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):
 126         self.__series_dir = series_dir
 127         self.__name = name
 128         self.__dir = os.path.join(self.__series_dir, self.__name)
 129
 130     def create(self):
 131         os.mkdir(self.__dir)
 132         create_empty_file(os.path.join(self.__dir, 'bottom'))
 133         create_empty_file(os.path.join(self.__dir, 'top'))
 134
 135     def delete(self):
 136         for f in os.listdir(self.__dir):
 137             os.remove(os.path.join(self.__dir, f))
 138         os.rmdir(self.__dir)
 139
 140     def get_name(self):
 141         return self.__name
 142
 143     def rename(self, newname):
 144         olddir = self.__dir
 145         self.__name = newname
 146         self.__dir = os.path.join(self.__series_dir, self.__name)
 147
 148         os.rename(olddir, self.__dir)
 149
 150     def __get_field(self, name, multiline = False):
 151         id_file = os.path.join(self.__dir, name)
 152         if os.path.isfile(id_file):
 153             line = read_string(id_file, multiline)
 154             if line == '':
 155                 return None
 156             else:
 157                 return line
 158         else:
 159             return None
 160
 161     def __set_field(self, name, value, multiline = False):
 162         fname = os.path.join(self.__dir, name)
 163         if value and value != '':
 164             write_string(fname, value, multiline)
 165         elif os.path.isfile(fname):
 166             os.remove(fname)
 167
 168     def get_old_bottom(self):
 169         return self.__get_field('bottom.old')
 170
 171     def get_bottom(self):
 172         return self.__get_field('bottom')
 173
 174     def set_bottom(self, value, backup = False):
 175         if backup:
 176             curr = self.__get_field('bottom')
 177             if curr != value:
 178                 self.__set_field('bottom.old', curr)
 179             else:
 180                 self.__set_field('bottom.old', None)
 181         self.__set_field('bottom', value)
 182
 183     def get_old_top(self):
 184         return self.__get_field('top.old')
 185
 186     def get_top(self):
 187         return self.__get_field('top')
 188
 189     def set_top(self, value, backup = False):
 190         if backup:
 191             curr = self.__get_field('top')
 192             if curr != value:
 193                 self.__set_field('top.old', curr)
 194             else:
 195                 self.__set_field('top.old', None)
 196         self.__set_field('top', value)
 197
 198     def restore_old_boundaries(self):
 199         bottom = self.__get_field('bottom.old')
 200         top = self.__get_field('top.old')
 201
 202         if top and bottom:
 203             self.__set_field('bottom', bottom)
 204             self.__set_field('top', top)
 205             return True
 206         else:
 207             return False
 208
 209     def get_description(self):
 210         return self.__get_field('description', True)
 211
 212     def set_description(self, line):
 213         self.__set_field('description', line, True)
 214
 215     def get_authname(self):
 216         return self.__get_field('authname')
 217
 218     def set_authname(self, name):
 219         if not name and config.has_option('stgit', 'authname'):
 220             name = config.get('stgit', 'authname')
 221         self.__set_field('authname', name)
 222
 223     def get_authemail(self):
 224         return self.__get_field('authemail')
 225
 226     def set_authemail(self, address):
 227         if not address and config.has_option('stgit', 'authemail'):
 228             address = config.get('stgit', 'authemail')
 229         self.__set_field('authemail', address)
 230
 231     def get_authdate(self):
 232         return self.__get_field('authdate')
 233
 234     def set_authdate(self, authdate):
 235         self.__set_field('authdate', authdate)
 236
 237     def get_commname(self):
 238         return self.__get_field('commname')
 239
 240     def set_commname(self, name):
 241         if not name and config.has_option('stgit', 'commname'):
 242             name = config.get('stgit', 'commname')
 243         self.__set_field('commname', name)
 244
 245     def get_commemail(self):
 246         return self.__get_field('commemail')
 247
 248     def set_commemail(self, address):
 249         if not address and config.has_option('stgit', 'commemail'):
 250             address = config.get('stgit', 'commemail')
 251         self.__set_field('commemail', address)
 252
 253
 254 class Series:
 255     """Class including the operations on series
 256     """
 257     def __init__(self, name = None):
 258         """Takes a series name as the parameter.
