mdw@git.distorted.org.uk Git - 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, patch_dir):
 126         self.__patch_dir = patch_dir
 127         self.__name = name
 128         self.__dir = os.path.join(self.__patch_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.__patch_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.__patch_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         self.__applied_file = os.path.join(self.__patch_dir, 'applied')
 274         self.__unapplied_file = os.path.join(self.__patch_dir, 'unapplied')
 275         self.__current_file = os.path.join(self.__patch_dir, 'current')
 276         self.__descr_file = os.path.join(self.__patch_dir, 'description')
 277
 278     def get_branch(self):
 279         """Return the branch name for the Series object
 280         """
 281         return self.__name
 282
 283     def __set_current(self, name):
 284         """Sets the topmost patch
 285         """
 286         if name:
 287             write_string(self.__current_file, name)
 288         else:
 289             create_empty_file(self.__current_file)
 290
 291     def get_patch(self, name):
 292         """Return a Patch object for the given name
 293         """
 294         return Patch(name, self.__patch_dir)
 295
 296     def get_current(self):
 297         """Return a Patch object representing the topmost patch
 298         """
 299         if os.path.isfile(self.__current_file):
 300             name = read_string(self.__current_file)
 301         else:
 302             return None
 303         if name == '':
 304             return None
 305         else:
 306             return name
 307
 308     def get_applied(self):
 309         if not os.path.isfile(self.__applied_file):
 310             raise StackException, 'Branch "%s" not initialised' % self.__name
 311         f = file(self.__applied_file)
 312         names = [line.strip() for line in f.readlines()]
 313         f.close()
 314         return names
 315
 316     def get_unapplied(self):
 317         if not os.path.isfile(self.__unapplied_file):
 318             raise StackException, 'Branch "%s" not initialised' % self.__name
 319         f = file(self.__unapplied_file)
 320         names = [line.strip() for line in f.readlines()]
 321         f.close()
 322         return names
 323
 324     def get_base_file(self):
 325         return self.__base_file
 326
 327     def get_protected(self):
 328         return os.path.isfile(os.path.join(self.__patch_dir, 'protected'))
 329
 330     def protect(self):
 331         protect_file = os.path.join(self.__patch_dir, 'protected')
 332         if not os.path.isfile(protect_file):
 333             create_empty_file(protect_file)
 334
 335     def unprotect(self):
 336         protect_file = os.path.join(self.__patch_dir, 'protected')
 337         if os.path.isfile(protect_file):
 338             os.remove(protect_file)
 339
 340     def get_description(self):
 341         if os.path.isfile(self.__descr_file):
 342             return read_string(self.__descr_file)
 343         else:
 344             return ''
 345
 346     def __patch_is_current(self, patch):
 347         return patch.get_name() == read_string(self.__current_file)
 348
 349     def __patch_applied(self, name):
 350         """Return true if the patch exists in the applied list
 351         """
 352         return name in self.get_applied()
 353
 354     def __patch_unapplied(self, name):
 355         """Return true if the patch exists in the unapplied list
 356         """
 357         return name in self.get_unapplied()
 358
 359     def __begin_stack_check(self):
 360         """Save the current HEAD into .git/refs/heads/base if the stack
 361         is empty
 362         """
 363         if len(self.get_applied()) == 0:
 364             head = git.get_head()
 365             write_string(self.__base_file, head)
 366
 367     def __end_stack_check(self):
 368         """Remove .git/refs/heads/base if the stack is empty.
