chiark / gitweb /
0113a1ce64405818afb78a0aa63602cb903ce7a8
[stgit] / 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, basedir, templates
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 = '.stgitmsg.txt'
69     tmpl = templates.get_template('patchdescr.tmpl')
70
71     f = file(fname, 'w+')
72     if line:
73         print >> f, line
74     elif tmpl:
75         print >> f, tmpl,
76     else:
77         print >> f
78     print >> f, __comment_prefix, comment
79     print >> f, __comment_prefix, \
80           'Lines prefixed with "%s" will be automatically removed.' \
81           % __comment_prefix
82     print >> f, __comment_prefix, \
83           'Trailing empty lines will be automatically removed.'
84
85     if show_patch:
86        print >> f, __patch_prefix
87        # series.get_patch(series.get_current()).get_top()
88        git.diff([], series.get_patch(series.get_current()).get_bottom(), None, f)
89
90     #Vim modeline must be near the end.
91     print >> f, __comment_prefix, 'vi: set textwidth=75 filetype=diff nobackup:'
92     f.close()
93
94     # the editor
95     if config.has_option('stgit', 'editor'):
96         editor = config.get('stgit', 'editor')
97     elif 'EDITOR' in os.environ:
98         editor = os.environ['EDITOR']
99     else:
100         editor = 'vi'
101     editor += ' %s' % fname
102
103     print 'Invoking the editor: "%s"...' % editor,
104     sys.stdout.flush()
105     print 'done (exit code: %d)' % os.system(editor)
106
107     f = file(fname, 'r+')
108
109     __clean_comments(f)
110     f.seek(0)
111     result = f.read()
112
113     f.close()
114     os.remove(fname)
115
116     return result
117
118 #
119 # Classes
120 #
121
122 class Patch:
123     """Basic patch implementation
124     """
125     def __init__(self, name, series_dir, refs_dir):
126         self.__series_dir = series_dir
127         self.__name = name
128         self.__dir = os.path.join(self.__series_dir, self.__name)
129         self.__refs_dir = refs_dir
130         self.__top_ref_file = os.path.join(self.__refs_dir, self.__name)
131         self.__log_ref_file = os.path.join(self.__refs_dir,
132                                            self.__name + '.log')
133
134     def create(self):
135         os.mkdir(self.__dir)
136         create_empty_file(os.path.join(self.__dir, 'bottom'))
137         create_empty_file(os.path.join(self.__dir, 'top'))
138
139     def delete(self):
140         for f in os.listdir(self.__dir):
141             os.remove(os.path.join(self.__dir, f))
142         os.rmdir(self.__dir)
143         os.remove(self.__top_ref_file)
144         if os.path.exists(self.__log_ref_file):
145             os.remove(self.__log_ref_file)
146
147     def get_name(self):
148         return self.__name
149
150     def rename(self, newname):
151         olddir = self.__dir
152         old_top_ref_file = self.__top_ref_file
153         old_log_ref_file = self.__log_ref_file
154         self.__name = newname
155         self.__dir = os.path.join(self.__series_dir, self.__name)
156         self.__top_ref_file = os.path.join(self.__refs_dir, self.__name)
157         self.__log_ref_file = os.path.join(self.__refs_dir,
158                                            self.__name + '.log')
159
160         os.rename(olddir, self.__dir)
161         os.rename(old_top_ref_file, self.__top_ref_file)
162         if os.path.exists(old_log_ref_file):
163             os.rename(old_log_ref_file, self.__log_ref_file)
164
165     def __update_top_ref(self, ref):
166         write_string(self.__top_ref_file, ref)
167
168     def __update_log_ref(self, ref):
169         write_string(self.__log_ref_file, ref)
170
171     def update_top_ref(self):
172         top = self.get_top()
173         if top:
174             self.__update_top_ref(top)
175
176     def __get_field(self, name, multiline = False):
177         id_file = os.path.join(self.__dir, name)
178         if os.path.isfile(id_file):
179             line = read_string(id_file, multiline)
180             if line == '':
181                 return None
182             else:
183                 return line
184         else:
185             return None
186
187     def __set_field(self, name, value, multiline = False):
188         fname = os.path.join(self.__dir, name)
189         if value and value != '':
190             write_string(fname, value, multiline)
191         elif os.path.isfile(fname):
192             os.remove(fname)
193
194     def get_old_bottom(self):
195         return self.__get_field('bottom.old')
196
197     def get_bottom(self):
198         return self.__get_field('bottom')
199
200     def set_bottom(self, value, backup = False):
201         if backup:
202             curr = self.__get_field('bottom')
203             self.__set_field('bottom.old', curr)
204         self.__set_field('bottom', value)
205
206     def get_old_top(self):
207         return self.__get_field('top.old')
208
209     def get_top(self):
210         return self.__get_field('top')
211
212     def set_top(self, value, backup = False):
213         if backup:
214             curr = self.__get_field('top')
215             self.__set_field('top.old', curr)
216         self.__set_field('top', value)
217         self.__update_top_ref(value)
218
219     def restore_old_boundaries(self):
220         bottom = self.__get_field('bottom.old')
221         top = self.__get_field('top.old')
222
223         if top and bottom:
224             self.__set_field('bottom', bottom)
225             self.__set_field('top', top)
226             self.__update_top_ref(top)
227             return True
228         else:
229             return False
230
231     def get_description(self):
232         return self.__get_field('description', True)
233
234     def set_description(self, line):
235         self.__set_field('description', line, True)
236
237     def get_authname(self):
238         return self.__get_field('authname')
239
240     def set_authname(self, name):
241         if not name:
242             if config.has_option('stgit', 'authname'):
243                 name = config.get('stgit', 'authname')
244             elif 'GIT_AUTHOR_NAME' in os.environ:
245                 name = os.environ['GIT_AUTHOR_NAME']
246         self.__set_field('authname', name)
247
248     def get_authemail(self):
249         return self.__get_field('authemail')
250
251     def set_authemail(self, address):
252         if not address:
253             if config.has_option('stgit', 'authemail'):
254                 address = config.get('stgit', 'authemail')
255             elif 'GIT_AUTHOR_EMAIL' in os.environ:
256                 address = os.environ['GIT_AUTHOR_EMAIL']
257         self.__set_field('authemail', address)
258
259     def get_authdate(self):
260         return self.__get_field('authdate')
261
262     def set_authdate(self, date):
263         if not date and 'GIT_AUTHOR_DATE' in os.environ:
264             date = os.environ['GIT_AUTHOR_DATE']
265         self.__set_field('authdate', date)
266
267     def get_commname(self):
268         return self.__get_field('commname')
269
270     def set_commname(self, name):
271         if not name:
272             if config.has_option('stgit', 'commname'):
273                 name = config.get('stgit', 'commname')
274             elif 'GIT_COMMITTER_NAME' in os.environ:
275                 name = os.environ['GIT_COMMITTER_NAME']
276         self.__set_field('commname', name)
277
278     def get_commemail(self):
279         return self.__get_field('commemail')
280
281     def set_commemail(self, address):
282         if not address:
283             if config.has_option('stgit', 'commemail'):
284                 address = config.get('stgit', 'commemail')
285             elif 'GIT_COMMITTER_EMAIL' in os.environ:
286                 address = os.environ['GIT_COMMITTER_EMAIL']
287         self.__set_field('commemail', address)
288
289     def get_log(self):
290         return self.__get_field('log')
291
292     def set_log(self, value, backup = False):
293         self.__set_field('log', value)
294         self.__update_log_ref(value)
295
296
297 class Series:
298     """Class including the operations on series
299     """
300     def __init__(self, name = None):
301         """Takes a series name as the parameter.
