, stage, path = stages_re.findall(line)[0]
-
-        if not path in files:
-            files[path] = {}
-            files[path]['1'] = ('', '')
-            files[path]['2'] = ('', '')
-            files[path]['3'] = ('', '')
-
-        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],
-                                 stages['2'][0], stages['3'][0]) != 0:
-            errors = True
-
-    if errors:
-        raise GitException, 'GIT index merging failed (possible conflicts)'
-
-def status(files = None, modified = False, new = False, deleted = 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,
-                                diff_flags = diff_flags)
-    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 files and not fs[1] in files:
-            continue
-        if all:
-            out.stdout('%s %s' % (fs[0], fs[1]))
-        else:
-            out.stdout('%s' % fs[1])
-
-def diff(files = None, rev1 = 'HEAD', rev2 = None, out_fd = None,
-         diff_flags = []):
+    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
     """
     if not files:
         files = []
+    if binary and '--binary' not in diff_flags:
+        diff_flags = diff_flags + ['--binary']
 
     if rev1 and rev2:
-        diff_str = _output(['git-diff-tree', '-p'] + diff_flags
-                           + [rev1, rev2, '--'] + files)
+        return GRun('diff-tree', '-p',
+                    *(diff_flags + [rev1, rev2, '--'] + files)).raw_output()
     elif rev1 or rev2:
         refresh_index()
         if rev2:
-            diff_str = _output(['git-diff-index', '-p', '-R']
-                               + diff_flags + [rev2, '--'] + files)
+            return GRun('diff-index', '-p', '-R',
+                        *(diff_flags + [rev2, '--'] + files)).raw_output()
         else:
-            diff_str = _output(['git-diff-index', '-p']
-                               + diff_flags + [rev1, '--'] + files)
-    else:
-        diff_str = ''
-
-    if out_fd:
-        out_fd.write(diff_str)
+            return GRun('diff-index', '-p',
+                        *(diff_flags + [rev1, '--'] + files)).raw_output()
     else:
-        return diff_str
-
-def diffstat(files = None, rev1 = 'HEAD', rev2 = None):
-    """Return the diffstat between rev1 and rev2
-    """
-    if not files:
-        files = []
-
-    p=popen2.Popen3('git-apply --stat')
-    diff(files, rev1, rev2, p.tochild)
-    p.tochild.close()
-    diff_str = p.fromchild.read().rstrip()
-    if p.wait():
-        raise GitException, 'git.diffstat failed'
-    return diff_str
+        return ''
 
 def files(rev1, rev2, diff_flags = []):
     """Return the files modified between rev1 and rev2
     """
 
-    result = ''
-    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))
+    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)))
 
-    return result.rstrip()
+    return '\n'.join(result)
 
 def barefiles(rev1, rev2):
     """Return the files modified between rev1 and rev2, without status info
     """
 
-    result = ''
-    for line in _output_lines(['git-diff-tree', '-r', rev1, rev2]):
-        result += '%s\n' % line.rstrip().split(' ',4)[-1].split('\t',1)[-1]
+    result = []
+    for line in GRun('diff-tree', '-r', rev1, rev2).output_lines():
+        result.append(line.split(' ', 4)[-1].split('\t', 1)[-1])
 
-    return result.rstrip()
+    return '\n'.join(result)
 
-def pretty_commit(commit_id = 'HEAD', diff_flags = []):
+def pretty_commit(commit_id = 'HEAD', flags = []):
     """Return a given commit (log + diff)
     """
-    return _output(['git-diff-tree'] + diff_flags +
-                   ['--cc', '--always', '--pretty', '-r', commit_id])
+    return GRun('show', *(flags + [commit_id])).raw_output()
 
 def checkout(files = None, tree_id = None, force = False):
     """Check out the given or all files
     """
-    if not files:
-        files = []
-
-    if tree_id and __run('git-read-tree --reset', [tree_id]) != 0:
-        raise GitException, 'Failed git-read-tree --reset %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-index -q -u'
+    cmd = ['checkout-index', '-q', '-u']
     if force:
-        checkout_cmd += ' -f'
-    if len(files) == 0:
-        checkout_cmd += ' -a'
+        cmd.append('-f')
+    if files:
+        GRun(*(cmd + ['--'])).xargs(files)
     else:
-        checkout_cmd += ' --'
-
-    if __run(checkout_cmd, files) != 0:
-        raise GitException, 'Failed git-checkout-index'
+        GRun(*(cmd + ['-a'])).run()
 
 def switch(tree_id, keep = False):
     """Switch the tree to the given id
     """
-    if not keep:
+    if keep:
+        # only update the index while keeping the local changes
+        GRun('read-tree', tree_id).run()
+    else:
         refresh_index()
-        if __run('git-read-tree -u -m', [get_head(), tree_id]) != 0:
-            raise GitException, 'git-read-tree failed (local changes maybe?)'
+        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)
 
@@ -888,8 +747,19 @@ def reset(files = None, tree_id = None, check_out = True):
     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'
+    """Fetches changes from the remote repository, using 'git fetch'
     by default.
     """
     # we update the HEAD
@@ -901,11 +771,10 @@ def fetch(repository = 'origin', refspec = None):
 
     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)
+    Run(*(command.split() + args)).run()
 
 def pull(repository = 'origin', refspec = None):
-    """Fetches changes from the remote repository, using 'git-pull'
+    """Fetches changes from the remote repository, using 'git pull'
     by default.
     """
     # we update the HEAD
@@ -917,13 +786,33 @@ def pull(repository = 'origin', refspec = None):
 
     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)
+    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 repack():
     """Repack all objects into a single pack
     """
-    __run('git-repack -a -d -f')
+    GRun('repack', '-a', '-d', '-f').run()
 
 def apply_patch(filename = None, diff = None, base = None,
                 fail_dump = True):
@@ -946,8 +835,8 @@ def apply_patch(filename = None, diff = None, base = None,
         refresh_index()
 
     try:
-        _input_str(['git-apply', '--index'], diff)
-    except GitException:
+        GRun('apply', '--index').raw_input(diff).no_output()
+    except GitRunException:
         if base:
             switch(orig_head)
         if fail_dump:
@@ -963,24 +852,18 @@ def apply_patch(filename = None, diff = None, base = None,
         top = commit(message = 'temporary commit used for applying a patch',
                      parents = [base])
         switch(orig_head)
-        merge(base, orig_head, top)
+        merge_recursive(base, orig_head, top)
 
 def clone(repository, local_dir):
     """Clone a remote repository. At the moment, just use the
-    'git-clone' script
+    '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
-    """
-    cmd = ['git-rev-list', '%s..%s' % (base_rev, head_rev), '--']
-    revs = [line.strip() for line in _output_lines(cmd + files)]
-
-    return revs
-
+    """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)
@@ -995,7 +878,6 @@ def refspec_remotepart(refspec):
         return m.group(1)
     else:
         raise GitException, 'Cannot parse refspec "%s"' % line
-    
 
 def __remotes_from_config():
     return config.sections_matching(r'remote\.(.*)\.url')
@@ -1005,15 +887,14 @@ def __remotes_from_dir(dir):
     if os.path.exists(d):
         return os.listdir(d)
     else:
-        return None
+        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'))
+    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
@@ -1063,11 +944,14 @@ def fetch_head():
         m = re.match('^([^\t]*)\t\t', line)
         if m:
             if fetch_head:
-                raise GitException, "StGit does not support multiple 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
 
@@ -1075,4 +959,4 @@ 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'])]
+    return [line.split()[1] for line in GRun('show-ref').output_lines()]