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.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         if name:
 261             self.__name = name
 262         else:
 263             self.__name = git.get_head_file()
 264
 265         if self.__name:
 266             self.__patch_dir = os.path.join(git.base_dir, 'patches',
 267                                             self.__name)
 268             self.__base_file = os.path.join(git.base_dir, 'refs', 'bases',
 269                                             self.__name)
 270             self.__applied_file = os.path.join(self.__patch_dir, 'applied')
 271             self.__unapplied_file = os.path.join(self.__patch_dir, 'unapplied')
 272             self.__current_file = os.path.join(self.__patch_dir, 'current')
 273             self.__descr_file = os.path.join(self.__patch_dir, 'description')
 274
 275     def get_branch(self):
 276         """Return the branch name for the Series object
 277         """
 278         return self.__name
 279
 280     def __set_current(self, name):
 281         """Sets the topmost patch
 282         """
 283         if name:
 284             write_string(self.__current_file, name)
 285         else:
 286             create_empty_file(self.__current_file)
 287
 288     def get_patch(self, name):
 289         """Return a Patch object for the given name
 290         """
 291         return Patch(name, self.__patch_dir)
 292
 293     def get_current(self):
 294         """Return a Patch object representing the topmost patch
 295         """
 296         if os.path.isfile(self.__current_file):
 297             name = read_string(self.__current_file)
 298         else:
 299             return None
 300         if name == '':
 301             return None
 302         else:
 303             return name
 304
 305     def get_applied(self):
 306         if not os.path.isfile(self.__applied_file):
 307             raise StackException, 'Branch "%s" not initialised' % self.__name
 308         f = file(self.__applied_file)
 309         names = [line.strip() for line in f.readlines()]
 310         f.close()
 311         return names
 312
 313     def get_unapplied(self):
 314         if not os.path.isfile(self.__unapplied_file):
 315             raise StackException, 'Branch "%s" not initialised' % self.__name
 316         f = file(self.__unapplied_file)
 317         names = [line.strip() for line in f.readlines()]
 318         f.close()
 319         return names
 320
 321     def get_base_file(self):
 322         return self.__base_file
 323
 324     def get_protected(self):
 325         return os.path.isfile(os.path.join(self.__patch_dir, 'protected'))
 326
 327     def protect(self):
 328         protect_file = os.path.join(self.__patch_dir, 'protected')
 329         if not os.path.isfile(protect_file):
 330             create_empty_file(protect_file)
 331
 332     def unprotect(self):
 333         protect_file = os.path.join(self.__patch_dir, 'protected')
 334         if os.path.isfile(protect_file):
 335             os.remove(protect_file)
 336
 337     def get_description(self):
 338         if os.path.isfile(self.__descr_file):
 339             return read_string(self.__descr_file)
 340         else:
 341             return ''
 342
 343     def __patch_is_current(self, patch):
 344         return patch.get_name() == read_string(self.__current_file)
 345
 346     def __patch_applied(self, name):
 347         """Return true if the patch exists in the applied list
 348         """
 349         return name in self.get_applied()
 350
 351     def __patch_unapplied(self, name):
 352         """Return true if the patch exists in the unapplied list
 353         """
 354         return name in self.get_unapplied()
 355
 356     def __begin_stack_check(self):
 357         """Save the current HEAD into .git/refs/heads/base if the stack
 358         is empty
 359         """
 360         if len(self.get_applied()) == 0:
 361             head = git.get_head()
 362             write_string(self.__base_file, head)
 363
 364     def __end_stack_check(self):
 365         """Remove .git/refs/heads/base if the stack is empty.
