mdw@git.distorted.org.uk Git - stgit/blob - stgit/gitmergeonefile.py

   1 """Performs a 3-way merge for GIT files
   2 """
   3
   4 __copyright__ = """
   5 Copyright (C) 2006, 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 from stgit.exception import *
  23 from stgit import basedir
  24 from stgit.config import config, file_extensions, ConfigOption
  25 from stgit.utils import append_string
  26 from stgit.out import *
  27 from stgit.run import *
  28
  29 class GitMergeException(StgException):
  30     pass
  31
  32
  33 #
  34 # Options
  35 #
  36 merger = ConfigOption('stgit', 'merger')
  37 keeporig = ConfigOption('stgit', 'keeporig')
  38
  39 #
  40 # Utility functions
  41 #
  42 def __str2none(x):
  43     if x == '':
  44         return None
  45     else:
  46         return x
  47
  48 class MRun(Run):
  49     exc = GitMergeException # use a custom exception class on errors
  50
  51 def __checkout_files(orig_hash, file1_hash, file2_hash,
  52                      path,
  53                      orig_mode, file1_mode, file2_mode):
  54     """Check out the files passed as arguments
  55     """
  56     global orig, src1, src2
  57
  58     extensions = file_extensions()
  59
  60     if orig_hash:
  61         orig = path + extensions['ancestor']
  62         tmp = MRun('git-unpack-file', orig_hash).output_one_line()
  63         os.chmod(tmp, int(orig_mode, 8))
  64         os.renames(tmp, orig)
  65     if file1_hash:
  66         src1 = path + extensions['current']
  67         tmp = MRun('git-unpack-file', file1_hash).output_one_line()
  68         os.chmod(tmp, int(file1_mode, 8))
  69         os.renames(tmp, src1)
  70     if file2_hash:
  71         src2 = path + extensions['patched']
  72         tmp = MRun('git-unpack-file', file2_hash).output_one_line()
  73         os.chmod(tmp, int(file2_mode, 8))
  74         os.renames(tmp, src2)
  75
  76     if file1_hash and not os.path.exists(path):
  77         # the current file might be removed by GIT when it is a new
  78         # file added in both branches. Just re-generate it
  79         tmp = MRun('git-unpack-file', file1_hash).output_one_line()
  80         os.chmod(tmp, int(file1_mode, 8))
  81         os.renames(tmp, path)
  82
  83 def __remove_files(orig_hash, file1_hash, file2_hash):
  84     """Remove any temporary files
  85     """
  86     if orig_hash:
  87         os.remove(orig)
  88     if file1_hash:
  89         os.remove(src1)
  90     if file2_hash:
  91         os.remove(src2)
  92
  93 def __conflict(path):
  94     """Write the conflict file for the 'path' variable and exit
  95     """
  96     append_string(os.path.join(basedir.get(), 'conflicts'), path)
  97
  98
  99 def interactive_merge(filename):
 100     """Run the interactive merger on the given file. Note that the
 101     index should not have any conflicts.
 102     """
 103     extensions = file_extensions()
 104
 105     ancestor = filename + extensions['ancestor']
 106     current = filename + extensions['current']
 107     patched = filename + extensions['patched']
 108
 109     if os.path.isfile(ancestor):
 110         three_way = True
 111         files_dict = {'branch1': current,
 112                       'ancestor': ancestor,
 113                       'branch2': patched,
 114                       'output': filename}
 115         imerger = config.get('stgit.i3merge')
 116     else:
 117         three_way = False
 118         files_dict = {'branch1': current,
 119                       'branch2': patched,
 120                       'output': filename}
 121         imerger = config.get('stgit.i2merge')
 122
 123     if not imerger:
 124         raise GitMergeException, 'No interactive merge command configured'
 125
 126     # check whether we have all the files for the merge
 127     for fn in [filename, current, patched]:
 128         if not os.path.isfile(fn):
 129             raise GitMergeException, \
 130                   'Cannot run the interactive merge: "%s" missing' % fn
 131
 132     mtime = os.path.getmtime(filename)
 133
 134     out.info('Trying the interactive %s merge'
 135              % (three_way and 'three-way' or 'two-way'))
 136
 137     err = os.system(imerger % files_dict)
 138     if err != 0:
 139         raise GitMergeException, 'The interactive merge failed: %d' % err
 140     if not os.path.isfile(filename):
 141         raise GitMergeException, 'The "%s" file is missing' % filename
 142     if mtime == os.path.getmtime(filename):
 143         raise GitMergeException, 'The "%s" file was not modified' % filename
 144
 145
 146 #
 147 # Main algorithm
 148 #
 149 def merge(orig_hash, file1_hash, file2_hash,
 150           path,
 151           orig_mode, file1_mode, file2_mode):
 152     """Three-way merge for one file algorithm
 153     """
 154     __checkout_files(orig_hash, file1_hash, file2_hash,
 155                      path,
 156                      orig_mode, file1_mode, file2_mode)
 157
 158     # file exists in origin
 159     if orig_hash:
 160         # modified in both
 161         if file1_hash and file2_hash:
 162             # if modes are the same (git-read-tree probably dealt with it)
 163             if file1_hash == file2_hash:
 164                 if os.system('git-update-index --cacheinfo %s %s %s'
 165                              % (file1_mode, file1_hash, path)) != 0:
 166                     out.error('git-update-index failed')
 167                     __conflict(path)
 168                     return 1
 169                 if os.system('git-checkout-index -u -f -- %s' % path):
 170                     out.error('git-checkout-index failed')
 171                     __conflict(path)
 172                     return 1
 173                 if file1_mode != file2_mode:
 174                     out.error('File added in both, permissions conflict')
 175                     __conflict(path)
 176                     return 1
 177             # 3-way merge
 178             else:
 179                 merge_ok = os.system(str(merger) % {'branch1': src1,
 180                                                     'ancestor': orig,
 181                                                     'branch2': src2,
 182                                                     'output': path }) == 0
 183
 184                 if merge_ok:
 185                     os.system('git-update-index -- %s' % path)
 186                     __remove_files(orig_hash, file1_hash, file2_hash)
 187                     return 0
 188                 else:
 189                     out.error('Three-way merge tool failed for file "%s"'
