mdw@git.distorted.org.uk Git - stgit/blob - stgit/git.py

   1 """Python GIT interface
   2 """
   3
   4 __copyright__ = """
   5 Copyright (C) 2005, Catalin Marinas <catalin.marinas@gmail.com>
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License version 2 as
   9 published by the Free Software Foundation.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19 """
  20
  21 import sys, os, popen2, re, gitmergeonefile
  22
  23 from stgit import basedir
  24 from stgit.utils import *
  25 from stgit.config import config
  26
  27 # git exception class
  28 class GitException(Exception):
  29     pass
  30
  31
  32
  33 #
  34 # Classes
  35 #
  36 class Commit:
  37     """Handle the commit objects
  38     """
  39     def __init__(self, id_hash):
  40         self.__id_hash = id_hash
  41
  42         lines = _output_lines('git-cat-file commit %s' % id_hash)
  43         for i in range(len(lines)):
  44             line = lines[i]
  45             if line == '\n':
  46                 break
  47             field = line.strip().split(' ', 1)
  48             if field[0] == 'tree':
  49                 self.__tree = field[1]
  50             if field[0] == 'author':
  51                 self.__author = field[1]
  52             if field[0] == 'committer':
  53                 self.__committer = field[1]
  54         self.__log = ''.join(lines[i+1:])
  55
  56     def get_id_hash(self):
  57         return self.__id_hash
  58
  59     def get_tree(self):
  60         return self.__tree
  61
  62     def get_parent(self):
  63         parents = self.get_parents()
  64         if parents:
  65             return parents[0]
  66         else:
  67             return None
  68
  69     def get_parents(self):
  70         return _output_lines('git-rev-list --parents --max-count=1 %s'
  71                              % self.__id_hash)[0].split()[1:]
  72
  73     def get_author(self):
  74         return self.__author
  75
  76     def get_committer(self):
  77         return self.__committer
  78
  79     def get_log(self):
  80         return self.__log
  81
  82     def __str__(self):
  83         return self.get_id_hash()
  84
  85 # dictionary of Commit objects, used to avoid multiple calls to git
  86 __commits = dict()
  87
  88 #
  89 # Functions
  90 #
  91
  92 def get_commit(id_hash):
  93     """Commit objects factory. Save/look-up them in the __commits
  94     dictionary
  95     """
  96     global __commits
  97
  98     if id_hash in __commits:
  99         return __commits[id_hash]
 100     else:
 101         commit = Commit(id_hash)
 102         __commits[id_hash] = commit
 103         return commit
 104
 105 def get_conflicts():
 106     """Return the list of file conflicts
 107     """
 108     conflicts_file = os.path.join(basedir.get(), 'conflicts')
 109     if os.path.isfile(conflicts_file):
 110         f = file(conflicts_file)
 111         names = [line.strip() for line in f.readlines()]
 112         f.close()
 113         return names
 114     else:
 115         return None
 116
 117 def _input(cmd, file_desc):
 118     p = popen2.Popen3(cmd, True)
 119     while True:
 120         line = file_desc.readline()
 121         if not line:
 122             break
 123         p.tochild.write(line)
 124     p.tochild.close()
 125     if p.wait():
 126         raise GitException, '%s failed (%s)' % (str(cmd),
 127                                                 p.childerr.read().strip())
 128
 129 def _input_str(cmd, string):
 130     p = popen2.Popen3(cmd, True)
 131     p.tochild.write(string)
 132     p.tochild.close()
 133     if p.wait():
 134         raise GitException, '%s failed (%s)' % (str(cmd),
 135                                                 p.childerr.read().strip())
 136
 137 def _output(cmd):
 138     p=popen2.Popen3(cmd, True)
 139     output = p.fromchild.read()
 140     if p.wait():
 141         raise GitException, '%s failed (%s)' % (str(cmd),
 142                                                 p.childerr.read().strip())
 143     return output
 144
 145 def _output_one_line(cmd, file_desc = None):
 146     p=popen2.Popen3(cmd, True)
 147     if file_desc != None:
 148         for line in file_desc:
 149             p.tochild.write(line)
 150         p.tochild.close()
 151     output = p.fromchild.readline().strip()
 152     if p.wait():
 153         raise GitException, '%s failed (%s)' % (str(cmd),
 154                                                 p.childerr.read().strip())
 155     return output
 156
 157 def _output_lines(cmd):
 158     p=popen2.Popen3(cmd, True)
 159     lines = p.fromchild.readlines()
 160     if p.wait():
 161         raise GitException, '%s failed (%s)' % (str(cmd),
 162                                                 p.childerr.read().strip())
 163     return lines
 164
 165 def __run(cmd, args=None):
 166     """__run: runs cmd using spawnvp.