 366         This warning should never happen
 367         """
 368         if len(self.get_applied()) == 0 \
 369            and read_string(self.__base_file) != git.get_head():
 370             print 'Warning: stack empty but the HEAD and base are different'
 371
 372     def head_top_equal(self):
 373         """Return true if the head and the top are the same
 374         """
 375         crt = self.get_current()
 376         if not crt:
 377             # we don't care, no patches applied
 378             return True
 379         return git.get_head() == Patch(crt, self.__patch_dir).get_top()
 380
 381     def is_initialised(self):
 382         """Checks if series is already initialised
 383         """
 384         return os.path.isdir(self.__patch_dir)
 385
 386     def init(self):
 387         """Initialises the stgit series
 388         """
 389         bases_dir = os.path.join(git.base_dir, 'refs', 'bases')
 390
 391         if self.is_initialised():
 392             raise StackException, self.__patch_dir + ' already exists'
 393         os.makedirs(self.__patch_dir)
 394
 395         if not os.path.isdir(bases_dir):
 396             os.makedirs(bases_dir)
 397
 398         create_empty_file(self.__applied_file)
 399         create_empty_file(self.__unapplied_file)
 400         create_empty_file(self.__descr_file)
 401         self.__begin_stack_check()
 402
 403     def delete(self, force = False):
 404         """Deletes an stgit series
 405         """
 406         if self.is_initialised():
 407             patches = self.get_unapplied() + self.get_applied()
 408             if not force and patches:
 409                 raise StackException, \
 410                       'Cannot delete: the series still contains patches'
 411             patches.reverse()
 412             for p in patches:
 413                 self.delete_patch(p)
 414
 415             if os.path.isfile(self.__applied_file):
 416                 os.remove(self.__applied_file)
 417             if os.path.isfile(self.__unapplied_file):
 418                 os.remove(self.__unapplied_file)
 419             if os.path.isfile(self.__current_file):
 420                 os.remove(self.__current_file)
 421             if os.path.isfile(self.__descr_file):
 422                 os.remove(self.__descr_file)
 423             if not os.listdir(self.__patch_dir):
 424                 os.rmdir(self.__patch_dir)
 425             else:
 426                 print 'Series directory %s is not empty.' % self.__name
 427
 428         if os.path.isfile(self.__base_file):
 429             os.remove(self.__base_file)
 430
 431     def refresh_patch(self, message = None, edit = False, show_patch = False,
 432                       cache_update = True,
 433                       author_name = None, author_email = None,
 434                       author_date = None,
 435                       committer_name = None, committer_email = None):
 436         """Generates a new commit for the given patch
 437         """
 438         name = self.get_current()
 439         if not name:
 440             raise StackException, 'No patches applied'
 441
 442         patch = Patch(name, self.__patch_dir)
 443
 444         descr = patch.get_description()
 445         if not (message or descr):
 446             edit = True
 447             descr = ''
 448         elif message:
 449             descr = message
 450
 451         if not message and edit:
 452             descr = edit_file(self, descr.rstrip(), \
 453                               'Please edit the description for patch "%s" ' \
 454                               'above.' % name, show_patch)
 455
 456         if not author_name:
 457             author_name = patch.get_authname()
 458         if not author_email:
 459             author_email = patch.get_authemail()
 460         if not author_date:
 461             author_date = patch.get_authdate()
 462         if not committer_name:
 463             committer_name = patch.get_commname()
 464         if not committer_email:
 465             committer_email = patch.get_commemail()
 466
 467         commit_id = git.commit(message = descr, parents = [patch.get_bottom()],
 468                                cache_update = cache_update,
 469                                allowempty = True,
 470                                author_name = author_name,
 471                                author_email = author_email,
 472                                author_date = author_date,
 473                                committer_name = committer_name,
 474                                committer_email = committer_email)
 475
 476         patch.set_top(commit_id)
 477         patch.set_description(descr)
 478         patch.set_authname(author_name)
 479         patch.set_authemail(author_email)
 480         patch.set_authdate(author_date)
 481         patch.set_commname(committer_name)
 482         patch.set_commemail(committer_email)
 483
 484         return commit_id
 485
 486     def new_patch(self, name, message = None, can_edit = True,
 487                   unapplied = False, show_patch = False,
 488                   top = None, bottom = None,
 489                   author_name = None, author_email = None, author_date = None,
 490                   committer_name = None, committer_email = None):
 491         """Creates a new patch
 492         """
 493         if self.__patch_applied(name) or self.__patch_unapplied(name):
 494             raise StackException, 'Patch "%s" already exists' % name
 495
 496         if not message and can_edit:
 497             descr = edit_file(self, None, \
 498                               'Please enter the description for patch "%s" ' \
 499                               'above.' % name, show_patch)
 500         else:
