git-merge-recursive.py

   1 #!/usr/bin/python
   2 #
   3 # Copyright (C) 2005 Fredrik Kuivinen
   4 #
   5
   6 import sys
   7 sys.path.append('''@@GIT_PYTHON_PATH@@''')
   8
   9 import math, random, os, re, signal, tempfile, stat, errno, traceback
  10 from heapq import heappush, heappop
  11 from sets import Set
  12
  13 from gitMergeCommon import *
  14
  15 outputIndent = 0
  16 def output(*args):
  17     sys.stdout.write('  '*outputIndent)
  18     printList(args)
  19
  20 originalIndexFile = os.environ.get('GIT_INDEX_FILE',
  21                                    os.environ.get('GIT_DIR', '.git') + '/index')
  22 temporaryIndexFile = os.environ.get('GIT_DIR', '.git') + \
  23                      '/merge-recursive-tmp-index'
  24 def setupIndex(temporary):
  25     try:
  26         os.unlink(temporaryIndexFile)
  27     except OSError:
  28         pass
  29     if temporary:
  30         newIndex = temporaryIndexFile
  31     else:
  32         newIndex = originalIndexFile
  33     os.environ['GIT_INDEX_FILE'] = newIndex
  34
  35 # This is a global variable which is used in a number of places but
  36 # only written to in the 'merge' function.
  37
  38 # cacheOnly == True  => Don't leave any non-stage 0 entries in the cache and
  39 #                       don't update the working directory.
  40 #              False => Leave unmerged entries in the cache and update
  41 #                       the working directory.
  42
  43 cacheOnly = False
  44
  45 # The entry point to the merge code
  46 # ---------------------------------
  47
  48 def merge(h1, h2, branch1Name, branch2Name, graph, callDepth=0):
  49     '''Merge the commits h1 and h2, return the resulting virtual
  50     commit object and a flag indicating the cleaness of the merge.'''
  51     assert(isinstance(h1, Commit) and isinstance(h2, Commit))
  52     assert(isinstance(graph, Graph))
  53
  54     global outputIndent
  55
  56     output('Merging:')
  57     output(h1)
  58     output(h2)
  59     sys.stdout.flush()
  60
  61     ca = getCommonAncestors(graph, h1, h2)
  62     output('found', len(ca), 'common ancestor(s):')
  63     for x in ca:
  64         output(x)
  65     sys.stdout.flush()
  66
  67     mergedCA = ca[0]
  68     for h in ca[1:]:
  69         outputIndent = callDepth+1
  70         [mergedCA, dummy] = merge(mergedCA, h,
  71                                   'Temporary merge branch 1',
  72                                   'Temporary merge branch 2',
  73                                   graph, callDepth+1)
  74         outputIndent = callDepth
  75         assert(isinstance(mergedCA, Commit))
  76
  77     global cacheOnly
  78     if callDepth == 0:
  79         setupIndex(False)
  80         cacheOnly = False
  81     else:
  82         setupIndex(True)
  83         runProgram(['git-read-tree', h1.tree()])
  84         cacheOnly = True
  85
  86     [shaRes, clean] = mergeTrees(h1.tree(), h2.tree(), mergedCA.tree(),
  87                                  branch1Name, branch2Name)
  88
  89     if clean or cacheOnly:
  90         res = Commit(None, [h1, h2], tree=shaRes)
  91         graph.addNode(res)
  92     else:
  93         res = None
  94
  95     return [res, clean]
  96
  97 getFilesRE = re.compile(r'^([0-7]+) (\S+) ([0-9a-f]{40})\t(.*)$', re.S)
  98 def getFilesAndDirs(tree):
  99     files = Set()
 100     dirs = Set()
 101     out = runProgram(['git-ls-tree', '-r', '-z', tree])
 102     for l in out.split('\0'):
 103         m = getFilesRE.match(l)
 104         if m:
 105             if m.group(2) == 'tree':
 106                 dirs.add(m.group(4))
 107             elif m.group(2) == 'blob':
 108                 files.add(m.group(4))
 109
 110     return [files, dirs]
 111
 112 # Those two global variables are used in a number of places but only
 113 # written to in 'mergeTrees' and 'uniquePath'. They keep track of
 114 # every file and directory in the two branches that are about to be
 115 # merged.