 167
 168     Runs cmd using spawnvp.  The shell is avoided so it won't mess up
 169     our arguments.  If args is very large, the command is run multiple
 170     times; args is split xargs style: cmd is passed on each
 171     invocation.  Unlike xargs, returns immediately if any non-zero
 172     return code is received.
 173     """
 174
 175     args_l=cmd.split()
 176     if args is None:
 177         args = []
 178     for i in range(0, len(args)+1, 100):
 179         r=os.spawnvp(os.P_WAIT, args_l[0], args_l + args[i:min(i+100, len(args))])
 180     if r:
 181         return r
 182     return 0
 183
 184 def __tree_status(files = None, tree_id = 'HEAD', unknown = False,
 185                   noexclude = True, verbose = False):
 186     """Returns a list of pairs - [status, filename]
 187     """
 188     if verbose:
 189         print 'Checking for changes in the working directory...',
 190         sys.stdout.flush()
 191
 192     refresh_index()
 193
 194     if not files:
 195         files = []
 196     cache_files = []
 197
 198     # unknown files
 199     if unknown:
 200         exclude_file = os.path.join(basedir.get(), 'info', 'exclude')
 201         base_exclude = ['--exclude=%s' % s for s in
 202                         ['*.[ao]', '*.pyc', '.*', '*~', '#*', 'TAGS', 'tags']]
 203         base_exclude.append('--exclude-per-directory=.gitignore')
 204
 205         if os.path.exists(exclude_file):
 206             extra_exclude = ['--exclude-from=%s' % exclude_file]
 207         else:
 208             extra_exclude = []
 209         if noexclude:
 210             extra_exclude = base_exclude = []
 211
 212         lines = _output_lines(['git-ls-files', '--others', '--directory']
 213                         + base_exclude + extra_exclude)
 214         cache_files += [('?', line.strip()) for line in lines]
 215
 216     # conflicted files
 217     conflicts = get_conflicts()
 218     if not conflicts:
 219         conflicts = []
 220     cache_files += [('C', filename) for filename in conflicts]
 221
 222     # the rest
 223     for line in _output_lines(['git-diff-index', tree_id, '--'] + files):
 224         fs = tuple(line.rstrip().split(' ',4)[-1].split('\t',1))
 225         if fs[1] not in conflicts:
 226             cache_files.append(fs)
 227
 228     if verbose:
 229         print 'done'
 230
 231     return cache_files
 232
 233 def local_changes():
 234     """Return true if there are local changes in the tree
 235     """
 236     return len(__tree_status(verbose = True)) != 0
 237
 238 # HEAD value cached
 239 __head = None
 240
 241 def get_head():
 242     """Verifies the HEAD and returns the SHA1 id that represents it
 243     """
 244     global __head
 245
 246     if not __head:
 247         __head = rev_parse('HEAD')
 248     return __head
 249
 250 def get_head_file():
 251     """Returns the name of the file pointed to by the HEAD link
 252     """
 253     return strip_prefix('refs/heads/',
 254                         _output_one_line('git-symbolic-ref HEAD'))
 255
 256 def set_head_file(ref):
 257     """Resets HEAD to point to a new ref
 258     """
 259     # head cache flushing is needed since we might have a different value
 260     # in the new head
 261     __clear_head_cache()
 262     if __run('git-symbolic-ref HEAD',
 263              [os.path.join('refs', 'heads', ref)]) != 0:
 264         raise GitException, 'Could not set head to "%s"' % ref
 265
 266 def __set_head(val):
 267     """Sets the HEAD value
 268     """
 269     global __head
 270
 271     if not __head or __head != val:
 272         if __run('git-update-ref HEAD', [val]) != 0:
 273             raise GitException, 'Could not update HEAD to "%s".' % val
 274         __head = val
 275
 276     # only allow SHA1 hashes
 277     assert(len(__head) == 40)
 278
 279 def __clear_head_cache():
 280     """Sets the __head to None so that a re-read is forced
 281     """
 282     global __head
 283
 284     __head = None
 285
 286 def refresh_index():
 287     """Refresh index with stat() information from the working directory.
