chiark - git - mdw - stgit/blob - stgit/stack.py

   1 """Basic quilt-like functionality
   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
  22
  23 from stgit.utils import *
  24 from stgit import git
  25 from stgit.config import config
  26
  27
  28 # stack exception class
  29 class StackException(Exception):
  30     pass
  31
  32 class FilterUntil:
  33     def __init__(self):
  34         self.should_print = True
  35     def __call__(self, x, until_test, prefix):
  36         if until_test(x):
  37             self.should_print = False
  38         if self.should_print:
  39             return x[0:len(prefix)] != prefix
  40         return False
  41
  42 #
  43 # Functions
  44 #
  45 __comment_prefix = 'STG:'
  46 __patch_prefix = 'STG_PATCH:'
  47
  48 def __clean_comments(f):
  49     """Removes lines marked for status in a commit file
  50     """
  51     f.seek(0)
  52
  53     # remove status-prefixed lines
  54     lines = f.readlines()
  55
  56     patch_filter = FilterUntil()
  57     until_test = lambda t: t == (__patch_prefix + '\n')
  58     lines = [l for l in lines if patch_filter(l, until_test, __comment_prefix)]
  59
  60     # remove empty lines at the end
  61     while len(lines) != 0 and lines[-1] == '\n':
  62         del lines[-1]
  63
  64     f.seek(0); f.truncate()
  65     f.writelines(lines)
  66
  67 def edit_file(series, line, comment, show_patch = True):
  68     fname = '.stgit.msg'
  69     tmpl = os.path.join(git.get_base_dir(), 'patchdescr.tmpl')
  70
  71     f = file(fname, 'w+')
  72     if line:
  73         print >> f, line
  74     elif os.path.isfile(tmpl):
  75         print >> f, file(tmpl).read().rstrip()
  76     else:
  77         print >> f
  78     print >> f, __comment_prefix, comment
  79     print >> f, __comment_prefix, \
  80           'Lines prefixed with "%s" will be automatically removed.' \
  81           % __comment_prefix
  82     print >> f, __comment_prefix, \
  83           'Trailing empty lines will be automatically removed.'
  84
  85     if show_patch:
  86        print >> f, __patch_prefix
  87        # series.get_patch(series.get_current()).get_top()
  88        git.diff([], series.get_patch(series.get_current()).get_bottom(), None, f)
  89
  90     #Vim modeline must be near the end.
  91     print >> f, __comment_prefix, 'vi: set textwidth=75 filetype=diff nobackup:'
  92     f.close()
  93
  94     # the editor
  95     if config.has_option('stgit', 'editor'):
  96         editor = config.get('stgit', 'editor')
  97     elif 'EDITOR' in os.environ:
  98         editor = os.environ['EDITOR']
  99     else:
 100         editor = 'vi'
 101     editor += ' %s' % fname
 102
 103     print 'Invoking the editor: "%s"...' % editor,
 104     sys.stdout.flush()
 105     print 'done (exit code: %d)' % os.system(editor)
 106
 107     f = file(fname, 'r+')
 108
 109     __clean_comments(f)
 110     f.seek(0)
 111     result = f.read()
 112
 113     f.close()
 114     os.remove(fname)
 115
 116     return result
 117
 118 #
 119 # Classes
 120 #
 121
 122 class Patch:
 123     """Basic patch implementation
 124     """
 125     def __init__(self, name, series_dir, refs_dir):
 126         self.__series_dir = series_dir
 127         self.__name = name
 128         self.__dir = os.path.join(self.__series_dir, self.__name)
 129         self.__refs_dir = refs_dir
 130         self.__top_ref_file = os.path.join(self.__refs_dir, self.__name)
 131
 132     def create(self):
 133         os.mkdir(self.__dir)
 134         create_empty_file(os.path.join(self.__dir, 'bottom'))
 135         create_empty_file(os.path.join(self.__dir, 'top'))
 136
 137     def delete(self):
 138         for f in os.listdir(self.__dir):
 139             os.remove(os.path.join(self.__dir, f))
 140         os.rmdir(self.__dir)
 141         os.remove(self.__top_ref_file)
 142
 143     def get_name(self):
 144         return self.__name
 145
 146     def rename(self, newname):
 147         olddir = self.__dir
 148         old_ref_file = self.__top_ref_file
 149         self.__name = newname
 150         self.__dir = os.path.join(self.__series_dir, self.__name)
 151         self.__top_ref_file = os.path.join(self.__refs_dir, self.__name)
 152
 153         os.rename(olddir, self.__dir)
 154         os.rename(old_ref_file, self.__top_ref_file)
 155
 156     def __update_top_ref(self, ref):
 157         write_string(self.__top_ref_file, ref)
 158
 159     def update_top_ref(self):
 160         top = self.get_top()
 161         if top:
 162             self.__update_top_ref(top)
 163