 116 currentFileSet = None
 117 currentDirectorySet = None
 118
 119 def mergeTrees(head, merge, common, branch1Name, branch2Name):
 120     '''Merge the trees 'head' and 'merge' with the common ancestor
 121     'common'. The name of the head branch is 'branch1Name' and the name of
 122     the merge branch is 'branch2Name'. Return a tuple (tree, cleanMerge)
 123     where tree is the resulting tree and cleanMerge is True iff the
 124     merge was clean.'''
 125
 126     assert(isSha(head) and isSha(merge) and isSha(common))
 127
 128     if common == merge:
 129         output('Already uptodate!')
 130         return [head, True]
 131
 132     if cacheOnly:
 133         updateArg = '-i'
 134     else:
 135         updateArg = '-u'
 136
 137     [out, code] = runProgram(['git-read-tree', updateArg, '-m',
 138                                 common, head, merge], returnCode = True)
 139     if code != 0:
 140         die('git-read-tree:', out)
 141
 142     [tree, code] = runProgram('git-write-tree', returnCode=True)
 143     tree = tree.rstrip()
 144     if code != 0:
 145         global currentFileSet, currentDirectorySet
 146         [currentFileSet, currentDirectorySet] = getFilesAndDirs(head)
 147         [filesM, dirsM] = getFilesAndDirs(merge)
 148         currentFileSet.union_update(filesM)
 149         currentDirectorySet.union_update(dirsM)
 150
 151         entries = unmergedCacheEntries()
 152         renamesHead =  getRenames(head, common, head, merge, entries)
 153         renamesMerge = getRenames(merge, common, head, merge, entries)
 154
 155         cleanMerge = processRenames(renamesHead, renamesMerge,
 156                                     branch1Name, branch2Name)
 157         for entry in entries:
 158             if entry.processed:
 159                 continue
 160             if not processEntry(entry, branch1Name, branch2Name):
 161                 cleanMerge = False
 162
 163         if cleanMerge or cacheOnly:
 164             tree = runProgram('git-write-tree').rstrip()
 165         else:
 166             tree = None
 167     else:
 168         cleanMerge = True
 169
 170     return [tree, cleanMerge]
 171
 172 # Low level file merging, update and removal
 173 # ------------------------------------------
 174
 175 def mergeFile(oPath, oSha, oMode, aPath, aSha, aMode, bPath, bSha, bMode,
 176               branch1Name, branch2Name):
 177
 178     merge = False
 179     clean = True
 180
 181     if stat.S_IFMT(aMode) != stat.S_IFMT(bMode):
 182         clean = False
 183         if stat.S_ISREG(aMode):
 184             mode = aMode
 185             sha = aSha
 186         else:
 187             mode = bMode
 188             sha = bSha
 189     else:
 190         if aSha != oSha and bSha != oSha:
 191             merge = True
 192
 193         if aMode == oMode:
 194             mode = bMode
 195         else:
 196             mode = aMode
 197
 198         if aSha == oSha:
 199             sha = bSha
 200         elif bSha == oSha:
 201             sha = aSha
 202         elif stat.S_ISREG(aMode):
 203             assert(stat.S_ISREG(bMode))
 204
 205             orig = runProgram(['git-unpack-file', oSha]).rstrip()
 206             src1 = runProgram(['git-unpack-file', aSha]).rstrip()
 207             src2 = runProgram(['git-unpack-file', bSha]).rstrip()
 208             [out, code] = runProgram(['merge',
 209                                       '-L', branch1Name + '/' + aPath,
 210                                       '-L', 'orig/' + oPath,
 211                                       '-L', branch2Name + '/' + bPath,
 212                                       src1, orig, src2], returnCode=True)
 213
 214             sha = runProgram(['git-hash-object', '-t', 'blob', '-w',
 215                               src1]).rstrip()
 216
 217             os.unlink(orig)
 218             os.unlink(src1)
 219             os.unlink(src2)
 220
 221             clean = (code == 0)
 222         else:
 223             assert(stat.S_ISLNK(aMode) and stat.S_ISLNK(bMode))
 224             sha = aSha
 225
 226             if aSha != bSha:
 227                 clean = False
 228
 229     return [sha, mode, clean, merge]
 230
 231 def updateFile(clean, sha, mode, path):
 232     updateCache = cacheOnly or clean
 233     updateWd = not cacheOnly
 234
 235     return updateFileExt(sha, mode, path, updateCache, updateWd)
 236
 237 def updateFileExt(sha, mode, path, updateCache, updateWd):