 501             descr = message
 502
 503         head = git.get_head()
 504
 505         self.__begin_stack_check()
 506
 507         patch = Patch(name, self.__patch_dir)
 508         patch.create()
 509
 510         if bottom:
 511             patch.set_bottom(bottom)
 512         else:
 513             patch.set_bottom(head)
 514         if top:
 515             patch.set_top(top)
 516         else:
 517             patch.set_top(head)
 518
 519         patch.set_description(descr)
 520         patch.set_authname(author_name)
 521         patch.set_authemail(author_email)
 522         patch.set_authdate(author_date)
 523         patch.set_commname(committer_name)
 524         patch.set_commemail(committer_email)
 525
 526         if unapplied:
 527             patches = [patch.get_name()] + self.get_unapplied()
 528
 529             f = file(self.__unapplied_file, 'w+')
 530             f.writelines([line + '\n' for line in patches])
 531             f.close()
 532         else:
 533             append_string(self.__applied_file, patch.get_name())
 534             self.__set_current(name)
 535
 536     def delete_patch(self, name):
 537         """Deletes a patch
 538         """
 539         patch = Patch(name, self.__patch_dir)
 540
 541         if self.__patch_is_current(patch):
 542             self.pop_patch(name)
 543         elif self.__patch_applied(name):
 544             raise StackException, 'Cannot remove an applied patch, "%s", ' \
 545                   'which is not current' % name
 546         elif not name in self.get_unapplied():
 547             raise StackException, 'Unknown patch "%s"' % name
 548
 549         patch.delete()
 550
 551         unapplied = self.get_unapplied()
 552         unapplied.remove(name)
 553         f = file(self.__unapplied_file, 'w+')
 554         f.writelines([line + '\n' for line in unapplied])
 555         f.close()
 556
 557     def forward_patches(self, names):
 558         """Try to fast-forward an array of patches.
 559
 560         On return, patches in names[0:returned_value] have been pushed on the
 561         stack. Apply the rest with push_patch
 562         """
 563         unapplied = self.get_unapplied()
 564         self.__begin_stack_check()
 565
 566         forwarded = 0
 567         top = git.get_head()
 568
 569         for name in names:
 570             assert(name in unapplied)
 571
 572             patch = Patch(name, self.__patch_dir)
 573
 574             head = top
 575             bottom = patch.get_bottom()
 576             top = patch.get_top()
 577
 578             # top != bottom always since we have a commit for each patch
 579             if head == bottom:
 580                 # reset the backup information
 581                 patch.set_bottom(head, backup = True)
 582                 patch.set_top(top, backup = True)
 583
 584             else:
 585                 head_tree = git.get_commit(head).get_tree()
 586                 bottom_tree = git.get_commit(bottom).get_tree()
 587                 if head_tree == bottom_tree:
 588                     # We must just reparent this patch and create a new commit
 589                     # for it
 590                     descr = patch.get_description()
 591                     author_name = patch.get_authname()
 592                     author_email = patch.get_authemail()
 593                     author_date = patch.get_authdate()
 594                     committer_name = patch.get_commname()
 595                     committer_email = patch.get_commemail()
 596
 597                     top_tree = git.get_commit(top).get_tree()
 598
 599                     top = git.commit(message = descr, parents = [head],
 600                                      cache_update = False,
 601                                      tree_id = top_tree,
 602                                      allowempty = True,
 603                                      author_name = author_name,
 604                                      author_email = author_email,
 605                                      author_date = author_date,
 606                                      committer_name = committer_name,
 607                                      committer_email = committer_email)
 608
 609                     patch.set_bottom(head, backup = True)
 610                     patch.set_top(top, backup = True)
 611                 else:
 612                     top = head
 613                     # stop the fast-forwarding, must do a real merge
 614                     break
 615
 616             forwarded+=1
 617             unapplied.remove(name)
 618
 619         git.switch(top)
 620
 621         append_strings(self.__applied_file, names[0:forwarded])
 622
 623         f = file(self.__unapplied_file, 'w+')
 624         f.writelines([line + '\n' for line in unapplied])
 625         f.close()
 626
 627         self.__set_current(name)
 628
 629         return forwarded
 630
 631     def push_patch(self, name):
 632         """Pushes a patch on the stack
 633         """
 634         unapplied = self.get_unapplied()
 635         assert(name in unapplied)
 636
 637         self.__begin_stack_check()
 638
 639         patch = Patch(name, self.__patch_dir)
 640
 641         head = git.get_head()
 642         bottom = patch.get_bottom()
 643         top = patch.get_top()
 644
 645         ex = None
 646         modified = False
 647
 648         # top != bottom always since we have a commit for each patch
 649         if head == bottom:
 650             # reset the backup information
 651             patch.set_bottom(bottom, backup = True)
 652             patch.set_top(top, backup = True)
 653
 654             git.switch(top)
 655         else:
 656             # new patch needs to be refreshed.