302         """
303         try:
304             if name:
305                 self.__name = name
306             else:
307                 self.__name = git.get_head_file()
308             self.__base_dir = basedir.get()
309         except git.GitException, ex:
310             raise StackException, 'GIT tree not initialised: %s' % ex
311
312         self.__series_dir = os.path.join(self.__base_dir, 'patches',
313                                          self.__name)
314         self.__refs_dir = os.path.join(self.__base_dir, 'refs', 'patches',
315                                        self.__name)
316         self.__base_file = os.path.join(self.__base_dir, 'refs', 'bases',
317                                         self.__name)
318
319         self.__applied_file = os.path.join(self.__series_dir, 'applied')
320         self.__unapplied_file = os.path.join(self.__series_dir, 'unapplied')
321         self.__current_file = os.path.join(self.__series_dir, 'current')
322         self.__descr_file = os.path.join(self.__series_dir, 'description')
323
324         # where this series keeps its patches
325         self.__patch_dir = os.path.join(self.__series_dir, 'patches')
326         if not os.path.isdir(self.__patch_dir):
327             self.__patch_dir = self.__series_dir
328
329         # if no __refs_dir, create and populate it (upgrade old repositories)
330         if self.is_initialised() and not os.path.isdir(self.__refs_dir):
331             os.makedirs(self.__refs_dir)
332             for patch in self.get_applied() + self.get_unapplied():
333                 self.get_patch(patch).update_top_ref()
334
335     def get_branch(self):
336         """Return the branch name for the Series object
337         """
338         return self.__name
339
340     def __set_current(self, name):
341         """Sets the topmost patch
342         """
343         if name:
344             write_string(self.__current_file, name)
345         else:
346             create_empty_file(self.__current_file)
347
348     def get_patch(self, name):
349         """Return a Patch object for the given name
350         """
351         return Patch(name, self.__patch_dir, self.__refs_dir)
352
353     def get_current(self):
354         """Return a Patch object representing the topmost patch
355         """
356         if os.path.isfile(self.__current_file):
357             name = read_string(self.__current_file)
358         else:
359             return None
360         if name == '':
361             return None
362         else:
363             return name
364
365     def get_applied(self):
366         if not os.path.isfile(self.__applied_file):
367             raise StackException, 'Branch "%s" not initialised' % self.__name
368         f = file(self.__applied_file)
369         names = [line.strip() for line in f.readlines()]
370         f.close()
371         return names
372
373     def get_unapplied(self):
374         if not os.path.isfile(self.__unapplied_file):
375             raise StackException, 'Branch "%s" not initialised' % self.__name
376         f = file(self.__unapplied_file)
377         names = [line.strip() for line in f.readlines()]
378         f.close()
379         return names
380
381     def get_base_file(self):
382         self.__begin_stack_check()
383         return self.__base_file
384
385     def get_protected(self):
386         return os.path.isfile(os.path.join(self.__series_dir, 'protected'))
387
388     def protect(self):
389         protect_file = os.path.join(self.__series_dir, 'protected')
390         if not os.path.isfile(protect_file):
391             create_empty_file(protect_file)
392
393     def unprotect(self):
394         protect_file = os.path.join(self.__series_dir, 'protected')
395         if os.path.isfile(protect_file):
396             os.remove(protect_file)
397
398     def get_description(self):
399         if os.path.isfile(self.__descr_file):
400             return read_string(self.__descr_file)
401         else:
402             return ''
403
404     def __patch_is_current(self, patch):
405         return patch.get_name() == read_string(self.__current_file)
406
407     def __patch_applied(self, name):
408         """Return true if the patch exists in the applied list
409         """
410         return name in self.get_applied()
411
412     def __patch_unapplied(self, name):
413         """Return true if the patch exists in the unapplied list
414         """
415         return name in self.get_unapplied()
416
417     def __begin_stack_check(self):
418         """Save the current HEAD into .git/refs/heads/base if the stack
419         is empty
420         """
421         if len(self.get_applied()) == 0:
422             head = git.get_head()
423             write_string(self.__base_file, head)
424
425     def __end_stack_check(self):
426         """Remove .git/refs/heads/base if the stack is empty.