 238     if cacheOnly:
 239         updateWd = False
 240
 241     if updateWd:
 242         pathComponents = path.split('/')
 243         for x in xrange(1, len(pathComponents)):
 244             p = '/'.join(pathComponents[0:x])
 245
 246             try:
 247                 createDir = not stat.S_ISDIR(os.lstat(p).st_mode)
 248             except OSError:
 249                 createDir = True
 250
 251             if createDir:
 252                 try:
 253                     os.mkdir(p)
 254                 except OSError, e:
 255                     die("Couldn't create directory", p, e.strerror)
 256
 257         prog = ['git-cat-file', 'blob', sha]
 258         if stat.S_ISREG(mode):
 259             try:
 260                 os.unlink(path)
 261             except OSError:
 262                 pass
 263             if mode & 0100:
 264                 mode = 0777
 265             else:
 266                 mode = 0666
 267             fd = os.open(path, os.O_WRONLY | os.O_TRUNC | os.O_CREAT, mode)
 268             proc = subprocess.Popen(prog, stdout=fd)
 269             proc.wait()
 270             os.close(fd)
 271         elif stat.S_ISLNK(mode):
 272             linkTarget = runProgram(prog)
 273             os.symlink(linkTarget, path)
 274         else:
 275             assert(False)
 276
 277     if updateWd and updateCache:
 278         runProgram(['git-update-index', '--add', '--', path])
 279     elif updateCache:
 280         runProgram(['git-update-index', '--add', '--cacheinfo',
 281                     '0%o' % mode, sha, path])
 282
 283 def removeFile(clean, path):
 284     updateCache = cacheOnly or clean
 285     updateWd = not cacheOnly
 286
 287     if updateCache:
 288         runProgram(['git-update-index', '--force-remove', '--', path])
 289
 290     if updateWd:
 291         try:
 292             os.unlink(path)
 293         except OSError, e:
 294             if e.errno != errno.ENOENT and e.errno != errno.EISDIR:
 295                 raise
 296         try:
 297             os.removedirs(os.path.dirname(path))
 298         except OSError:
 299             pass
 300
 301 def uniquePath(path, branch):
 302     def fileExists(path):
 303         try:
 304             os.lstat(path)
 305             return True
 306         except OSError, e:
 307             if e.errno == errno.ENOENT:
 308                 return False
 309             else:
 310                 raise
 311
 312     branch = branch.replace('/', '_')
 313     newPath = path + '~' + branch
 314     suffix = 0
 315     while newPath in currentFileSet or \
 316           newPath in currentDirectorySet  or \
 317           fileExists(newPath):
 318         suffix += 1
 319         newPath = path + '~' + branch + '_' + str(suffix)
 320     currentFileSet.add(newPath)
 321     return newPath
 322
 323 # Cache entry management
 324 # ----------------------
 325
 326 class CacheEntry:
 327     def __init__(self, path):
 328         class Stage:
 329             def __init__(self):
 330                 self.sha1 = None
 331                 self.mode = None
 332
 333             # Used for debugging only
 334             def __str__(self):
 335                 if self.mode != None:
 336                     m = '0%o' % self.mode
 337                 else:
 338                     m = 'None'
 339
 340                 if self.sha1:
 341                     sha1 = self.sha1
 342                 else:
 343                     sha1 = 'None'
 344                 return 'sha1: ' + sha1 + ' mode: ' + m
 345
 346         self.stages = [Stage(), Stage(), Stage(), Stage()]
 347         self.path = path
 348         self.processed = False
 349
 350     def __str__(self):
 351         return 'path: ' + self.path + ' stages: ' + repr([str(x) for x in self.stages])
 352
 353 class CacheEntryContainer:
 354     def __init__(self):
 355         self.entries = {}
 356
 357     def add(self, entry):
 358         self.entries[entry.path] = entry
 359
 360     def get(self, path):
 361         return self.entries.get(path)
 362
 363     def __iter__(self):
 364         return self.entries.itervalues()
 365
 366 unmergedRE = re.compile(r'^([0-7]+) ([0-9a-f]{40}) ([1-3])\t(.*)$', re.S)
 367 def unmergedCacheEntries():
 368     '''Create a dictionary mapping file names to CacheEntry
 369     objects. The dictionary contains one entry for every path with a
 370     non-zero stage entry.'''