 369         This warning should never happen
 370         """
 371         if len(self.get_applied()) == 0 \
 372            and read_string(self.__base_file) != git.get_head():
 373             print 'Warning: stack empty but the HEAD and base are different'
 374
 375     def head_top_equal(self):
 376         """Return true if the head and the top are the same
 377         """
 378         crt = self.get_current()
 379         if not crt:
 380             # we don't care, no patches applied
 381             return True
 382         return git.get_head() == Patch(crt, self.__patch_dir).get_top()
 383
 384     def is_initialised(self):
 385         """Checks if series is already initialised
 386         """
 387         return os.path.isdir(self.__patch_dir)
 388
 389     def init(self):
 390         """Initialises the stgit series
 391         """
 392         bases_dir = os.path.join(git.get_base_dir(), 'refs', 'bases')
 393
 394         if self.is_initialised():
 395             raise StackException, self.__patch_dir + ' already exists'
 396         os.makedirs(self.__patch_dir)
 397
 398         if not os.path.isdir(bases_dir):
 399             os.makedirs(bases_dir)
 400
 401         create_empty_file(self.__applied_file)
 402         create_empty_file(self.__unapplied_file)
 403         create_empty_file(self.__descr_file)
 404         self.__begin_stack_check()
 405
 406     def rename(self, to_name):
 407         """Renames a series
 408         """
 409         to_stack = Series(to_name)
 410
 411         if to_stack.is_initialised():
 412             raise StackException, '"%s" already exists' % to_stack.get_branch()
 413         if os.path.exists(to_stack.__base_file):
 414             os.remove(to_stack.__base_file)
 415
 416         git.rename_branch(self.__name, to_name)
 417
 418         if os.path.isdir(self.__patch_dir):
 419             os.rename(self.__patch_dir, to_stack.__patch_dir)
 420         if os.path.exists(self.__base_file):
 421             os.rename(self.__base_file, to_stack.__base_file)
 422
 423         self.__init__(to_name)
 424
 425     def clone(self, target_series):
 426         """Clones a series
 427         """
 428         base = read_string(self.get_base_file())
 429         git.create_branch(target_series, tree_id = base)
 430         Series(target_series).init()
 431         new_series = Series(target_series)
 432
 433         # generate an artificial description file
 434         write_string(new_series.__descr_file, 'clone of "%s"' % self.__name)
 435
 436         # clone self's entire series as unapplied patches
 437         patches = self.get_applied() + self.get_unapplied()
 438         patches.reverse()
 439         for p in patches:
 440             patch = self.get_patch(p)
 441             new_series.new_patch(p, message = patch.get_description(),
 442                                  can_edit = False, unapplied = True,
 443                                  bottom = patch.get_bottom(),
 444                                  top = patch.get_top(),
 445                                  author_name = patch.get_authname(),
 446                                  author_email = patch.get_authemail(),
 447                                  author_date = patch.get_authdate())
 448
 449         # fast forward the cloned series to self's top
 450         new_series.forward_patches(self.get_applied())
 451
 452     def delete(self, force = False):
 453         """Deletes an stgit series
 454         """
 455         if self.is_initialised():
 456             patches = self.get_unapplied() + self.get_applied()
 457             if not force and patches:
 458                 raise StackException, \
 459                       'Cannot delete: the series still contains patches'
 460             for p in patches:
 461                 Patch(p, self.__patch_dir).delete()
 462
 463             if os.path.exists(self.__applied_file):
 464                 os.remove(self.__applied_file)
 465             if os.path.exists(self.__unapplied_file):
 466                 os.remove(self.__unapplied_file)
 467             if os.path.exists(self.__current_file):
 468                 os.remove(self.__current_file)
 469             if os.path.exists(self.__descr_file):
 470                 os.remove(self.__descr_file)
 471             if not os.listdir(self.__patch_dir):
 472                 os.rmdir(self.__patch_dir)
 473             else:
 474                 print 'Series directory %s is not empty.' % self.__name
 475
 476         if os.path.exists(self.__base_file):
 477             os.remove(self.__base_file)
 478
 479     def refresh_patch(self, files = None, message = None, edit = False,
 480                       show_patch = False,
 481                       cache_update = True,
 482                       author_name = None, author_email = None,
 483                       author_date = None,
 484                       committer_name = None, committer_email = None):
 485         """Generates a new commit for the given patch
 486         """
 487         name = self.get_current()
 488         if not name:
 489             raise StackException, 'No patches applied'
 490
 491         patch = Patch(name, self.__patch_dir)
 492
 493         descr = patch.get_description()
 494         if not (message or descr):
 495             edit = True
 496             descr = ''
 497         elif message:
 498             descr = message
 499
 500         if not message and edit:
 501             descr = edit_file(self, descr.rstrip(), \
 502                               'Please edit the description for patch "%s" ' \
 503                               'above.' % name, show_patch)
 504
 505         if not author_name:
 506             author_name = patch.get_authname()
 507         if not author_email:
 508             author_email = patch.get_authemail()
 509         if not author_date:
 510             author_date = patch.get_authdate()
 511         if not committer_name:
 512             committer_name = patch.get_commname()
 513         if not committer_email:
 514             committer_email = patch.get_commemail()
 515
 516         commit_id = git.commit(files = files,
 517                                message = descr, parents = [patch.get_bottom()],
 518                                cache_update = cache_update,
 519                                allowempty = True,
 520                                author_name = author_name,
 521                                author_email = author_email,
 522                                author_date = author_date,
 523                                committer_name = committer_name,
 524                                committer_email = committer_email)
 525
 526         patch.set_top(commit_id)
 527         patch.set_description(descr)
 528         patch.set_authname(author_name)