427         This warning should never happen
428         """
429         if len(self.get_applied()) == 0 \
430            and read_string(self.__base_file) != git.get_head():
431             print 'Warning: stack empty but the HEAD and base are different'
432
433     def head_top_equal(self):
434         """Return true if the head and the top are the same
435         """
436         crt = self.get_current()
437         if not crt:
438             # we don't care, no patches applied
439             return True
440         return git.get_head() == Patch(crt, self.__patch_dir,
441                                        self.__refs_dir).get_top()
442
443     def is_initialised(self):
444         """Checks if series is already initialised
445         """
446         return os.path.isdir(self.__patch_dir)
447
448     def init(self, create_at=False):
449         """Initialises the stgit series
450         """
451         bases_dir = os.path.join(self.__base_dir, 'refs', 'bases')
452
453         if os.path.exists(self.__patch_dir):
454             raise StackException, self.__patch_dir + ' already exists'
455         if os.path.exists(self.__refs_dir):
456             raise StackException, self.__refs_dir + ' already exists'
457         if os.path.exists(self.__base_file):
458             raise StackException, self.__base_file + ' already exists'
459
460         if (create_at!=False):
461             git.create_branch(self.__name, create_at)
462
463         os.makedirs(self.__patch_dir)
464
465         create_dirs(bases_dir)
466
467         create_empty_file(self.__applied_file)
468         create_empty_file(self.__unapplied_file)
469         create_empty_file(self.__descr_file)
470         os.makedirs(os.path.join(self.__series_dir, 'patches'))
471         os.makedirs(self.__refs_dir)
472         self.__begin_stack_check()
473
474     def convert(self):
475         """Either convert to use a separate patch directory, or
476         unconvert to place the patches in the same directory with
477         series control files
478         """
479         if self.__patch_dir == self.__series_dir:
480             print 'Converting old-style to new-style...',
481             sys.stdout.flush()
482
483             self.__patch_dir = os.path.join(self.__series_dir, 'patches')
484             os.makedirs(self.__patch_dir)
485
486             for p in self.get_applied() + self.get_unapplied():
487                 src = os.path.join(self.__series_dir, p)
488                 dest = os.path.join(self.__patch_dir, p)
489                 os.rename(src, dest)
490
491             print 'done'
492
493         else:
494             print 'Converting new-style to old-style...',
495             sys.stdout.flush()
496
497             for p in self.get_applied() + self.get_unapplied():
498                 src = os.path.join(self.__patch_dir, p)
499                 dest = os.path.join(self.__series_dir, p)
500                 os.rename(src, dest)
501
502             if not os.listdir(self.__patch_dir):
503                 os.rmdir(self.__patch_dir)
504                 print 'done'
505             else:
506                 print 'Patch directory %s is not empty.' % self.__name
507
508             self.__patch_dir = self.__series_dir
509
510     def rename(self, to_name):
511         """Renames a series
512         """
513         to_stack = Series(to_name)
514
515         if to_stack.is_initialised():
516             raise StackException, '"%s" already exists' % to_stack.get_branch()
517         if os.path.exists(to_stack.__base_file):
518             os.remove(to_stack.__base_file)
519
520         git.rename_branch(self.__name, to_name)
521
522         if os.path.isdir(self.__series_dir):
523             rename(os.path.join(self.__base_dir, 'patches'),
524                    self.__name, to_stack.__name)
525         if os.path.exists(self.__base_file):
526             rename(os.path.join(self.__base_dir, 'refs', 'bases'),
527                    self.__name, to_stack.__name)
528         if os.path.exists(self.__refs_dir):
529             rename(os.path.join(self.__base_dir, 'refs', 'patches'),
530                    self.__name, to_stack.__name)
531
532         self.__init__(to_name)
533
534     def clone(self, target_series):
535         """Clones a series
536         """
537         base = read_string(self.get_base_file())
538         Series(target_series).init(create_at = base)
539         new_series = Series(target_series)
540
541         # generate an artificial description file
542         write_string(new_series.__descr_file, 'clone of "%s"' % self.__name)
543
544         # clone self's entire series as unapplied patches