 164     def __get_field(self, name, multiline = False):
 165         id_file = os.path.join(self.__dir, name)
 166         if os.path.isfile(id_file):
 167             line = read_string(id_file, multiline)
 168             if line == '':
 169                 return None
 170             else:
 171                 return line
 172         else:
 173             return None
 174
 175     def __set_field(self, name, value, multiline = False):
 176         fname = os.path.join(self.__dir, name)
 177         if value and value != '':
 178             write_string(fname, value, multiline)
 179         elif os.path.isfile(fname):
 180             os.remove(fname)
 181
 182     def get_old_bottom(self):
 183         return self.__get_field('bottom.old')
 184
 185     def get_bottom(self):
 186         return self.__get_field('bottom')
 187
 188     def set_bottom(self, value, backup = False):
 189         if backup:
 190             curr = self.__get_field('bottom')
 191             if curr != value:
 192                 self.__set_field('bottom.old', curr)
 193             else:
 194                 self.__set_field('bottom.old', None)
 195         self.__set_field('bottom', value)
 196
 197     def get_old_top(self):
 198         return self.__get_field('top.old')
 199
 200     def get_top(self):
 201         return self.__get_field('top')
 202
 203     def set_top(self, value, backup = False):
 204         if backup:
 205             curr = self.__get_field('top')
 206             if curr != value:
 207                 self.__set_field('top.old', curr)
 208             else:
 209                 self.__set_field('top.old', None)
 210         self.__set_field('top', value)
 211         self.__update_top_ref(value)
 212
 213     def restore_old_boundaries(self):
 214         bottom = self.__get_field('bottom.old')
 215         top = self.__get_field('top.old')
 216
 217         if top and bottom:
 218             self.__set_field('bottom', bottom)
 219             self.__set_field('top', top)
 220             self.__update_top_ref(top)
 221             return True
 222         else:
 223             return False
 224
 225     def get_description(self):
 226         return self.__get_field('description', True)
 227
 228     def set_description(self, line):
 229         self.__set_field('description', line, True)
 230
 231     def get_authname(self):
 232         return self.__get_field('authname')
 233
 234     def set_authname(self, name):
 235         if not name:
 236             if config.has_option('stgit', 'authname'):
 237                 name = config.get('stgit', 'authname')
 238             elif 'GIT_AUTHOR_NAME' in os.environ:
 239                 name = os.environ['GIT_AUTHOR_NAME']
 240         self.__set_field('authname', name)
 241
 242     def get_authemail(self):
 243         return self.__get_field('authemail')
 244
 245     def set_authemail(self, address):
 246         if not address:
 247             if config.has_option('stgit', 'authemail'):
 248                 address = config.get('stgit', 'authemail')
 249             elif 'GIT_AUTHOR_EMAIL' in os.environ:
 250                 address = os.environ['GIT_AUTHOR_EMAIL']
 251         self.__set_field('authemail', address)
 252
 253     def get_authdate(self):
 254         return self.__get_field('authdate')
 255
 256     def set_authdate(self, date):
 257         if not date and 'GIT_AUTHOR_DATE' in os.environ:
 258             date = os.environ['GIT_AUTHOR_DATE']
 259         self.__set_field('authdate', date)
 260
 261     def get_commname(self):
 262         return self.__get_field('commname')
 263
 264     def set_commname(self, name):
 265         if not name:
 266             if config.has_option('stgit', 'commname'):
 267                 name = config.get('stgit', 'commname')
 268             elif 'GIT_COMMITTER_NAME' in os.environ:
 269                 name = os.environ['GIT_COMMITTER_NAME']
 270         self.__set_field('commname', name)
 271
 272     def get_commemail(self):
 273         return self.__get_field('commemail')
 274
 275     def set_commemail(self, address):
 276         if not address:
 277             if config.has_option('stgit', 'commemail'):
 278                 address = config.get('stgit', 'commemail')
 279             elif 'GIT_COMMITTER_EMAIL' in os.environ:
 280                 address = os.environ['GIT_COMMITTER_EMAIL']
 281         self.__set_field('commemail', address)
 282
 283
 284 class Series:
 285     """Class including the operations on series
 286     """
 287     def __init__(self, name = None):
 288         """Takes a series name as the parameter.