 529         patch.set_authemail(author_email)
 530         patch.set_authdate(author_date)
 531         patch.set_commname(committer_name)
 532         patch.set_commemail(committer_email)
 533
 534         return commit_id
 535
 536     def new_patch(self, name, message = None, can_edit = True,
 537                   unapplied = False, show_patch = False,
 538                   top = None, bottom = None,
 539                   author_name = None, author_email = None, author_date = None,
 540                   committer_name = None, committer_email = None):
 541         """Creates a new patch
 542         """
 543         if self.__patch_applied(name) or self.__patch_unapplied(name):
 544             raise StackException, 'Patch "%s" already exists' % name
 545
 546         if not message and can_edit:
 547             descr = edit_file(self, None, \
 548                               'Please enter the description for patch "%s" ' \
 549                               'above.' % name, show_patch)
 550         else:
 551             descr = message
 552
 553         head = git.get_head()
 554
 555         self.__begin_stack_check()
 556
 557         patch = Patch(name, self.__patch_dir)
 558         patch.create()
 559
 560         if bottom:
 561             patch.set_bottom(bottom)
 562         else:
 563             patch.set_bottom(head)
 564         if top:
 565             patch.set_top(top)
 566         else:
 567             patch.set_top(head)
 568
 569         patch.set_description(descr)
 570         patch.set_authname(author_name)
 571         patch.set_authemail(author_email)
 572         patch.set_authdate(author_date)
 573         patch.set_commname(committer_name)
 574         patch.set_commemail(committer_email)
 575
 576         if unapplied:
 577             patches = [patch.get_name()] + self.get_unapplied()
 578
 579             f = file(self.__unapplied_file, 'w+')
 580             f.writelines([line + '\n' for line in patches])
 581             f.close()
 582         else:
 583             append_string(self.__applied_file, patch.get_name())
 584             self.__set_current(name)
 585
 586     def delete_patch(self, name):
 587         """Deletes a patch
 588         """
 589         patch = Patch(name, self.__patch_dir)
 590
 591         if self.__patch_is_current(patch):
 592             self.pop_patch(name)
 593         elif self.__patch_applied(name):
 594             raise StackException, 'Cannot remove an applied patch, "%s", ' \
 595                   'which is not current' % name
 596         elif not name in self.get_unapplied():
 597             raise StackException, 'Unknown patch "%s"' % name
 598
 599         patch.delete()
 600
 601         unapplied = self.get_unapplied()
 602         unapplied.remove(name)
 603         f = file(self.__unapplied_file, 'w+')
 604         f.writelines([line + '\n' for line in unapplied])
 605         f.close()
 606
 607     def forward_patches(self, names):
 608         """Try to fast-forward an array of patches.
 609
 610         On return, patches in names[0:returned_value] have been pushed on the
 611         stack. Apply the rest with push_patch
 612         """
 613         unapplied = self.get_unapplied()
 614         self.__begin_stack_check()
 615
 616         forwarded = 0
 617         top = git.get_head()
 618
 619         for name in names:
 620             assert(name in unapplied)
 621
 622             patch = Patch(name, self.__patch_dir)
 623
 624             head = top
 625             bottom = patch.get_bottom()
 626             top = patch.get_top()
 627
 628             # top != bottom always since we have a commit for each patch
 629             if head == bottom:
 630                 # reset the backup information
 631                 patch.set_bottom(head, backup = True)
 632                 patch.set_top(top, backup = True)
 633
 634             else:
 635                 head_tree = git.get_commit(head).get_tree()
 636                 bottom_tree = git.get_commit(bottom).get_tree()
 637                 if head_tree == bottom_tree:
 638                     # We must just reparent this patch and create a new commit
 639                     # for it
 640                     descr = patch.get_description()
 641                     author_name = patch.get_authname()
 642                     author_email = patch.get_authemail()
 643                     author_date = patch.get_authdate()
 644                     committer_name = patch.get_commname()
 645                     committer_email = patch.get_commemail()
 646
 647                     top_tree = git.get_commit(top).get_tree()
 648
 649                     top = git.commit(message = descr, parents = [head],
 650                                      cache_update = False,
 651                                      tree_id = top_tree,
 652                                      allowempty = True,
 653                                      author_name = author_name,
 654                                      author_email = author_email,
 655                                      author_date = author_date,
 656                                      committer_name = committer_name,
 657                                      committer_email = committer_email)
 658
 659                     patch.set_bottom(head, backup = True)
 660                     patch.set_top(top, backup = True)
 661                 else:
 662                     top = head
 663                     # stop the fast-forwarding, must do a real merge
 664                     break
 665
 666             forwarded+=1
 667             unapplied.remove(name)
 668
 669         if forwarded == 0:
 670             return 0
 671
 672         git.switch(top)
 673
 674         append_strings(self.__applied_file, names[0:forwarded])
 675
 676         f = file(self.__unapplied_file, 'w+')
 677         f.writelines([line + '\n' for line in unapplied])
 678         f.close()
 679
 680         self.__set_current(name)
 681
 682         return forwarded
 683
 684     def push_patch(self, name):
 685         """Pushes a patch on the stack
 686         """
 687         unapplied = self.get_unapplied()
 688         assert(name in unapplied)
 689
 690         self.__begin_stack_check()
 691
 692         patch = Patch(name, self.__patch_dir)
 693
 694         head = git.get_head()
 695         bottom = patch.get_bottom()
 696         top = patch.get_top()
 697
 698         ex = None
 699         modified = False
 700
 701         # top != bottom always since we have a commit for each patch
 702         if head == bottom:
 703             # reset the backup information
 704             patch.set_bottom(bottom, backup = True)
 705             patch.set_top(top, backup = True)
 706
 707             git.switch(top)
 708         else:
 709             # new patch needs to be refreshed.