545         patches = self.get_applied() + self.get_unapplied()
546         patches.reverse()
547         for p in patches:
548             patch = self.get_patch(p)
549             new_series.new_patch(p, message = patch.get_description(),
550                                  can_edit = False, unapplied = True,
551                                  bottom = patch.get_bottom(),
552                                  top = patch.get_top(),
553                                  author_name = patch.get_authname(),
554                                  author_email = patch.get_authemail(),
555                                  author_date = patch.get_authdate())
556
557         # fast forward the cloned series to self's top
558         new_series.forward_patches(self.get_applied())
559
560     def delete(self, force = False):
561         """Deletes an stgit series
562         """
563         if self.is_initialised():
564             patches = self.get_unapplied() + self.get_applied()
565             if not force and patches:
566                 raise StackException, \
567                       'Cannot delete: the series still contains patches'
568             for p in patches:
569                 Patch(p, self.__patch_dir, self.__refs_dir).delete()
570
571             if os.path.exists(self.__applied_file):
572                 os.remove(self.__applied_file)
573             if os.path.exists(self.__unapplied_file):
574                 os.remove(self.__unapplied_file)
575             if os.path.exists(self.__current_file):
576                 os.remove(self.__current_file)
577             if os.path.exists(self.__descr_file):
578                 os.remove(self.__descr_file)
579             if not os.listdir(self.__patch_dir):
580                 os.rmdir(self.__patch_dir)
581             else:
582                 print 'Patch directory %s is not empty.' % self.__name
583             if not os.listdir(self.__series_dir):
584                 remove_dirs(os.path.join(self.__base_dir, 'patches'),
585                             self.__name)
586             else:
587                 print 'Series directory %s is not empty.' % self.__name
588             if not os.listdir(self.__refs_dir):
589                 remove_dirs(os.path.join(self.__base_dir, 'refs', 'patches'),
590                             self.__name)
591             else:
592                 print 'Refs directory %s is not empty.' % self.__refs_dir
593
594         if os.path.exists(self.__base_file):
595             remove_file_and_dirs(
596                 os.path.join(self.__base_dir, 'refs', 'bases'), self.__name)
597
598     def refresh_patch(self, files = None, message = None, edit = False,
599                       show_patch = False,
600                       cache_update = True,
601                       author_name = None, author_email = None,
602                       author_date = None,
603                       committer_name = None, committer_email = None,
604                       backup = False, log = 'refresh'):
605         """Generates a new commit for the given patch
606         """
607         name = self.get_current()
608         if not name:
609             raise StackException, 'No patches applied'
610
611         patch = Patch(name, self.__patch_dir, self.__refs_dir)
612
613         descr = patch.get_description()
614         if not (message or descr):
615             edit = True
616             descr = ''
617         elif message:
618             descr = message
619
620         if not message and edit:
621             descr = edit_file(self, descr.rstrip(), \
622                               'Please edit the description for patch "%s" ' \
623                               'above.' % name, show_patch)
624
625         if not author_name:
626             author_name = patch.get_authname()
627         if not author_email:
628             author_email = patch.get_authemail()
629         if not author_date:
630             author_date = patch.get_authdate()
631         if not committer_name:
632             committer_name = patch.get_commname()
633         if not committer_email:
634             committer_email = patch.get_commemail()
635
636         bottom = patch.get_bottom()
637
638         commit_id = git.commit(files = files,
639                                message = descr, parents = [bottom],
640                                cache_update = cache_update,
641                                allowempty = True,
642                                author_name = author_name,
643                                author_email = author_email,
644                                author_date = author_date,