 289         """
 290         try:
 291             if name:
 292                 self.__name = name
 293             else:
 294                 self.__name = git.get_head_file()
 295             self.__base_dir = git.get_base_dir()
 296         except git.GitException, ex:
 297             raise StackException, 'GIT tree not initialised: %s' % ex
 298
 299         self.__series_dir = os.path.join(self.__base_dir, 'patches',
 300                                          self.__name)
 301         self.__refs_dir = os.path.join(self.__base_dir, 'refs', 'patches',
 302                                        self.__name)
 303         self.__base_file = os.path.join(self.__base_dir, 'refs', 'bases',
 304                                         self.__name)
 305
 306         self.__applied_file = os.path.join(self.__series_dir, 'applied')
 307         self.__unapplied_file = os.path.join(self.__series_dir, 'unapplied')
 308         self.__current_file = os.path.join(self.__series_dir, 'current')
 309         self.__descr_file = os.path.join(self.__series_dir, 'description')
 310
 311         # where this series keeps its patches
 312         self.__patch_dir = os.path.join(self.__series_dir, 'patches')
 313         if not os.path.isdir(self.__patch_dir):
 314             self.__patch_dir = self.__series_dir
 315
 316         # if no __refs_dir, create and populate it (upgrade old repositories)
 317         if self.is_initialised() and not os.path.isdir(self.__refs_dir):
 318             os.makedirs(self.__refs_dir)
 319             for patch in self.get_applied() + self.get_unapplied():
 320                 self.get_patch(patch).update_top_ref()
 321
 322     def get_branch(self):
 323         """Return the branch name for the Series object
 324         """
 325         return self.__name
 326
 327     def __set_current(self, name):
 328         """Sets the topmost patch
 329         """
 330         if name:
 331             write_string(self.__current_file, name)
 332         else:
 333             create_empty_file(self.__current_file)
 334
 335     def get_patch(self, name):
 336         """Return a Patch object for the given name
 337         """
 338         return Patch(name, self.__patch_dir, self.__refs_dir)
 339
 340     def get_current(self):
 341         """Return a Patch object representing the topmost patch
 342         """
 343         if os.path.isfile(self.__current_file):
 344             name = read_string(self.__current_file)
 345         else:
 346             return None
 347         if name == '':
 348             return None
 349         else:
 350             return name
 351
 352     def get_applied(self):
 353         if not os.path.isfile(self.__applied_file):
 354             raise StackException, 'Branch "%s" not initialised' % self.__name
 355         f = file(self.__applied_file)
 356         names = [line.strip() for line in f.readlines()]
 357         f.close()
 358         return names
 359
 360     def get_unapplied(self):
 361         if not os.path.isfile(self.__unapplied_file):
 362             raise StackException, 'Branch "%s" not initialised' % self.__name
 363         f = file(self.__unapplied_file)
 364         names = [line.strip() for line in f.readlines()]
 365         f.close()
 366         return names
 367
 368     def get_base_file(self):
 369         self.__begin_stack_check()
 370         return self.__base_file
 371
 372     def get_protected(self):
 373         return os.path.isfile(os.path.join(self.__series_dir, 'protected'))
 374
 375     def protect(self):
 376         protect_file = os.path.join(self.__series_dir, 'protected')
 377         if not os.path.isfile(protect_file):
 378             create_empty_file(protect_file)
 379
 380     def unprotect(self):
 381         protect_file = os.path.join(self.__series_dir, 'protected')
 382         if os.path.isfile(protect_file):
 383             os.remove(protect_file)
 384
 385     def get_description(self):
 386         if os.path.isfile(self.__descr_file):
 387             return read_string(self.__descr_file)
 388         else:
 389             return ''
 390
 391     def __patch_is_current(self, patch):
 392         return patch.get_name() == read_string(self.__current_file)
 393
 394     def __patch_applied(self, name):
 395         """Return true if the patch exists in the applied list