 371
 372     lines = runProgram(['git-ls-files', '-z', '--unmerged']).split('\0')
 373     lines.pop()
 374
 375     res = CacheEntryContainer()
 376     for l in lines:
 377         m = unmergedRE.match(l)
 378         if m:
 379             mode = int(m.group(1), 8)
 380             sha1 = m.group(2)
 381             stage = int(m.group(3))
 382             path = m.group(4)
 383
 384             e = res.get(path)
 385             if not e:
 386                 e = CacheEntry(path)
 387                 res.add(e)
 388
 389             e.stages[stage].mode = mode
 390             e.stages[stage].sha1 = sha1
 391         else:
 392             die('Error: Merge program failed: Unexpected output from',
 393                 'git-ls-files:', l)
 394     return res
 395
 396 lsTreeRE = re.compile(r'^([0-7]+) (\S+) ([0-9a-f]{40})\t(.*)\n$', re.S)
 397 def getCacheEntry(path, origTree, aTree, bTree):
 398     '''Returns a CacheEntry object which doesn't have to correspond to
 399     a real cache entry in Git's index.'''
 400
 401     def parse(out):
 402         if out == '':
 403             return [None, None]
 404         else:
 405             m = lsTreeRE.match(out)
 406             if not m:
 407                 die('Unexpected output from git-ls-tree:', out)
 408             elif m.group(2) == 'blob':
 409                 return [m.group(3), int(m.group(1), 8)]
 410             else:
 411                 return [None, None]
 412
 413     res = CacheEntry(path)
 414
 415     [oSha, oMode] = parse(runProgram(['git-ls-tree', origTree, '--', path]))
 416     [aSha, aMode] = parse(runProgram(['git-ls-tree', aTree, '--', path]))
 417     [bSha, bMode] = parse(runProgram(['git-ls-tree', bTree, '--', path]))
 418
 419     res.stages[1].sha1 = oSha
 420     res.stages[1].mode = oMode
 421     res.stages[2].sha1 = aSha
 422     res.stages[2].mode = aMode
 423     res.stages[3].sha1 = bSha
 424     res.stages[3].mode = bMode
 425
 426     return res
 427
 428 # Rename detection and handling
 429 # -----------------------------
 430
 431 class RenameEntry:
 432     def __init__(self,
 433                  src, srcSha, srcMode, srcCacheEntry,
 434                  dst, dstSha, dstMode, dstCacheEntry,
 435                  score):
 436         self.srcName = src
 437         self.srcSha = srcSha
 438         self.srcMode = srcMode
 439         self.srcCacheEntry = srcCacheEntry
 440         self.dstName = dst
 441         self.dstSha = dstSha
 442         self.dstMode = dstMode
 443         self.dstCacheEntry = dstCacheEntry
 444         self.score = score
 445
 446         self.processed = False
 447
 448 class RenameEntryContainer:
 449     def __init__(self):
 450         self.entriesSrc = {}
 451         self.entriesDst = {}
 452
 453     def add(self, entry):
 454         self.entriesSrc[entry.srcName] = entry
 455         self.entriesDst[entry.dstName] = entry
 456
 457     def getSrc(self, path):
 458         return self.entriesSrc.get(path)
 459
 460     def getDst(self, path):
 461         return self.entriesDst.get(path)
 462
 463     def __iter__(self):
 464         return self.entriesSrc.itervalues()
 465
 466 parseDiffRenamesRE = re.compile('^:([0-7]+) ([0-7]+) ([0-9a-f]{40}) ([0-9a-f]{40}) R([0-9]*)$')
 467 def getRenames(tree, oTree, aTree, bTree, cacheEntries):
 468     '''Get information of all renames which occured between 'oTree' and
 469     'tree'. We need the three trees in the merge ('oTree', 'aTree' and
 470     'bTree') to be able to associate the correct cache entries with
 471     the rename information. 'tree' is always equal to either aTree or bTree.'''