645                                committer_name = committer_name,
646                                committer_email = committer_email)
647
648         patch.set_bottom(bottom, backup = backup)
649         patch.set_top(commit_id, backup = backup)
650         patch.set_description(descr)
651         patch.set_authname(author_name)
652         patch.set_authemail(author_email)
653         patch.set_authdate(author_date)
654         patch.set_commname(committer_name)
655         patch.set_commemail(committer_email)
656
657         if log:
658             self.log_patch(patch, log)
659
660         return commit_id
661
662     def undo_refresh(self):
663         """Undo the patch boundaries changes caused by 'refresh'
664         """
665         name = self.get_current()
666         assert(name)
667
668         patch = Patch(name, self.__patch_dir, self.__refs_dir)
669         old_bottom = patch.get_old_bottom()
670         old_top = patch.get_old_top()
671
672         # the bottom of the patch is not changed by refresh. If the
673         # old_bottom is different, there wasn't any previous 'refresh'
674         # command (probably only a 'push')
675         if old_bottom != patch.get_bottom() or old_top == patch.get_top():
676             raise StackException, 'No refresh undo information available'
677
678         git.reset(tree_id = old_top, check_out = False)
679         if patch.restore_old_boundaries():
680             self.log_patch(patch, 'undo')
681
682     def new_patch(self, name, message = None, can_edit = True,
683                   unapplied = False, show_patch = False,
684                   top = None, bottom = None,
685                   author_name = None, author_email = None, author_date = None,
686                   committer_name = None, committer_email = None,
687                   before_existing = False):
688         """Creates a new patch
689         """
690         if self.__patch_applied(name) or self.__patch_unapplied(name):
691             raise StackException, 'Patch "%s" already exists' % name
692
693         if not message and can_edit:
694             descr = edit_file(self, None, \
695                               'Please enter the description for patch "%s" ' \
696                               'above.' % name, show_patch)
697         else:
698             descr = message
699
700         head = git.get_head()
701
702         self.__begin_stack_check()
703
704         patch = Patch(name, self.__patch_dir, self.__refs_dir)
705         patch.create()
706
707         if bottom:
708             patch.set_bottom(bottom)
709         else:
710             patch.set_bottom(head)
711         if top:
712             patch.set_top(top)
713         else:
714             patch.set_top(head)
715
716         patch.set_description(descr)
717         patch.set_authname(author_name)
718         patch.set_authemail(author_email)
719         patch.set_authdate(author_date)
720         patch.set_commname(committer_name)
721         patch.set_commemail(committer_email)
722
723         if unapplied:
724             self.log_patch(patch, 'new')
725
726             patches = [patch.get_name()] + self.get_unapplied()
727
728             f = file(self.__unapplied_file, 'w+')
729             f.writelines([line + '\n' for line in patches])
730             f.close()
731         elif before_existing:
732             self.log_patch(patch, 'new')
733
734             insert_string(self.__applied_file, patch.get_name())
735             if not self.get_current():
736                 self.__set_current(name)
737         else:
738             append_string(self.__applied_file, patch.get_name())
739             self.__set_current(name)
740
741             self.refresh_patch(cache_update = False, log = 'new')
742
743     def delete_patch(self, name):
744         """Deletes a patch
745         """
746         patch = Patch(name, self.__patch_dir, self.__refs_dir)
747
748         if self.__patch_is_current(patch):
749             self.pop_patch(name)
750         elif self.__patch_applied(name):
751             raise StackException, 'Cannot remove an applied patch, "%s", ' \
752                   'which is not current' % name
753         elif not name in self.get_unapplied():
754             raise StackException, 'Unknown patch "%s"' % name
755
756         patch.delete()
757
758         unapplied = self.get_unapplied()
759         unapplied.remove(name)
760         f = file(self.__unapplied_file, 'w+')
761         f.writelines([line + '\n' for line in unapplied])
762         f.close()
763         self.__begin_stack_check()
764
765     def forward_patches(self, names):
766         """Try to fast-forward an array of patches.