 396         """
 397         return name in self.get_applied()
 398
 399     def __patch_unapplied(self, name):
 400         """Return true if the patch exists in the unapplied list
 401         """
 402         return name in self.get_unapplied()
 403
 404     def __begin_stack_check(self):
 405         """Save the current HEAD into .git/refs/heads/base if the stack
 406         is empty
 407         """
 408         if len(self.get_applied()) == 0:
 409             head = git.get_head()
 410             write_string(self.__base_file, head)
 411
 412     def __end_stack_check(self):
 413         """Remove .git/refs/heads/base if the stack is empty.
 414         This warning should never happen
 415         """
 416         if len(self.get_applied()) == 0 \
 417            and read_string(self.__base_file) != git.get_head():
 418             print 'Warning: stack empty but the HEAD and base are different'
 419
 420     def head_top_equal(self):
 421         """Return true if the head and the top are the same
 422         """
 423         crt = self.get_current()
 424         if not crt:
 425             # we don't care, no patches applied
 426             return True
 427         return git.get_head() == Patch(crt, self.__patch_dir,
 428                                        self.__refs_dir).get_top()
 429
 430     def is_initialised(self):
 431         """Checks if series is already initialised
 432         """
 433         return os.path.isdir(self.__patch_dir)
 434
 435     def init(self):
 436         """Initialises the stgit series
 437         """
 438         bases_dir = os.path.join(self.__base_dir, 'refs', 'bases')
 439
 440         if self.is_initialised():
 441             raise StackException, self.__patch_dir + ' already exists'
 442         os.makedirs(self.__patch_dir)
 443
 444         if not os.path.isdir(bases_dir):
 445             os.makedirs(bases_dir)
 446
 447         create_empty_file(self.__applied_file)
 448         create_empty_file(self.__unapplied_file)
 449         create_empty_file(self.__descr_file)
 450         os.makedirs(os.path.join(self.__series_dir, 'patches'))
 451         os.makedirs(self.__refs_dir)
 452         self.__begin_stack_check()
 453
 454     def convert(self):
 455         """Either convert to use a separate patch directory, or
 456         unconvert to place the patches in the same directory with
 457         series control files
 458         """
 459         if self.__patch_dir == self.__series_dir:
 460             print 'Converting old-style to new-style...',
 461             sys.stdout.flush()
 462
 463             self.__patch_dir = os.path.join(self.__series_dir, 'patches')
 464             os.makedirs(self.__patch_dir)
 465
 466             for p in self.get_applied() + self.get_unapplied():
 467                 src = os.path.join(self.__series_dir, p)
 468                 dest = os.path.join(self.__patch_dir, p)
 469                 os.rename(src, dest)
 470
 471             print 'done'
 472
 473         else:
 474             print 'Converting new-style to old-style...',
 475             sys.stdout.flush()
 476
 477             for p in self.get_applied() + self.get_unapplied():
 478                 src = os.path.join(self.__patch_dir, p)
 479                 dest = os.path.join(self.__series_dir, p)
 480                 os.rename(src, dest)
 481
 482             if not os.listdir(self.__patch_dir):
 483                 os.rmdir(self.__patch_dir)
 484                 print 'done'
 485             else:
 486                 print 'Patch directory %s is not empty.' % self.__name
 487
 488             self.__patch_dir = self.__series_dir
 489
 490     def rename(self, to_name):
 491         """Renames a series
 492         """
 493         to_stack = Series(to_name)
 494
 495         if to_stack.is_initialised():
 496             raise StackException, '"%s" already exists' % to_stack.get_branch()
 497         if os.path.exists(to_stack.__base_file):
 498             os.remove(to_stack.__base_file)
 499
 500         git.rename_branch(self.__name, to_name)
 501
 502         if os.path.isdir(self.__series_dir):
 503             os.rename(self.__series_dir, to_stack.__series_dir)
 504         if os.path.exists(self.__base_file):
 505             os.rename(self.__base_file, to_stack.__base_file)