 472
 473     assert(tree == aTree or tree == bTree)
 474     inp = runProgram(['git-diff-tree', '-M', '--diff-filter=R', '-r',
 475                       '-z', oTree, tree])
 476
 477     ret = RenameEntryContainer()
 478     try:
 479         recs = inp.split("\0")
 480         recs.pop() # remove last entry (which is '')
 481         it = recs.__iter__()
 482         while True:
 483             rec = it.next()
 484             m = parseDiffRenamesRE.match(rec)
 485
 486             if not m:
 487                 die('Unexpected output from git-diff-tree:', rec)
 488
 489             srcMode = int(m.group(1), 8)
 490             dstMode = int(m.group(2), 8)
 491             srcSha = m.group(3)
 492             dstSha = m.group(4)
 493             score = m.group(5)
 494             src = it.next()
 495             dst = it.next()
 496
 497             srcCacheEntry = cacheEntries.get(src)
 498             if not srcCacheEntry:
 499                 srcCacheEntry = getCacheEntry(src, oTree, aTree, bTree)
 500                 cacheEntries.add(srcCacheEntry)
 501
 502             dstCacheEntry = cacheEntries.get(dst)
 503             if not dstCacheEntry:
 504                 dstCacheEntry = getCacheEntry(dst, oTree, aTree, bTree)
 505                 cacheEntries.add(dstCacheEntry)
 506
 507             ret.add(RenameEntry(src, srcSha, srcMode, srcCacheEntry,
 508                                 dst, dstSha, dstMode, dstCacheEntry,
 509                                 score))
 510     except StopIteration:
 511         pass
 512     return ret
 513
 514 def fmtRename(src, dst):
 515     srcPath = src.split('/')
 516     dstPath = dst.split('/')
 517     path = []
 518     endIndex = min(len(srcPath), len(dstPath)) - 1
 519     for x in range(0, endIndex):
 520         if srcPath[x] == dstPath[x]:
 521             path.append(srcPath[x])
 522         else:
 523             endIndex = x
 524             break
 525
 526     if len(path) > 0:
 527         return '/'.join(path) + \
 528                '/{' + '/'.join(srcPath[endIndex:]) + ' => ' + \
 529                '/'.join(dstPath[endIndex:]) + '}'
 530     else:
 531         return src + ' => ' + dst
 532
 533 def processRenames(renamesA, renamesB, branchNameA, branchNameB):
 534     srcNames = Set()
 535     for x in renamesA:
 536         srcNames.add(x.srcName)
 537     for x in renamesB:
 538         srcNames.add(x.srcName)
 539
 540     cleanMerge = True
 541     for path in srcNames:
 542         if renamesA.getSrc(path):
 543             renames1 = renamesA
 544             renames2 = renamesB
 545             branchName1 = branchNameA
 546             branchName2 = branchNameB
 547         else:
 548             renames1 = renamesB
 549             renames2 = renamesA
 550             branchName1 = branchNameB
 551             branchName2 = branchNameA
 552
 553         ren1 = renames1.getSrc(path)
 554         ren2 = renames2.getSrc(path)
 555
 556         ren1.dstCacheEntry.processed = True
 557         ren1.srcCacheEntry.processed = True
 558
 559         if ren1.processed:
 560             continue
 561
 562         ren1.processed = True
 563         removeFile(True, ren1.srcName)
 564         if ren2:
 565             # Renamed in 1 and renamed in 2
 566             assert(ren1.srcName == ren2.srcName)
 567             ren2.dstCacheEntry.processed = True
 568             ren2.processed = True
 569
 570             if ren1.dstName != ren2.dstName:
 571                 output('CONFLICT (rename/rename): Rename',
 572                        fmtRename(path, ren1.dstName), 'in branch', branchName1,
 573                        'rename', fmtRename(path, ren2.dstName), 'in',
 574                        branchName2)
 575                 cleanMerge = False
 576
 577                 if ren1.dstName in currentDirectorySet:
 578                     dstName1 = uniquePath(ren1.dstName, branchName1)
 579                     output(ren1.dstName, 'is a directory in', branchName2,
 580                            'adding as', dstName1, 'instead.')