 710             # The current patch is empty after merge.
 711             patch.set_bottom(head, backup = True)
 712             patch.set_top(head, backup = True)
 713
 714             # Try the fast applying first. If this fails, fall back to the
 715             # three-way merge
 716             if not git.apply_diff(bottom, top):
 717                 # if git.apply_diff() fails, the patch requires a diff3
 718                 # merge and can be reported as modified
 719                 modified = True
 720
 721                 # merge can fail but the patch needs to be pushed
 722                 try:
 723                     git.merge(bottom, head, top)
 724                 except git.GitException, ex:
 725                     print >> sys.stderr, \
 726                           'The merge failed during "push". ' \
 727                           'Use "refresh" after fixing the conflicts'
 728
 729         append_string(self.__applied_file, name)
 730
 731         unapplied.remove(name)
 732         f = file(self.__unapplied_file, 'w+')
 733         f.writelines([line + '\n' for line in unapplied])
 734         f.close()
 735
 736         self.__set_current(name)
 737
 738         # head == bottom case doesn't need to refresh the patch
 739         if head != bottom:
 740             if not ex:
 741                 # if the merge was OK and no conflicts, just refresh the patch
 742                 # The GIT cache was already updated by the merge operation
 743                 self.refresh_patch(cache_update = False)
 744             else:
 745                 raise StackException, str(ex)
 746
 747         return modified
 748
 749     def undo_push(self):
 750         name = self.get_current()
 751         assert(name)
 752
 753         patch = Patch(name, self.__patch_dir)
 754         git.reset()
 755         self.pop_patch(name)
 756         return patch.restore_old_boundaries()
 757
 758     def pop_patch(self, name):
 759         """Pops the top patch from the stack
 760         """
 761         applied = self.get_applied()
 762         applied.reverse()
 763         assert(name in applied)
 764
 765         patch = Patch(name, self.__patch_dir)
 766
 767         git.switch(patch.get_bottom())
 768
 769         # save the new applied list
 770         idx = applied.index(name) + 1
 771
 772         popped = applied[:idx]
 773         popped.reverse()
 774         unapplied = popped + self.get_unapplied()
 775
 776         f = file(self.__unapplied_file, 'w+')
 777         f.writelines([line + '\n' for line in unapplied])
 778         f.close()
 779
 780         del applied[:idx]
 781         applied.reverse()
 782
 783         f = file(self.__applied_file, 'w+')
 784         f.writelines([line + '\n' for line in applied])
 785         f.close()
 786
 787         if applied == []:
 788             self.__set_current(None)
 789         else:
 790             self.__set_current(applied[-1])
 791
 792         self.__end_stack_check()
 793
 794     def empty_patch(self, name):
 795         """Returns True if the patch is empty
 796         """
 797         patch = Patch(name, self.__patch_dir)
 798         bottom = patch.get_bottom()
 799         top = patch.get_top()
 800
 801         if bottom == top:
 802             return True
 803         elif git.get_commit(top).get_tree() \
 804                  == git.get_commit(bottom).get_tree():
 805             return True
 806
 807         return False
 808
 809     def rename_patch(self, oldname, newname):
 810         applied = self.get_applied()
 811         unapplied = self.get_unapplied()
 812
 813         if oldname == newname:
 814             raise StackException, '"To" name and "from" name are the same'
 815
 816         if newname in applied or newname in unapplied:
 817             raise StackException, 'Patch "%s" already exists' % newname
 818
 819         if oldname in unapplied:
 820             Patch(oldname, self.__patch_dir).rename(newname)
 821             unapplied[unapplied.index(oldname)] = newname
 822
 823             f = file(self.__unapplied_file, 'w+')
 824             f.writelines([line + '\n' for line in unapplied])
 825             f.close()
 826         elif oldname in applied:
 827             Patch(oldname, self.__patch_dir).rename(newname)
 828             if oldname == self.get_current():
 829                 self.__set_current(newname)
 830
 831             applied[applied.index(oldname)] = newname
 832
 833             f = file(self.__applied_file, 'w+')
 834             f.writelines([line + '\n' for line in applied])
 835             f.close()
 836         else:
 837             raise StackException, 'Unknown patch "%s"' % oldname