 506
 507         self.__init__(to_name)
 508
 509     def clone(self, target_series):
 510         """Clones a series
 511         """
 512         base = read_string(self.get_base_file())
 513         git.create_branch(target_series, tree_id = base)
 514         Series(target_series).init()
 515         new_series = Series(target_series)
 516
 517         # generate an artificial description file
 518         write_string(new_series.__descr_file, 'clone of "%s"' % self.__name)
 519
 520         # clone self's entire series as unapplied patches
 521         patches = self.get_applied() + self.get_unapplied()
 522         patches.reverse()
 523         for p in patches:
 524             patch = self.get_patch(p)
 525             new_series.new_patch(p, message = patch.get_description(),
 526                                  can_edit = False, unapplied = True,
 527                                  bottom = patch.get_bottom(),
 528                                  top = patch.get_top(),
 529                                  author_name = patch.get_authname(),
 530                                  author_email = patch.get_authemail(),
 531                                  author_date = patch.get_authdate())
 532
 533         # fast forward the cloned series to self's top
 534         new_series.forward_patches(self.get_applied())
 535
 536     def delete(self, force = False):
 537         """Deletes an stgit series
 538         """
 539         if self.is_initialised():
 540             patches = self.get_unapplied() + self.get_applied()
 541             if not force and patches:
 542                 raise StackException, \
 543                       'Cannot delete: the series still contains patches'
 544             for p in patches:
 545                 Patch(p, self.__patch_dir, self.__refs_dir).delete()
 546
 547             if os.path.exists(self.__applied_file):
 548                 os.remove(self.__applied_file)
 549             if os.path.exists(self.__unapplied_file):
 550                 os.remove(self.__unapplied_file)
 551             if os.path.exists(self.__current_file):
 552                 os.remove(self.__current_file)
 553             if os.path.exists(self.__descr_file):
 554                 os.remove(self.__descr_file)
 555             if not os.listdir(self.__patch_dir):
 556                 os.rmdir(self.__patch_dir)
 557             else:
 558                 print 'Patch directory %s is not empty.' % self.__name
 559             if not os.listdir(self.__series_dir):
 560                 os.rmdir(self.__series_dir)
 561             else:
 562                 print 'Series directory %s is not empty.' % self.__name
 563             if not os.listdir(self.__refs_dir):
 564                 os.rmdir(self.__refs_dir)
 565             else:
 566                 print 'Refs directory %s is not empty.' % self.__refs_dir
 567
 568         if os.path.exists(self.__base_file):
 569             os.remove(self.__base_file)
 570
 571     def refresh_patch(self, files = None, message = None, edit = False,
 572                       show_patch = False,
 573                       cache_update = True,
 574                       author_name = None, author_email = None,
 575                       author_date = None,
 576                       committer_name = None, committer_email = None):
 577         """Generates a new commit for the given patch
 578         """
 579         name = self.get_current()
 580         if not name:
 581             raise StackException, 'No patches applied'
 582
 583         patch = Patch(name, self.__patch_dir, self.__refs_dir)
 584
 585         descr = patch.get_description()
 586         if not (message or descr):
 587             edit = True
 588             descr = ''
 589         elif message:
 590             descr = message
 591
 592         if not message and edit:
 593             descr = edit_file(self, descr.rstrip(), \
 594                               'Please edit the description for patch "%s" ' \
 595                               'above.' % name, show_patch)
 596
 597         if not author_name:
 598             author_name = patch.get_authname()
 599         if not author_email:
 600             author_email = patch.get_authemail()
 601         if not author_date:
 602             author_date = patch.get_authdate()
 603         if not committer_name:
 604             committer_name = patch.get_commname()
 605         if not committer_email:
 606             committer_email = patch.get_commemail()
 607
 608         commit_id = git.commit(files = files,
 609                                message = descr, parents = [patch.get_bottom()],
 610                                cache_update = cache_update,
 611                                allowempty = True,
 612                                author_name = author_name,
 613                                author_email = author_email,
 614                                author_date = author_date,
 615                                committer_name = committer_name,
 616                                committer_email = committer_email)
 617
 618         patch.set_top(commit_id)
 619         patch.set_description(descr)
 620         patch.set_authname(author_name)
 621         patch.set_authemail(author_email)
 622         patch.set_authdate(author_date)
 623         patch.set_commname(committer_name)
 624         patch.set_commemail(committer_email)
 625
 626         return commit_id
 627
 628     def new_patch(self, name, message = None, can_edit = True,
 629                   unapplied = False, show_patch = False,
 630                   top = None, bottom = None,
 631                   author_name = None, author_email = None, author_date = None,
 632                   committer_name = None, committer_email = None,
 633                   before_existing = False):
 634         """Creates a new patch
 635         """
 636         if self.__patch_applied(name) or self.__patch_unapplied(name):
 637             raise StackException, 'Patch "%s" already exists' % name
 638
 639         if not message and can_edit:
 640             descr = edit_file(self, None, \
 641                               'Please enter the description for patch "%s" ' \
 642                               'above.' % name, show_patch)
 643         else:
 644             descr = message
 645
 646         head = git.get_head()
 647
 648         self.__begin_stack_check()
 649
 650         patch = Patch(name, self.__patch_dir, self.__refs_dir)
 651         patch.create()
 652
 653         if bottom:
 654             patch.set_bottom(bottom)
 655         else:
 656             patch.set_bottom(head)
 657         if top:
 658             patch.set_top(top)
 659         else:
 660             patch.set_top(head)
 661
 662         patch.set_description(descr)
 663         patch.set_authname(author_name)
 664         patch.set_authemail(author_email)
 665         patch.set_authdate(author_date)
 666         patch.set_commname(committer_name)
 667         patch.set_commemail(committer_email)
 668
 669         if unapplied:
 670             patches = [patch.get_name()] + self.get_unapplied()
 671
 672             f = file(self.__unapplied_file, 'w+')
 673             f.writelines([line + '\n' for line in patches])
 674             f.close()
 675         else:
 676             if before_existing:
 677                 insert_string(self.__applied_file, patch.get_name())
 678                 if not self.get_current():
 679                     self.__set_current(name)
 680             else:
 681                 append_string(self.__applied_file, patch.get_name())
 682                 self.__set_current(name)
 683
 684     def delete_patch(self, name):
 685         """Deletes a patch
 686         """
 687         patch = Patch(name, self.__patch_dir, self.__refs_dir)
 688
 689         if self.__patch_is_current(patch):
 690             self.pop_patch(name)
 691         elif self.__patch_applied(name):
 692             raise StackException, 'Cannot remove an applied patch, "%s", ' \
 693                   'which is not current' % name
 694         elif not name in self.get_unapplied():
 695             raise StackException, 'Unknown patch "%s"' % name
 696
 697         patch.delete()
 698
 699         unapplied = self.get_unapplied()
 700         unapplied.remove(name)
 701         f = file(self.__unapplied_file, 'w+')
 702         f.writelines([line + '\n' for line in unapplied])
 703         f.close()
 704         self.__begin_stack_check()
 705
 706     def forward_patches(self, names):
 707         """Try to fast-forward an array of patches.