 190                               % path)
 191                     # reset the cache to the first branch
 192                     os.system('git-update-index --cacheinfo %s %s %s'
 193                               % (file1_mode, file1_hash, path))
 194
 195                     if config.get('stgit.autoimerge') == 'yes':
 196                         try:
 197                             interactive_merge(path)
 198                         except GitMergeException, ex:
 199                             # interactive merge failed
 200                             out.error(str(ex))
 201                             if str(keeporig) != 'yes':
 202                                 __remove_files(orig_hash, file1_hash,
 203                                                file2_hash)
 204                             __conflict(path)
 205                             return 1
 206                         # successful interactive merge
 207                         os.system('git-update-index -- %s' % path)
 208                         __remove_files(orig_hash, file1_hash, file2_hash)
 209                         return 0
 210                     else:
 211                         # no interactive merge, just mark it as conflict
 212                         if str(keeporig) != 'yes':
 213                             __remove_files(orig_hash, file1_hash, file2_hash)
 214                         __conflict(path)
 215                         return 1
 216
 217         # file deleted in both or deleted in one and unchanged in the other
 218         elif not (file1_hash or file2_hash) \
 219                or file1_hash == orig_hash or file2_hash == orig_hash:
 220             if os.path.exists(path):
 221                 os.remove(path)
 222             __remove_files(orig_hash, file1_hash, file2_hash)
 223             return os.system('git-update-index --remove -- %s' % path)
 224         # file deleted in one and changed in the other
 225         else:
 226             # Do something here - we must at least merge the entry in
 227             # the cache, instead of leaving it in U(nmerged) state. In
 228             # fact, stg resolved does not handle that.
 229
 230             # Do the same thing cogito does - remove the file in any case.
 231             os.system('git-update-index --remove -- %s' % path)
 232
 233             #if file1_hash:
 234                 ## file deleted upstream and changed in the patch. The
 235                 ## patch is probably going to move the changes
 236                 ## elsewhere.
 237
 238                 #os.system('git-update-index --remove -- %s' % path)
 239             #else:
 240                 ## file deleted in the patch and changed upstream. We
 241                 ## could re-delete it, but for now leave it there -
 242                 ## and let the user check if he still wants to remove
 243                 ## the file.
 244
 245                 ## reset the cache to the first branch
 246                 #os.system('git-update-index --cacheinfo %s %s %s'
 247                 #          % (file1_mode, file1_hash, path))
 248             __conflict(path)
 249             return 1
 250
 251     # file does not exist in origin
 252     else:
 253         # file added in both
 254         if file1_hash and file2_hash:
 255             # files are the same
 256             if file1_hash == file2_hash:
 257                 if os.system('git-update-index --add --cacheinfo %s %s %s'
 258                              % (file1_mode, file1_hash, path)) != 0:
 259                     out.error('git-update-index failed')
 260                     __conflict(path)
 261                     return 1
 262                 if os.system('git-checkout-index -u -f -- %s' % path):
 263                     out.error('git-checkout-index failed')
 264                     __conflict(path)
 265                     return 1
 266                 if file1_mode != file2_mode:
 267                     out.error('File "s" added in both, permissions conflict'
 268                               % path)
 269                     __conflict(path)
 270                     return 1
 271             # files added in both but different
 272             else:
 273                 out.error('File "%s" added in branches but different' % path)
 274                 # reset the cache to the first branch
 275                 os.system('git-update-index --cacheinfo %s %s %s'
 276                           % (file1_mode, file1_hash, path))
 277
 278                 if config.get('stgit.autoimerge') == 'yes':
 279                     try:
 280                         interactive_merge(path)
 281                     except GitMergeException, ex:
 282                         # interactive merge failed
 283                         out.error(str(ex))
 284                         if str(keeporig) != 'yes':
 285                             __remove_files(orig_hash, file1_hash,
 286                                            file2_hash)
 287                         __conflict(path)
 288                         return 1
 289                     # successful interactive merge
 290                     os.system('git-update-index -- %s' % path)
 291                     __remove_files(orig_hash, file1_hash, file2_hash)
 292                     return 0
 293                 else:
 294                     # no interactive merge, just mark it as conflict
 295                     if str(keeporig) != 'yes':
 296                         __remove_files(orig_hash, file1_hash, file2_hash)
 297                     __conflict(path)
 298                     return 1
 299         # file added in one
 300         elif file1_hash or file2_hash:
 301             if file1_hash:
 302                 mode = file1_mode
 303                 obj = file1_hash
 304             else:
 305                 mode = file2_mode
 306                 obj = file2_hash
 307             if os.system('git-update-index --add --cacheinfo %s %s %s'
 308                          % (mode, obj, path)) != 0:
 309                 out.error('git-update-index failed')
 310                 __conflict(path)
 311                 return 1
 312             __remove_files(orig_hash, file1_hash, file2_hash)
 313             return os.system('git-checkout-index -u -f -- %s' % path)
 314
 315     # Unhandled case
 316     out.error('Unhandled merge conflict: "%s" "%s" "%s" "%s" "%s" "%s" "%s"'
 317               % (orig_hash, file1_hash, file2_hash,
 318                  path,
 319                  orig_mode, file1_mode, file2_mode))
 320     __conflict(path)
 321     return 1