 288     """
 289     __run('git-update-index -q --unmerged --refresh')
 290
 291 def rev_parse(git_id):
 292     """Parse the string and return a verified SHA1 id
 293     """
 294     try:
 295         return _output_one_line(['git-rev-parse', '--verify', git_id])
 296     except GitException:
 297         raise GitException, 'Unknown revision: %s' % git_id
 298
 299 def branch_exists(branch):
 300     """Existence check for the named branch
 301     """
 302     branch = os.path.join('refs', 'heads', branch)
 303     for line in _output_lines('git-rev-parse --symbolic --all 2>&1'):
 304         if line.strip() == branch:
 305             return True
 306         if re.compile('[ |/]'+branch+' ').search(line):
 307             raise GitException, 'Bogus branch: %s' % line
 308     return False
 309
 310 def create_branch(new_branch, tree_id = None):
 311     """Create a new branch in the git repository
 312     """
 313     if branch_exists(new_branch):
 314         raise GitException, 'Branch "%s" already exists' % new_branch
 315
 316     current_head = get_head()
 317     set_head_file(new_branch)
 318     __set_head(current_head)
 319
 320     # a checkout isn't needed if new branch points to the current head
 321     if tree_id:
 322         switch(tree_id)
 323
 324     if os.path.isfile(os.path.join(basedir.get(), 'MERGE_HEAD')):
 325         os.remove(os.path.join(basedir.get(), 'MERGE_HEAD'))
 326
 327 def switch_branch(new_branch):
 328     """Switch to a git branch
 329     """
 330     global __head
 331
 332     if not branch_exists(new_branch):
 333         raise GitException, 'Branch "%s" does not exist' % new_branch
 334
 335     tree_id = rev_parse(os.path.join('refs', 'heads', new_branch)
 336                         + '^{commit}')
 337     if tree_id != get_head():
 338         refresh_index()
 339         if __run('git-read-tree -u -m', [get_head(), tree_id]) != 0:
 340             raise GitException, 'git-read-tree failed (local changes maybe?)'
 341         __head = tree_id
 342     set_head_file(new_branch)
 343
 344     if os.path.isfile(os.path.join(basedir.get(), 'MERGE_HEAD')):
 345         os.remove(os.path.join(basedir.get(), 'MERGE_HEAD'))
 346
 347 def delete_branch(name):
 348     """Delete a git branch
 349     """
 350     if not branch_exists(name):
 351         raise GitException, 'Branch "%s" does not exist' % name
 352     remove_file_and_dirs(os.path.join(basedir.get(), 'refs', 'heads'),
 353                          name)
 354
 355 def rename_branch(from_name, to_name):
 356     """Rename a git branch
 357     """
 358     if not branch_exists(from_name):
 359         raise GitException, 'Branch "%s" does not exist' % from_name
 360     if branch_exists(to_name):
 361         raise GitException, 'Branch "%s" already exists' % to_name
 362
 363     if get_head_file() == from_name:
 364         set_head_file(to_name)
 365     rename(os.path.join(basedir.get(), 'refs', 'heads'),
 366            from_name, to_name)
 367
 368 def add(names):
 369     """Add the files or recursively add the directory contents
 370     """
 371     # generate the file list
 372     files = []
 373     for i in names:
 374         if not os.path.exists(i):
 375             raise GitException, 'Unknown file or directory: %s' % i
 376
 377         if os.path.isdir(i):
 378             # recursive search. We only add files
 379             for root, dirs, local_files in os.walk(i):
 380                 for name in [os.path.join(root, f) for f in local_files]:
 381                     if os.path.isfile(name):
 382                         files.append(os.path.normpath(name))
 383         elif os.path.isfile(i):
 384             files.append(os.path.normpath(i))
 385         else:
 386             raise GitException, '%s is not a file or directory' % i
 387
 388     if files:
 389         if __run('git-update-index --add --', files):