 657             # The current patch is empty after merge.
 658             patch.set_bottom(head, backup = True)
 659             patch.set_top(head, backup = True)
 660
 661             # Try the fast applying first. If this fails, fall back to the
 662             # three-way merge
 663             if not git.apply_diff(bottom, top):
 664                 # if git.apply_diff() fails, the patch requires a diff3
 665                 # merge and can be reported as modified
 666                 modified = True
 667
 668                 # merge can fail but the patch needs to be pushed
 669                 try:
 670                     git.merge(bottom, head, top)
 671                 except git.GitException, ex:
 672                     print >> sys.stderr, \
 673                           'The merge failed during "push". ' \
 674                           'Use "refresh" after fixing the conflicts'
 675
 676         append_string(self.__applied_file, name)
 677
 678         unapplied.remove(name)
 679         f = file(self.__unapplied_file, 'w+')
 680         f.writelines([line + '\n' for line in unapplied])
 681         f.close()
 682
 683         self.__set_current(name)
 684
 685         # head == bottom case doesn't need to refresh the patch
 686         if head != bottom:
 687             if not ex:
 688                 # if the merge was OK and no conflicts, just refresh the patch
 689                 # The GIT cache was already updated by the merge operation
 690                 self.refresh_patch(cache_update = False)
 691             else:
 692                 raise StackException, str(ex)
 693
 694         return modified
 695
 696     def undo_push(self):
 697         name = self.get_current()
 698         assert(name)
 699
 700         patch = Patch(name, self.__patch_dir)
 701         git.reset()
 702         self.pop_patch(name)
 703         return patch.restore_old_boundaries()
 704
 705     def pop_patch(self, name):
 706         """Pops the top patch from the stack
 707         """
 708         applied = self.get_applied()
 709         applied.reverse()
 710         assert(name in applied)
 711
 712         patch = Patch(name, self.__patch_dir)
 713
 714         git.switch(patch.get_bottom())
 715
 716         # save the new applied list
 717         idx = applied.index(name) + 1
 718
 719         popped = applied[:idx]
 720         popped.reverse()
 721         unapplied = popped + self.get_unapplied()
 722
 723         f = file(self.__unapplied_file, 'w+')
 724         f.writelines([line + '\n' for line in unapplied])
 725         f.close()
 726
 727         del applied[:idx]
 728         applied.reverse()
 729
 730         f = file(self.__applied_file, 'w+')
 731         f.writelines([line + '\n' for line in applied])
 732         f.close()
 733
 734         if applied == []:
 735             self.__set_current(None)
 736         else:
 737             self.__set_current(applied[-1])
 738
 739         self.__end_stack_check()
 740
 741     def empty_patch(self, name):
 742         """Returns True if the patch is empty
 743         """
 744         patch = Patch(name, self.__patch_dir)
 745         bottom = patch.get_bottom()
 746         top = patch.get_top()
 747
 748         if bottom == top:
 749             return True
 750         elif git.get_commit(top).get_tree() \
 751                  == git.get_commit(bottom).get_tree():
 752             return True
 753
 754         return False
 755
 756     def rename_patch(self, oldname, newname):
 757         applied = self.get_applied()
 758         unapplied = self.get_unapplied()
 759
 760         if newname in applied or newname in unapplied:
 761             raise StackException, 'Patch "%s" already exists' % newname
 762
 763         if oldname in unapplied:
 764             Patch(oldname, self.__patch_dir).rename(newname)
 765             unapplied[unapplied.index(oldname)] = newname
 766
 767             f = file(self.__unapplied_file, 'w+')
 768             f.writelines([line + '\n' for line in unapplied])
 769             f.close()
 770         elif oldname in applied:
 771             Patch(oldname, self.__patch_dir).rename(newname)
 772             if oldname == self.get_current():
 773                 self.__set_current(newname)
 774
 775             applied[applied.index(oldname)] = newname
 776
 777             f = file(self.__applied_file, 'w+')
 778             f.writelines([line + '\n' for line in applied])
 779             f.close()
 780         else:
 781             raise StackException, 'Unknown patch "%s"' % oldname