767
768         On return, patches in names[0:returned_value] have been pushed on the
769         stack. Apply the rest with push_patch
770         """
771         unapplied = self.get_unapplied()
772         self.__begin_stack_check()
773
774         forwarded = 0
775         top = git.get_head()
776
777         for name in names:
778             assert(name in unapplied)
779
780             patch = Patch(name, self.__patch_dir, self.__refs_dir)
781
782             head = top
783             bottom = patch.get_bottom()
784             top = patch.get_top()
785
786             # top != bottom always since we have a commit for each patch
787             if head == bottom:
788                 # reset the backup information. No logging since the
789                 # patch hasn't changed
790                 patch.set_bottom(head, backup = True)
791                 patch.set_top(top, backup = True)
792
793             else:
794                 head_tree = git.get_commit(head).get_tree()
795                 bottom_tree = git.get_commit(bottom).get_tree()
796                 if head_tree == bottom_tree:
797                     # We must just reparent this patch and create a new commit
798                     # for it
799                     descr = patch.get_description()
800                     author_name = patch.get_authname()
801                     author_email = patch.get_authemail()
802                     author_date = patch.get_authdate()
803                     committer_name = patch.get_commname()
804                     committer_email = patch.get_commemail()
805
806                     top_tree = git.get_commit(top).get_tree()
807
808                     top = git.commit(message = descr, parents = [head],
809                                      cache_update = False,
810                                      tree_id = top_tree,
811                                      allowempty = True,
812                                      author_name = author_name,
813                                      author_email = author_email,
814                                      author_date = author_date,
815                                      committer_name = committer_name,
816                                      committer_email = committer_email)
817
818                     patch.set_bottom(head, backup = True)
819                     patch.set_top(top, backup = True)
820
821                     self.log_patch(patch, 'push(f)')
822                 else:
823                     top = head
824                     # stop the fast-forwarding, must do a real merge
825                     break
826
827             forwarded+=1
828             unapplied.remove(name)
829
830         if forwarded == 0:
831             return 0
832
833         git.switch(top)
834
835         append_strings(self.__applied_file, names[0:forwarded])
836
837         f = file(self.__unapplied_file, 'w+')
838         f.writelines([line + '\n' for line in unapplied])
839         f.close()
840
841         self.__set_current(name)
842
843         return forwarded
844
845     def merged_patches(self, names):
846         """Test which patches were merged upstream by reverse-applying
847         them in reverse order. The function returns the list of
848         patches detected to have been applied. The state of the tree
849         is restored to the original one
850         """
851         patches = [Patch(name, self.__patch_dir, self.__refs_dir)
852                    for name in names]
853         patches.reverse()
854
855         merged = []
856         for p in patches:
857             if git.apply_diff(p.get_top(), p.get_bottom()):
858                 merged.append(p.get_name())
859         merged.reverse()
860
861         git.reset()
862
863         return merged
864
865     def push_patch(self, name, empty = False):
866         """Pushes a patch on the stack
867         """
868         unapplied = self.get_unapplied()
869         assert(name in unapplied)
870
871         self.__begin_stack_check()
872
873         patch = Patch(name, self.__patch_dir, self.__refs_dir)
874
875         head = git.get_head()
876         bottom = patch.get_bottom()
877         top = patch.get_top()
878
879         ex = None
880         modified = False
881
882         # top != bottom always since we have a commit for each patch
883         if empty:
884             # just make an empty patch (top = bottom = HEAD). This
885             # option is useful to allow undoing already merged
886             # patches. The top is updated by refresh_patch since we
887             # need an empty commit
888             patch.set_bottom(head, backup = True)
889             patch.set_top(head, backup = True)
890             modified = True
891         elif head == bottom:
892             # reset the backup information. No need for logging
893             patch.set_bottom(bottom, backup = True)
894             patch.set_top(top, backup = True)
895
896             git.switch(top)
897         else:
898             # new patch needs to be refreshed.
899             # The current patch is empty after merge.