 581                     removeFile(False, ren1.dstName)
 582                 else:
 583                     dstName1 = ren1.dstName
 584
 585                 if ren2.dstName in currentDirectorySet:
 586                     dstName2 = uniquePath(ren2.dstName, branchName2)
 587                     output(ren2.dstName, 'is a directory in', branchName1,
 588                            'adding as', dstName2, 'instead.')
 589                     removeFile(False, ren2.dstName)
 590                 else:
 591                     dstName2 = ren1.dstName
 592
 593                 updateFile(False, ren1.dstSha, ren1.dstMode, dstName1)
 594                 updateFile(False, ren2.dstSha, ren2.dstMode, dstName2)
 595             else:
 596                 [resSha, resMode, clean, merge] = \
 597                          mergeFile(ren1.srcName, ren1.srcSha, ren1.srcMode,
 598                                    ren1.dstName, ren1.dstSha, ren1.dstMode,
 599                                    ren2.dstName, ren2.dstSha, ren2.dstMode,
 600                                    branchName1, branchName2)
 601
 602                 if merge or not clean:
 603                     output('Renaming', fmtRename(path, ren1.dstName))
 604
 605                 if merge:
 606                     output('Auto-merging', ren1.dstName)
 607
 608                 if not clean:
 609                     output('CONFLICT (content): merge conflict in',
 610                            ren1.dstName)
 611                     cleanMerge = False
 612
 613                     if not cacheOnly:
 614                         updateFileExt(ren1.dstSha, ren1.dstMode, ren1.dstName,
 615                                       updateCache=True, updateWd=False)
 616                 updateFile(clean, resSha, resMode, ren1.dstName)
 617         else:
 618             # Renamed in 1, maybe changed in 2
 619             if renamesA == renames1:
 620                 stage = 3
 621             else:
 622                 stage = 2
 623
 624             srcShaOtherBranch  = ren1.srcCacheEntry.stages[stage].sha1
 625             srcModeOtherBranch = ren1.srcCacheEntry.stages[stage].mode
 626
 627             dstShaOtherBranch  = ren1.dstCacheEntry.stages[stage].sha1
 628             dstModeOtherBranch = ren1.dstCacheEntry.stages[stage].mode
 629
 630             tryMerge = False
 631
 632             if ren1.dstName in currentDirectorySet:
 633                 newPath = uniquePath(ren1.dstName, branchName1)
 634                 output('CONFLICT (rename/directory): Rename',
 635                        fmtRename(ren1.srcName, ren1.dstName), 'in', branchName1,
 636                        'directory', ren1.dstName, 'added in', branchName2)
 637                 output('Renaming', ren1.srcName, 'to', newPath, 'instead')
 638                 cleanMerge = False
 639                 removeFile(False, ren1.dstName)
 640                 updateFile(False, ren1.dstSha, ren1.dstMode, newPath)
 641             elif srcShaOtherBranch == None:
 642                 output('CONFLICT (rename/delete): Rename',
 643                        fmtRename(ren1.srcName, ren1.dstName), 'in',
 644                        branchName1, 'and deleted in', branchName2)
 645                 cleanMerge = False
 646                 updateFile(False, ren1.dstSha, ren1.dstMode, ren1.dstName)
 647             elif dstShaOtherBranch:
 648                 newPath = uniquePath(ren1.dstName, branchName2)
 649                 output('CONFLICT (rename/add): Rename',
 650                        fmtRename(ren1.srcName, ren1.dstName), 'in',
 651                        branchName1 + '.', ren1.dstName, 'added in', branchName2)