 259         """
 260         try:
 261             if name:
 262                 self.__name = name
 263             else:
 264                 self.__name = git.get_head_file()
 265             base_dir = git.get_base_dir()
 266         except git.GitException, ex:
 267             raise StackException, 'GIT tree not initialised: %s' % ex
 268
 269         self.__series_dir = os.path.join(base_dir, 'patches',
 270                                          self.__name)
 271         self.__base_file = os.path.join(base_dir, 'refs', 'bases',
 272                                         self.__name)
 273
 274         self.__applied_file = os.path.join(self.__series_dir, 'applied')
 275         self.__unapplied_file = os.path.join(self.__series_dir, 'unapplied')
 276         self.__current_file = os.path.join(self.__series_dir, 'current')
 277         self.__descr_file = os.path.join(self.__series_dir, 'description')
 278
 279         # where this series keeps its patches
 280         self.__patch_dir = os.path.join(self.__series_dir, 'patches')
 281         if not os.path.isdir(self.__patch_dir):
 282             self.__patch_dir = self.__series_dir
 283
 284     def get_branch(self):
 285         """Return the branch name for the Series object
 286         """
 287         return self.__name
 288
 289     def __set_current(self, name):
 290         """Sets the topmost patch
 291         """
 292         if name:
 293             write_string(self.__current_file, name)
 294         else:
 295             create_empty_file(self.__current_file)
 296
 297     def get_patch(self, name):
 298         """Return a Patch object for the given name
 299         """
 300         return Patch(name, self.__patch_dir)
 301
 302     def get_current(self):
 303         """Return a Patch object representing the topmost patch
 304         """
 305         if os.path.isfile(self.__current_file):
 306             name = read_string(self.__current_file)
 307         else:
 308             return None
 309         if name == '':
 310             return None
 311         else:
 312             return name
 313
 314     def get_applied(self):
 315         if not os.path.isfile(self.__applied_file):
 316             raise StackException, 'Branch "%s" not initialised' % self.__name
 317         f = file(self.__applied_file)
 318         names = [line.strip() for line in f.readlines()]
 319         f.close()
 320         return names
 321
 322     def get_unapplied(self):
 323         if not os.path.isfile(self.__unapplied_file):
 324             raise StackException, 'Branch "%s" not initialised' % self.__name
 325         f = file(self.__unapplied_file)
 326         names = [line.strip() for line in f.readlines()]
 327         f.close()
 328         return names
 329
 330     def get_base_file(self):
 331         return self.__base_file
 332
 333     def get_protected(self):
 334         return os.path.isfile(os.path.join(self.__series_dir, 'protected'))
 335
 336     def protect(self):
 337         protect_file = os.path.join(self.__series_dir, 'protected')
 338         if not os.path.isfile(protect_file):
 339             create_empty_file(protect_file)
 340
 341     def unprotect(self):
 342         protect_file = os.path.join(self.__series_dir, 'protected')
 343         if os.path.isfile(protect_file):
 344             os.remove(protect_file)
 345
 346     def get_description(self):
 347         if os.path.isfile(self.__descr_file):
 348             return read_string(self.__descr_file)
 349         else:
 350             return ''
 351
 352     def __patch_is_current(self, patch):
 353         return patch.get_name() == read_string(self.__current_file)
 354
 355     def __patch_applied(self, name):
 356         """Return true if the patch exists in the applied list
 357         """
 358         return name in self.get_applied()
 359
 360     def __patch_unapplied(self, name):
 361         """Return true if the patch exists in the unapplied list
 362         """
 363         return name in self.get_unapplied()
 364
 365     def __begin_stack_check(self):
 366         """Save the current HEAD into .git/refs/heads/base if the stack
 367         is empty
 368         """
 369         if len(self.get_applied()) == 0:
 370             head = git.get_head()
 371             write_string(self.__base_file, head)
 372
 373     def __end_stack_check(self):
 374         """Remove .git/refs/heads/base if the stack is empty.