900             patch.set_bottom(head, backup = True)
901             patch.set_top(head, backup = True)
902
903             # Try the fast applying first. If this fails, fall back to the
904             # three-way merge
905             if not git.apply_diff(bottom, top):
906                 # if git.apply_diff() fails, the patch requires a diff3
907                 # merge and can be reported as modified
908                 modified = True
909
910                 # merge can fail but the patch needs to be pushed
911                 try:
912                     git.merge(bottom, head, top)
913                 except git.GitException, ex:
914                     print >> sys.stderr, \
915                           'The merge failed during "push". ' \
916                           'Use "refresh" after fixing the conflicts'
917
918         append_string(self.__applied_file, name)
919
920         unapplied.remove(name)
921         f = file(self.__unapplied_file, 'w+')
922         f.writelines([line + '\n' for line in unapplied])
923         f.close()
924
925         self.__set_current(name)
926
927         # head == bottom case doesn't need to refresh the patch
928         if empty or head != bottom:
929             if not ex:
930                 # if the merge was OK and no conflicts, just refresh the patch
931                 # The GIT cache was already updated by the merge operation
932                 if modified:
933                     log = 'push(m)'
934                 else:
935                     log = 'push'
936                 self.refresh_patch(cache_update = False, log = log)
937             else:
938                 raise StackException, str(ex)
939
940         return modified
941
942     def undo_push(self):
943         name = self.get_current()
944         assert(name)
945
946         patch = Patch(name, self.__patch_dir, self.__refs_dir)
947         old_bottom = patch.get_old_bottom()
948         old_top = patch.get_old_top()
949
950         # the top of the patch is changed by a push operation only
951         # together with the bottom (otherwise the top was probably
952         # modified by 'refresh'). If they are both unchanged, there
953         # was a fast forward
954         if old_bottom == patch.get_bottom() and old_top != patch.get_top():
955             raise StackException, 'No push undo information available'
956
957         git.reset()
958         self.pop_patch(name)
959         ret = patch.restore_old_boundaries()
960         if ret:
961             self.log_patch(patch, 'undo')
962
963         return ret
964
965     def pop_patch(self, name, keep = False):
966         """Pops the top patch from the stack
967         """
968         applied = self.get_applied()
969         applied.reverse()
970         assert(name in applied)
971
972         patch = Patch(name, self.__patch_dir, self.__refs_dir)
973
974         git.switch(patch.get_bottom(), keep)
975
976         # save the new applied list
977         idx = applied.index(name) + 1
978
979         popped = applied[:idx]
980         popped.reverse()
981         unapplied = popped + self.get_unapplied()
982
983         f = file(self.__unapplied_file, 'w+')
984         f.writelines([line + '\n' for line in unapplied])
985         f.close()
986
987         del applied[:idx]
988         applied.reverse()
989
990         f = file(self.__applied_file, 'w+')
991         f.writelines([line + '\n' for line in applied])
992         f.close()
993
994         if applied == []:
995             self.__set_current(None)
996         else:
997             self.__set_current(applied[-1])
998
999         self.__end_stack_check()
1000
1001     def empty_patch(self, name):
1002         """Returns True if the patch is empty
1003         """
1004         patch = Patch(name, self.__patch_dir, self.__refs_dir)
1005         bottom = patch.get_bottom()
1006         top = patch.get_top()
1007
1008         if bottom == top:
1009             return True
1010         elif git.get_commit(top).get_tree() \
1011                  == git.get_commit(bottom).get_tree():
1012             return True
1013
1014         return False
1015
1016     def rename_patch(self, oldname, newname):
1017         applied = self.get_applied()
1018         unapplied = self.get_unapplied()
1019
1020         if oldname == newname:
1021             raise StackException, '"To" name and "from" name are the same'
1022
1023         if newname in applied or newname in unapplied:
1024             raise StackException, 'Patch "%s" already exists' % newname
1025
1026         if oldname in unapplied:
1027             Patch(oldname, self.__patch_dir, self.__refs_dir).rename(newname)
1028             unapplied[unapplied.index(oldname)] = newname
1029
1030             f = file(self.__unapplied_file, 'w+')
1031             f.writelines([line + '\n' for line in unapplied])
1032             f.close()
1033         elif oldname in applied:
1034             Patch(oldname, self.__patch_dir, self.__refs_dir).rename(newname)
1035             if oldname == self.get_current():
1036                 self.__set_current(newname)
1037
1038             applied[applied.index(oldname)] = newname
1039
1040             f = file(self.__applied_file, 'w+')
1041             f.writelines([line + '\n' for line in applied])
1042             f.close()
1043         else:
1044             raise StackException, 'Unknown patch "%s"' % oldname
1045
1046     def log_patch(self, patch, message):
1047         """Generate a log commit for a patch
1048         """
1049         top = git.get_commit(patch.get_top())
1050         msg = '%s\t%s' % (message, top.get_id_hash())
1051
1052         old_log = patch.get_log()
1053         if old_log:
1054             parents = [old_log]
1055         else:
1056             parents = []
1057
1058         log = git.commit(message = msg, parents = parents,
1059                          cache_update = False, tree_id = top.get_tree(),
1060                          allowempty = True)
1061         patch.set_log(log)