 390             raise GitException, 'Unable to add file'
 391
 392 def rm(files, force = False):
 393     """Remove a file from the repository
 394     """
 395     if not force:
 396         for f in files:
 397             if os.path.exists(f):
 398                 raise GitException, '%s exists. Remove it first' %f
 399         if files:
 400             __run('git-update-index --remove --', files)
 401     else:
 402         if files:
 403             __run('git-update-index --force-remove --', files)
 404
 405 def update_cache(files = None, force = False):
 406     """Update the cache information for the given files
 407     """
 408     if not files:
 409         files = []
 410
 411     cache_files = __tree_status(files, verbose = False)
 412
 413     # everything is up-to-date
 414     if len(cache_files) == 0:
 415         return False
 416
 417     # check for unresolved conflicts
 418     if not force and [x for x in cache_files
 419                       if x[0] not in ['M', 'N', 'A', 'D']]:
 420         raise GitException, 'Updating cache failed: unresolved conflicts'
 421
 422     # update the cache
 423     add_files = [x[1] for x in cache_files if x[0] in ['N', 'A']]
 424     rm_files =  [x[1] for x in cache_files if x[0] in ['D']]
 425     m_files =   [x[1] for x in cache_files if x[0] in ['M']]
 426
 427     if add_files and __run('git-update-index --add --', add_files) != 0:
 428         raise GitException, 'Failed git-update-index --add'
 429     if rm_files and __run('git-update-index --force-remove --', rm_files) != 0:
 430         raise GitException, 'Failed git-update-index --rm'
 431     if m_files and __run('git-update-index --', m_files) != 0:
 432         raise GitException, 'Failed git-update-index'
 433
 434     return True
 435
 436 def commit(message, files = None, parents = None, allowempty = False,
 437            cache_update = True, tree_id = None,
 438            author_name = None, author_email = None, author_date = None,
 439            committer_name = None, committer_email = None):
 440     """Commit the current tree to repository
 441     """
 442     if not files:
 443         files = []
 444     if not parents:
 445         parents = []
 446
 447     # Get the tree status
 448     if cache_update and parents != []:
 449         changes = update_cache(files)
 450         if not changes and not allowempty:
 451             raise GitException, 'No changes to commit'
 452
 453     # get the commit message
 454     if not message:
 455         message = '\n'
 456     elif message[-1:] != '\n':
 457         message += '\n'
 458
 459     must_switch = True
 460     # write the index to repository
 461     if tree_id == None:
 462         tree_id = _output_one_line('git-write-tree')
 463     else:
 464         must_switch = False
 465
 466     # the commit
 467     cmd = ''
 468     if author_name:
 469         cmd += 'GIT_AUTHOR_NAME="%s" ' % author_name
 470     if author_email:
 471         cmd += 'GIT_AUTHOR_EMAIL="%s" ' % author_email
 472     if author_date:
 473         cmd += 'GIT_AUTHOR_DATE="%s" ' % author_date
 474     if committer_name:
 475         cmd += 'GIT_COMMITTER_NAME="%s" ' % committer_name
 476     if committer_email:
 477         cmd += 'GIT_COMMITTER_EMAIL="%s" ' % committer_email
 478     cmd += 'git-commit-tree %s' % tree_id
 479
 480     # get the parents
 481     for p in parents:
 482         cmd += ' -p %s' % p
 483
 484     commit_id = _output_one_line(cmd, message)
 485     if must_switch:
 486         __set_head(commit_id)
 487
 488     return commit_id
 489
 490 def apply_diff(rev1, rev2, check_index = True, files = None):
 491     """Apply the diff between rev1 and rev2 onto the current
 492     index. This function doesn't need to raise an exception since it
 493     is only used for fast-pushing a patch. If this operation fails,
 494     the pushing would fall back to the three-way merge.