 375         This warning should never happen
 376         """
 377         if len(self.get_applied()) == 0 \
 378            and read_string(self.__base_file) != git.get_head():
 379             print 'Warning: stack empty but the HEAD and base are different'
 380
 381     def head_top_equal(self):
 382         """Return true if the head and the top are the same
 383         """
 384         crt = self.get_current()
 385         if not crt:
 386             # we don't care, no patches applied
 387             return True
 388         return git.get_head() == Patch(crt, self.__patch_dir).get_top()
 389
 390     def is_initialised(self):
 391         """Checks if series is already initialised
 392         """
 393         return os.path.isdir(self.__patch_dir)
 394
 395     def init(self):
 396         """Initialises the stgit series
 397         """
 398         bases_dir = os.path.join(git.get_base_dir(), 'refs', 'bases')
 399
 400         if self.is_initialised():
 401             raise StackException, self.__patch_dir + ' already exists'
 402         os.makedirs(self.__patch_dir)
 403
 404         if not os.path.isdir(bases_dir):
 405             os.makedirs(bases_dir)
 406
 407         create_empty_file(self.__applied_file)
 408         create_empty_file(self.__unapplied_file)
 409         create_empty_file(self.__descr_file)
 410         os.makedirs(os.path.join(self.__series_dir, 'patches'))
 411         self.__begin_stack_check()
 412
 413     def convert(self):
 414         """Either convert to use a separate patch directory, or
 415         unconvert to place the patches in the same directory with
 416         series control files
 417         """
 418         if self.__patch_dir == self.__series_dir:
 419             print 'Converting old-style to new-style...',
 420             sys.stdout.flush()
 421
 422             self.__patch_dir = os.path.join(self.__series_dir, 'patches')
 423             os.makedirs(self.__patch_dir)
 424
 425             for p in self.get_applied() + self.get_unapplied():
 426                 src = os.path.join(self.__series_dir, p)
 427                 dest = os.path.join(self.__patch_dir, p)
 428                 os.rename(src, dest)
 429
 430             print 'done'
 431
 432         else:
 433             print 'Converting new-style to old-style...',
 434             sys.stdout.flush()
 435
 436             for p in self.get_applied() + self.get_unapplied():
 437                 src = os.path.join(self.__patch_dir, p)
 438                 dest = os.path.join(self.__series_dir, p)
 439                 os.rename(src, dest)
 440
 441             if not os.listdir(self.__patch_dir):
 442                 os.rmdir(self.__patch_dir)
 443                 print 'done'
 444             else:
 445                 print 'Patch directory %s is not empty.' % self.__name
 446
 447             self.__patch_dir = self.__series_dir
 448
 449     def rename(self, to_name):
 450         """Renames a series
 451         """
 452         to_stack = Series(to_name)
 453
 454         if to_stack.is_initialised():
 455             raise StackException, '"%s" already exists' % to_stack.get_branch()
 456         if os.path.exists(to_stack.__base_file):
 457             os.remove(to_stack.__base_file)
 458
 459         git.rename_branch(self.__name, to_name)
 460
 461         if os.path.isdir(self.__series_dir):
 462             os.rename(self.__series_dir, to_stack.__series_dir)
 463         if os.path.exists(self.__base_file):
 464             os.rename(self.__base_file, to_stack.__base_file)
 465
 466         self.__init__(to_name)
 467
 468     def clone(self, target_series):
 469         """Clones a series
 470         """
 471         base = read_string(self.get_base_file())
 472         git.create_branch(target_series, tree_id = base)
 473         Series(target_series).init()
 474         new_series = Series(target_series)
 475
 476         # generate an artificial description file
 477         write_string(new_series.__descr_file, 'clone of "%s"' % self.__name)
 478
 479         # clone self's entire series as unapplied patches
 480         patches = self.get_applied() + self.get_unapplied()
 481         patches.reverse()
 482         for p in patches:
 483             patch = self.get_patch(p)
 484             new_series.new_patch(p, message = patch.get_description(),
 485                                  can_edit = False, unapplied = True,
 486                                  bottom = patch.get_bottom(),
 487                                  top = patch.get_top(),
 488                                  author_name = patch.get_authname(),
 489                                  author_email = patch.get_authemail(),
 490                                  author_date = patch.get_authdate())
 491
 492         # fast forward the cloned series to self's top
 493         new_series.forward_patches(self.get_applied())
 494
 495     def delete(self, force = False):
 496         """Deletes an stgit series
 497         """
 498         if self.is_initialised():
 499             patches = self.get_unapplied() + self.get_applied()
 500             if not force and patches:
 501                 raise StackException, \
 502                       'Cannot delete: the series still contains patches'
 503             for p in patches:
 504                 Patch(p, self.__patch_dir).delete()
 505
 506             if os.path.exists(self.__applied_file):
 507                 os.remove(self.__applied_file)
 508             if os.path.exists(self.__unapplied_file):
 509                 os.remove(self.__unapplied_file)
 510             if os.path.exists(self.__current_file):
 511                 os.remove(self.__current_file)
 512             if os.path.exists(self.__descr_file):
 513                 os.remove(self.__descr_file)