 708
 709         On return, patches in names[0:returned_value] have been pushed on the
 710         stack. Apply the rest with push_patch
 711         """
 712         unapplied = self.get_unapplied()
 713         self.__begin_stack_check()
 714
 715         forwarded = 0
 716         top = git.get_head()
 717
 718         for name in names:
 719             assert(name in unapplied)
 720
 721             patch = Patch(name, self.__patch_dir, self.__refs_dir)
 722
 723             head = top
 724             bottom = patch.get_bottom()
 725             top = patch.get_top()
 726
 727             # top != bottom always since we have a commit for each patch
 728             if head == bottom:
 729                 # reset the backup information
 730                 patch.set_bottom(head, backup = True)
 731                 patch.set_top(top, backup = True)
 732
 733             else:
 734                 head_tree = git.get_commit(head).get_tree()
 735                 bottom_tree = git.get_commit(bottom).get_tree()
 736                 if head_tree == bottom_tree:
 737                     # We must just reparent this patch and create a new commit
 738                     # for it
 739                     descr = patch.get_description()
 740                     author_name = patch.get_authname()
 741                     author_email = patch.get_authemail()
 742                     author_date = patch.get_authdate()
 743                     committer_name = patch.get_commname()
 744                     committer_email = patch.get_commemail()
 745
 746                     top_tree = git.get_commit(top).get_tree()
 747
 748                     top = git.commit(message = descr, parents = [head],
 749                                      cache_update = False,
 750                                      tree_id = top_tree,
 751                                      allowempty = True,
 752                                      author_name = author_name,
 753                                      author_email = author_email,
 754                                      author_date = author_date,
 755                                      committer_name = committer_name,
 756                                      committer_email = committer_email)
 757
 758                     patch.set_bottom(head, backup = True)
 759                     patch.set_top(top, backup = True)
 760                 else:
 761                     top = head
 762                     # stop the fast-forwarding, must do a real merge
 763                     break
 764
 765             forwarded+=1
 766             unapplied.remove(name)
 767
 768         if forwarded == 0:
 769             return 0
 770
 771         git.switch(top)
 772
 773         append_strings(self.__applied_file, names[0:forwarded])
 774
 775         f = file(self.__unapplied_file, 'w+')
 776         f.writelines([line + '\n' for line in unapplied])
 777         f.close()
 778
 779         self.__set_current(name)
 780
 781         return forwarded
 782
 783     def merged_patches(self, names):
 784         """Test which patches were merged upstream by reverse-applying
 785         them in reverse order. The function returns the list of
 786         patches detected to have been applied. The state of the tree
 787         is restored to the original one
 788         """
 789         patches = [Patch(name, self.__patch_dir, self.__refs_dir)
 790                    for name in names]
 791         patches.reverse()
 792
 793         merged = []
 794         for p in patches:
 795             if git.apply_diff(p.get_top(), p.get_bottom(), False):
 796                 merged.append(p.get_name())
 797         merged.reverse()
 798
 799         git.reset()
 800
 801         return merged
 802
 803     def push_patch(self, name, empty = False):
 804         """Pushes a patch on the stack
 805         """
 806         unapplied = self.get_unapplied()
 807         assert(name in unapplied)
 808
 809         self.__begin_stack_check()
 810
 811         patch = Patch(name, self.__patch_dir, self.__refs_dir)
 812
 813         head = git.get_head()
 814         bottom = patch.get_bottom()
 815         top = patch.get_top()
 816
 817         ex = None
 818         modified = False
 819
 820         # top != bottom always since we have a commit for each patch
 821         if empty:
 822             # just make an empty patch (top = bottom = HEAD). This
 823             # option is useful to allow undoing already merged
 824             # patches. The top is updated by refresh_patch since we
 825             # need an empty commit
 826             patch.set_bottom(head, backup = True)
 827             patch.set_top(head, backup = True)
 828             modified = True
 829         elif head == bottom:
 830             # reset the backup information
 831             patch.set_bottom(bottom, backup = True)
 832             patch.set_top(top, backup = True)
 833
 834             git.switch(top)
 835         else:
 836             # new patch needs to be refreshed.
 837             # The current patch is empty after merge.