 495     """
 496     if check_index:
 497         index_opt = '--index'
 498     else:
 499         index_opt = ''
 500
 501     if not files:
 502         files = []
 503
 504     diff_str = diff(files, rev1, rev2)
 505     if diff_str:
 506         try:
 507             _input_str('git-apply %s' % index_opt, diff_str)
 508         except GitException:
 509             return False
 510
 511     return True
 512
 513 def merge(base, head1, head2):
 514     """Perform a 3-way merge between base, head1 and head2 into the
 515     local tree
 516     """
 517     refresh_index()
 518
 519     try:
 520         # use _output() to mask the verbose prints of the tool
 521         _output('git-merge-recursive %s -- %s %s' % (base, head1, head2))
 522     except GitException:
 523         pass
 524
 525     # check the index for unmerged entries
 526     files = {}
 527     stages_re = re.compile('^([0-7]+) ([0-9a-f]{40}) ([1-3])\t(.*)$', re.S)
 528
 529     for line in _output('git-ls-files --unmerged --stage -z').split('\0'):
 530         if not line:
 531             continue
 532
 533         mode, hash, stage, path = stages_re.findall(line)[0]
 534
 535         if not path in files:
 536             files[path] = {}
 537             files[path]['1'] = ('', '')
 538             files[path]['2'] = ('', '')
 539             files[path]['3'] = ('', '')
 540
 541         files[path][stage] = (mode, hash)
 542
 543     # merge the unmerged files
 544     errors = False
 545     for path in files:
 546         stages = files[path]
 547         if gitmergeonefile.merge(stages['1'][1], stages['2'][1],
 548                                  stages['3'][1], path, stages['1'][0],
 549                                  stages['2'][0], stages['3'][0]) != 0:
 550             errors = True
 551
 552     if errors:
 553         raise GitException, 'GIT index merging failed (possible conflicts)'
 554
 555 def status(files = None, modified = False, new = False, deleted = False,
 556            conflict = False, unknown = False, noexclude = False):
 557     """Show the tree status
 558     """
 559     if not files:
 560         files = []
 561
 562     cache_files = __tree_status(files, unknown = True, noexclude = noexclude)
 563     all = not (modified or new or deleted or conflict or unknown)
 564
 565     if not all:
 566         filestat = []
 567         if modified:
 568             filestat.append('M')
 569         if new:
 570             filestat.append('A')
 571             filestat.append('N')
 572         if deleted:
 573             filestat.append('D')
 574         if conflict:
 575             filestat.append('C')
 576         if unknown:
 577             filestat.append('?')
 578         cache_files = [x for x in cache_files if x[0] in filestat]
 579
 580     for fs in cache_files:
 581         if all:
 582             print '%s %s' % (fs[0], fs[1])
 583         else:
 584             print '%s' % fs[1]
 585
 586 def diff(files = None, rev1 = 'HEAD', rev2 = None, out_fd = None):
 587     """Show the diff between rev1 and rev2
 588     """
 589     if not files:
 590         files = []
 591
 592     if rev1 and rev2:
 593         diff_str = _output(['git-diff-tree', '-p', rev1, rev2, '--'] + files)
 594     elif rev1 or rev2:
 595         refresh_index()
 596         if rev2:
 597             diff_str = _output(['git-diff-index', '-p', '-R', rev2, '--'] + files)
 598         else:
 599             diff_str = _output(['git-diff-index', '-p', rev1, '--'] + files)
 600     else:
 601         diff_str = ''
 602
 603     if out_fd:
 604         out_fd.write(diff_str)
 605     else:
 606         return diff_str
 607
 608 def diffstat(files = None, rev1 = 'HEAD', rev2 = None):
 609     """Return the diffstat between rev1 and rev2
 610     """
 611     if not files:
 612         files = []
 613
 614     p=popen2.Popen3('git-apply --stat')
 615     diff(files, rev1, rev2, p.tochild)
 616     p.tochild.close()
 617     diff_str = p.fromchild.read().rstrip()
 618     if p.wait():
 619         raise GitException, 'git.diffstat failed'
 620     return diff_str
 621
 622 def files(rev1, rev2):
 623     """Return the files modified between rev1 and rev2
 624     """
 625
 626     result = ''
 627     for line in _output_lines('git-diff-tree -r %s %s' % (rev1, rev2)):
 628         result += '%s %s\n' % tuple(line.rstrip().split(' ',4)[-1].split('\t',1))
 629
 630     return result.rstrip()
 631
 632 def barefiles(rev1, rev2):
 633     """Return the files modified between rev1 and rev2, without status info
 634     """
 635
 636     result = ''
 637     for line in _output_lines('git-diff-tree -r %s %s' % (rev1, rev2)):
 638         result += '%s\n' % line.rstrip().split(' ',4)[-1].split('\t',1)[-1]
 639
 640     return result.rstrip()
 641
 642 def pretty_commit(commit_id = 'HEAD'):
 643     """Return a given commit (log + diff)
 644     """
 645     return _output(['git-diff-tree', '--cc', '--always', '--pretty', '-r',
 646                     commit_id])
 647
 648 def checkout(files = None, tree_id = None, force = False):
 649     """Check out the given or all files
 650     """
 651     if not files:
 652         files = []
 653
 654     if tree_id and __run('git-read-tree --reset', [tree_id]) != 0:
 655         raise GitException, 'Failed git-read-tree --reset %s' % tree_id
 656
 657     checkout_cmd = 'git-checkout-index -q -u'
 658     if force:
 659         checkout_cmd += ' -f'
 660     if len(files) == 0:
 661         checkout_cmd += ' -a'
 662     else:
 663         checkout_cmd += ' --'
 664
 665     if __run(checkout_cmd, files) != 0:
 666         raise GitException, 'Failed git-checkout-index'
 667
 668 def switch(tree_id, keep = False):
 669     """Switch the tree to the given id
 670     """
 671     if not keep:
 672         refresh_index()
 673         if __run('git-read-tree -u -m', [get_head(), tree_id]) != 0:
 674             raise GitException, 'git-read-tree failed (local changes maybe?)'