 514             if not os.listdir(self.__patch_dir):
 515                 os.rmdir(self.__patch_dir)
 516             else:
 517                 print 'Patch directory %s is not empty.' % self.__name
 518             if not os.listdir(self.__series_dir):
 519                 os.rmdir(self.__series_dir)
 520             else:
 521                 print 'Series directory %s is not empty.' % self.__name
 522
 523         if os.path.exists(self.__base_file):
 524             os.remove(self.__base_file)
 525
 526     def refresh_patch(self, files = None, message = None, edit = False,
 527                       show_patch = False,
 528                       cache_update = True,
 529                       author_name = None, author_email = None,
 530                       author_date = None,
 531                       committer_name = None, committer_email = None):
 532         """Generates a new commit for the given patch
 533         """
 534         name = self.get_current()
 535         if not name:
 536             raise StackException, 'No patches applied'
 537
 538         patch = Patch(name, self.__patch_dir)
 539
 540         descr = patch.get_description()
 541         if not (message or descr):
 542             edit = True
 543             descr = ''
 544         elif message:
 545             descr = message
 546
 547         if not message and edit:
 548             descr = edit_file(self, descr.rstrip(), \
 549                               'Please edit the description for patch "%s" ' \
 550                               'above.' % name, show_patch)
 551
 552         if not author_name:
 553             author_name = patch.get_authname()
 554         if not author_email:
 555             author_email = patch.get_authemail()
 556         if not author_date:
 557             author_date = patch.get_authdate()
 558         if not committer_name:
 559             committer_name = patch.get_commname()
 560         if not committer_email:
 561             committer_email = patch.get_commemail()
 562
 563         commit_id = git.commit(files = files,
 564                                message = descr, parents = [patch.get_bottom()],
 565                                cache_update = cache_update,
 566                                allowempty = True,
 567                                author_name = author_name,
 568                                author_email = author_email,
 569                                author_date = author_date,
 570                                committer_name = committer_name,
 571                                committer_email = committer_email)
 572
 573         patch.set_top(commit_id)
 574         patch.set_description(descr)
 575         patch.set_authname(author_name)
 576         patch.set_authemail(author_email)
 577         patch.set_authdate(author_date)
 578         patch.set_commname(committer_name)
 579         patch.set_commemail(committer_email)
 580
 581         return commit_id
 582
 583     def new_patch(self, name, message = None, can_edit = True,
 584                   unapplied = False, show_patch = False,
 585                   top = None, bottom = None,
 586                   author_name = None, author_email = None, author_date = None,
 587                   committer_name = None, committer_email = None):
 588         """Creates a new patch
 589         """
 590         if self.__patch_applied(name) or self.__patch_unapplied(name):
 591             raise StackException, 'Patch "%s" already exists' % name
 592
 593         if not message and can_edit:
 594             descr = edit_file(self, None, \
 595                               'Please enter the description for patch "%s" ' \
 596                               'above.' % name, show_patch)
 597         else:
 598             descr = message
 599
 600         head = git.get_head()
 601
 602         self.__begin_stack_check()
 603
 604         patch = Patch(name, self.__patch_dir)
 605         patch.create()
 606
 607         if bottom:
 608             patch.set_bottom(bottom)
 609         else:
 610             patch.set_bottom(head)
 611         if top:
 612             patch.set_top(top)
 613         else:
 614             patch.set_top(head)
 615
 616         patch.set_description(descr)
 617         patch.set_authname(author_name)
 618         patch.set_authemail(author_email)
 619         patch.set_authdate(author_date)
 620         patch.set_commname(committer_name)
 621         patch.set_commemail(committer_email)
 622
 623         if unapplied:
 624             patches = [patch.get_name()] + self.get_unapplied()
 625
 626             f = file(self.__unapplied_file, 'w+')
 627             f.writelines([line + '\n' for line in patches])
 628             f.close()
 629         else:
 630             append_string(self.__applied_file, patch.get_name())
 631             self.__set_current(name)
 632
 633     def delete_patch(self, name):
 634         """Deletes a patch
 635         """
 636         patch = Patch(name, self.__patch_dir)
 637
 638         if self.__patch_is_current(patch):
 639             self.pop_patch(name)
 640         elif self.__patch_applied(name):
 641             raise StackException, 'Cannot remove an applied patch, "%s", ' \
 642                   'which is not current' % name
 643         elif not name in self.get_unapplied():
 644             raise StackException, 'Unknown patch "%s"' % name
 645
 646         patch.delete()
 647
 648         unapplied = self.get_unapplied()
 649         unapplied.remove(name)
 650         f = file(self.__unapplied_file, 'w+')
 651         f.writelines([line + '\n' for line in unapplied])
 652         f.close()
 653
 654     def forward_patches(self, names):
 655         """Try to fast-forward an array of patches.