 838             patch.set_bottom(head, backup = True)
 839             patch.set_top(head, backup = True)
 840
 841             # Try the fast applying first. If this fails, fall back to the
 842             # three-way merge
 843             if not git.apply_diff(bottom, top):
 844                 # if git.apply_diff() fails, the patch requires a diff3
 845                 # merge and can be reported as modified
 846                 modified = True
 847
 848                 # merge can fail but the patch needs to be pushed
 849                 try:
 850                     git.merge(bottom, head, top)
 851                 except git.GitException, ex:
 852                     print >> sys.stderr, \
 853                           'The merge failed during "push". ' \
 854                           'Use "refresh" after fixing the conflicts'
 855
 856         append_string(self.__applied_file, name)
 857
 858         unapplied.remove(name)
 859         f = file(self.__unapplied_file, 'w+')
 860         f.writelines([line + '\n' for line in unapplied])
 861         f.close()
 862
 863         self.__set_current(name)
 864
 865         # head == bottom case doesn't need to refresh the patch
 866         if empty or head != bottom:
 867             if not ex:
 868                 # if the merge was OK and no conflicts, just refresh the patch
 869                 # The GIT cache was already updated by the merge operation
 870                 self.refresh_patch(cache_update = False)
 871             else:
 872                 raise StackException, str(ex)
 873
 874         return modified
 875
 876     def undo_push(self):
 877         name = self.get_current()
 878         assert(name)
 879
 880         patch = Patch(name, self.__patch_dir, self.__refs_dir)
 881         git.reset()
 882         self.pop_patch(name)
 883         return patch.restore_old_boundaries()
 884
 885     def pop_patch(self, name):
 886         """Pops the top patch from the stack
 887         """
 888         applied = self.get_applied()
 889         applied.reverse()
 890         assert(name in applied)
 891
 892         patch = Patch(name, self.__patch_dir, self.__refs_dir)
 893
 894         git.switch(patch.get_bottom())
 895
 896         # save the new applied list
 897         idx = applied.index(name) + 1
 898
 899         popped = applied[:idx]
 900         popped.reverse()
 901         unapplied = popped + self.get_unapplied()
 902
 903         f = file(self.__unapplied_file, 'w+')
 904         f.writelines([line + '\n' for line in unapplied])
 905         f.close()
 906
 907         del applied[:idx]
 908         applied.reverse()
 909
 910         f = file(self.__applied_file, 'w+')
 911         f.writelines([line + '\n' for line in applied])
 912         f.close()
 913
 914         if applied == []:
 915             self.__set_current(None)
 916         else:
 917             self.__set_current(applied[-1])
 918
 919         self.__end_stack_check()
 920
 921     def empty_patch(self, name):
 922         """Returns True if the patch is empty
 923         """
 924         patch = Patch(name, self.__patch_dir, self.__refs_dir)
 925         bottom = patch.get_bottom()
 926         top = patch.get_top()
 927
 928         if bottom == top:
 929             return True
 930         elif git.get_commit(top).get_tree() \
 931                  == git.get_commit(bottom).get_tree():
 932             return True
 933
 934         return False
 935
 936     def rename_patch(self, oldname, newname):
 937         applied = self.get_applied()
 938         unapplied = self.get_unapplied()
 939
 940         if oldname == newname:
 941             raise StackException, '"To" name and "from" name are the same'
 942
 943         if newname in applied or newname in unapplied:
 944             raise StackException, 'Patch "%s" already exists' % newname
 945
 946         if oldname in unapplied:
 947             Patch(oldname, self.__patch_dir, self.__refs_dir).rename(newname)
 948             unapplied[unapplied.index(oldname)] = newname
 949
 950             f = file(self.__unapplied_file, 'w+')
 951             f.writelines([line + '\n' for line in unapplied])
 952             f.close()
 953         elif oldname in applied:
 954             Patch(oldname, self.__patch_dir, self.__refs_dir).rename(newname)
 955             if oldname == self.get_current():
 956                 self.__set_current(newname)
 957
 958             applied[applied.index(oldname)] = newname
 959
 960             f = file(self.__applied_file, 'w+')
 961             f.writelines([line + '\n' for line in applied])
 962             f.close()
 963         else:
 964             raise StackException, 'Unknown patch "%s"' % oldname