 675
 676     __set_head(tree_id)
 677
 678 def reset(files = None, tree_id = None, check_out = True):
 679     """Revert the tree changes relative to the given tree_id. It removes
 680     any local changes
 681     """
 682     if not tree_id:
 683         tree_id = get_head()
 684
 685     if check_out:
 686         cache_files = __tree_status(files, tree_id)
 687         # files which were added but need to be removed
 688         rm_files =  [x[1] for x in cache_files if x[0] in ['A']]
 689
 690         checkout(files, tree_id, True)
 691         # checkout doesn't remove files
 692         map(os.remove, rm_files)
 693
 694     # if the reset refers to the whole tree, switch the HEAD as well
 695     if not files:
 696         __set_head(tree_id)
 697
 698 def pull(repository = 'origin', refspec = None):
 699     """Pull changes from the remote repository. At the moment, just
 700     use the 'git-pull' command
 701     """
 702     # 'git-pull' updates the HEAD
 703     __clear_head_cache()
 704
 705     args = [repository]
 706     if refspec:
 707         args.append(refspec)
 708
 709     if __run(config.get('stgit', 'pullcmd'), args) != 0:
 710         raise GitException, 'Failed "git-pull %s"' % repository
 711
 712 def repack():
 713     """Repack all objects into a single pack
 714     """
 715     __run('git-repack -a -d -f')
 716
 717 def apply_patch(filename = None, diff = None, base = None,
 718                 fail_dump = True):
 719     """Apply a patch onto the current or given index. There must not
 720     be any local changes in the tree, otherwise the command fails
 721     """
 722     if base:
 723         orig_head = get_head()
 724         switch(base)
 725     else:
 726         refresh_index()
 727
 728     if diff is None:
 729         if filename:
 730             f = file(filename)
 731         else:
 732             f = sys.stdin
 733         diff = f.read()
 734         if filename:
 735             f.close()
 736
 737     try:
 738         _input_str('git-apply --index', diff)
 739     except GitException:
 740         if base:
 741             switch(orig_head)
 742         if fail_dump:
 743             # write the failed diff to a file
 744             f = file('.stgit-failed.patch', 'w+')
 745             f.write(diff)
 746             f.close()
 747
 748         raise
 749
 750     if base:
 751         top = commit(message = 'temporary commit used for applying a patch',
 752                      parents = [base])
 753         switch(orig_head)
 754         merge(base, orig_head, top)
 755
 756 def clone(repository, local_dir):
 757     """Clone a remote repository. At the moment, just use the
 758     'git-clone' script
 759     """
 760     if __run('git-clone', [repository, local_dir]) != 0:
 761         raise GitException, 'Failed "git-clone %s %s"' \
 762               % (repository, local_dir)
 763
 764 def modifying_revs(files, base_rev):
 765     """Return the revisions from the list modifying the given files
 766     """
 767     cmd = ['git-rev-list', '%s..' % base_rev, '--']
 768     revs = [line.strip() for line in _output_lines(cmd + files)]
 769
 770     return revs