 656
 657         On return, patches in names[0:returned_value] have been pushed on the
 658         stack. Apply the rest with push_patch
 659         """
 660         unapplied = self.get_unapplied()
 661         self.__begin_stack_check()
 662
 663         forwarded = 0
 664         top = git.get_head()
 665
 666         for name in names:
 667             assert(name in unapplied)
 668
 669             patch = Patch(name, self.__patch_dir)
 670
 671             head = top
 672             bottom = patch.get_bottom()
 673             top = patch.get_top()
 674
 675             # top != bottom always since we have a commit for each patch
 676             if head == bottom:
 677                 # reset the backup information
 678                 patch.set_bottom(head, backup = True)
 679                 patch.set_top(top, backup = True)
 680
 681             else:
 682                 head_tree = git.get_commit(head).get_tree()
 683                 bottom_tree = git.get_commit(bottom).get_tree()
 684                 if head_tree == bottom_tree:
 685                     # We must just reparent this patch and create a new commit
 686                     # for it
 687                     descr = patch.get_description()
 688                     author_name = patch.get_authname()
 689                     author_email = patch.get_authemail()
 690                     author_date = patch.get_authdate()
 691                     committer_name = patch.get_commname()
 692                     committer_email = patch.get_commemail()
 693
 694                     top_tree = git.get_commit(top).get_tree()
 695
 696                     top = git.commit(message = descr, parents = [head],
 697                                      cache_update = False,
 698                                      tree_id = top_tree,
 699                                      allowempty = True,
 700                                      author_name = author_name,
 701                                      author_email = author_email,
 702                                      author_date = author_date,
 703                                      committer_name = committer_name,
 704                                      committer_email = committer_email)
 705
 706                     patch.set_bottom(head, backup = True)
 707                     patch.set_top(top, backup = True)
 708                 else:
 709                     top = head
 710                     # stop the fast-forwarding, must do a real merge
 711                     break
 712
 713             forwarded+=1
 714             unapplied.remove(name)
 715
 716         if forwarded == 0:
 717             return 0
 718
 719         git.switch(top)
 720
 721         append_strings(self.__applied_file, names[0:forwarded])
 722
 723         f = file(self.__unapplied_file, 'w+')
 724         f.writelines([line + '\n' for line in unapplied])
 725         f.close()
 726
 727         self.__set_current(name)
 728
 729         return forwarded
 730
 731     def push_patch(self, name):
 732         """Pushes a patch on the stack
 733         """
 734         unapplied = self.get_unapplied()
 735         assert(name in unapplied)
 736
 737         self.__begin_stack_check()
 738
 739         patch = Patch(name, self.__patch_dir)
 740
 741         head = git.get_head()
 742         bottom = patch.get_bottom()
 743         top = patch.get_top()
 744
 745         ex = None
 746         modified = False
 747
 748         # top != bottom always since we have a commit for each patch
 749         if head == bottom:
 750             # reset the backup information
 751             patch.set_bottom(bottom, backup = True)
 752             patch.set_top(top, backup = True)
 753
 754             git.switch(top)
 755         else:
 756             # new patch needs to be refreshed.
 757             # The current patch is empty after merge.
 758             patch.set_bottom(head, backup = True)
 759             patch.set_top(head, backup = True)
 760
 761             # Try the fast applying first. If this fails, fall back to the
 762             # three-way merge
 763             if not git.apply_diff(bottom, top):
 764                 # if git.apply_diff() fails, the patch requires a diff3
 765                 # merge and can be reported as modified
 766                 modified = True
 767
 768                 # merge can fail but the patch needs to be pushed
 769                 try:
 770                     git.merge(bottom, head, top)
 771                 except git.GitException, ex:
 772                     print >> sys.stderr, \
 773                           'The merge failed during "push". ' \
 774                           'Use "refresh" after fixing the conflicts'
 775
 776         append_string(self.__applied_file, name)
 777
 778         unapplied.remove(name)
 779         f = file(self.__unapplied_file, 'w+')
 780         f.writelines([line + '\n' for line in unapplied])
 781         f.close()
 782
 783         self.__set_current(name)
 784
 785         # head == bottom case doesn't need to refresh the patch
 786         if head != bottom:
 787             if not ex:
 788                 # if the merge was OK and no conflicts, just refresh the patch
 789                 # The GIT cache was already updated by the merge operation
 790                 self.refresh_patch(cache_update = False)
 791             else:
 792                 raise StackException, str(ex)
 793
 794         return modified
 795
 796     def undo_push(self):
 797         name = self.get_current()
 798         assert(name)
 799
 800         patch = Patch(name, self.__patch_dir)
 801         git.reset()
 802         self.pop_patch(name)
 803         return patch.restore_old_boundaries()
 804
 805     def pop_patch(self, name):
 806         """Pops the top patch from the stack
 807         """
 808         applied = self.get_applied()
 809         applied.reverse()
 810         assert(name in applied)
 811
 812         patch = Patch(name, self.__patch_dir)
 813
 814         git.switch(patch.get_bottom())
 815
 816         # save the new applied list
 817         idx = applied.index(name) + 1
 818
 819         popped = applied[:idx]
 820         popped.reverse()
 821         unapplied = popped + self.get_unapplied()
 822
 823         f = file(self.__unapplied_file, 'w+')
 824         f.writelines([line + '\n' for line in unapplied])
 825         f.close()
 826
 827         del applied[:idx]
 828         applied.reverse()
 829
 830         f = file(self.__applied_file, 'w+')
 831         f.writelines([line + '\n' for line in applied])
 832         f.close()
 833
 834         if applied == []:
 835             self.__set_current(None)
 836         else:
 837             self.__set_current(applied[-1])
 838
 839         self.__end_stack_check()
 840
 841     def empty_patch(self, name):
 842         """Returns True if the patch is empty
 843         """
 844         patch = Patch(name, self.__patch_dir)
 845         bottom = patch.get_bottom()
 846         top = patch.get_top()
 847
 848         if bottom == top:
 849             return True
 850         elif git.get_commit(top).get_tree() \
 851                  == git.get_commit(bottom).get_tree():
 852             return True
 853
 854         return False
 855
 856     def rename_patch(self, oldname, newname):
 857         applied = self.get_applied()
 858         unapplied = self.get_unapplied()
 859
 860         if oldname == newname:
 861             raise StackException, '"To" name and "from" name are the same'
 862
 863         if newname in applied or newname in unapplied:
 864             raise StackException, 'Patch "%s" already exists' % newname
 865
 866         if oldname in unapplied:
 867             Patch(oldname, self.__patch_dir).rename(newname)
 868             unapplied[unapplied.index(oldname)] = newname
 869
 870             f = file(self.__unapplied_file, 'w+')
 871             f.writelines([line + '\n' for line in unapplied])
 872             f.close()
 873         elif oldname in applied:
 874             Patch(oldname, self.__patch_dir).rename(newname)
 875             if oldname == self.get_current():
 876                 self.__set_current(newname)
 877
 878             applied[applied.index(oldname)] = newname
 879
 880             f = file(self.__applied_file, 'w+')
 881             f.writelines([line + '\n' for line in applied])
 882             f.close()
 883         else:
 884             raise StackException, 'Unknown patch "%s"' % oldname