 652                 output('Adding as', newPath, 'instead')
 653                 updateFile(False, dstShaOtherBranch, dstModeOtherBranch, newPath)
 654                 cleanMerge = False
 655                 tryMerge = True
 656             elif renames2.getDst(ren1.dstName):
 657                 dst2 = renames2.getDst(ren1.dstName)
 658                 newPath1 = uniquePath(ren1.dstName, branchName1)
 659                 newPath2 = uniquePath(dst2.dstName, branchName2)
 660                 output('CONFLICT (rename/rename): Rename',
 661                        fmtRename(ren1.srcName, ren1.dstName), 'in',
 662                        branchName1+'. Rename',
 663                        fmtRename(dst2.srcName, dst2.dstName), 'in', branchName2)
 664                 output('Renaming', ren1.srcName, 'to', newPath1, 'and',
 665                        dst2.srcName, 'to', newPath2, 'instead')
 666                 removeFile(False, ren1.dstName)
 667                 updateFile(False, ren1.dstSha, ren1.dstMode, newPath1)
 668                 updateFile(False, dst2.dstSha, dst2.dstMode, newPath2)
 669                 dst2.processed = True
 670                 cleanMerge = False
 671             else:
 672                 tryMerge = True
 673
 674             if tryMerge:
 675                 [resSha, resMode, clean, merge] = \
 676                          mergeFile(ren1.srcName, ren1.srcSha, ren1.srcMode,
 677                                    ren1.dstName, ren1.dstSha, ren1.dstMode,
 678                                    ren1.srcName, srcShaOtherBranch, srcModeOtherBranch,
 679                                    branchName1, branchName2)
 680
 681                 if merge or not clean:
 682                     output('Renaming', fmtRename(ren1.srcName, ren1.dstName))
 683
 684                 if merge:
 685                     output('Auto-merging', ren1.dstName)
 686
 687                 if not clean:
 688                     output('CONFLICT (rename/modify): Merge conflict in',
 689                            ren1.dstName)
 690                     cleanMerge = False
 691
 692                     if not cacheOnly:
 693                         updateFileExt(ren1.dstSha, ren1.dstMode, ren1.dstName,
 694                                       updateCache=True, updateWd=False)
 695                 updateFile(clean, resSha, resMode, ren1.dstName)
 696
 697     return cleanMerge
 698
 699 # Per entry merge function
 700 # ------------------------
 701
 702 def processEntry(entry, branch1Name, branch2Name):
 703     '''Merge one cache entry.'''
 704
 705     debug('processing', entry.path, 'clean cache:', cacheOnly)
 706
 707     cleanMerge = True
 708
 709     path = entry.path
 710     oSha = entry.stages[1].sha1
 711     oMode = entry.stages[1].mode
 712     aSha = entry.stages[2].sha1
 713     aMode = entry.stages[2].mode
 714     bSha = entry.stages[3].sha1
 715     bMode = entry.stages[3].mode
 716
 717     assert(oSha == None or isSha(oSha))
 718     assert(aSha == None or isSha(aSha))
 719     assert(bSha == None or isSha(bSha))
 720
 721     assert(oMode == None or type(oMode) is int)
 722     assert(aMode == None or type(aMode) is int)
 723     assert(bMode == None or type(bMode) is int)
 724
 725     if (oSha and (not aSha or not bSha)):
 726     #
 727     # Case A: Deleted in one
 728     #
 729         if (not aSha     and not bSha) or \
 730            (aSha == oSha and not bSha) or \
 731            (not aSha     and bSha == oSha):
 732     # Deleted in both or deleted in one and unchanged in the other
 733             if aSha:
 734                 output('Removing', path)
 735             removeFile(True, path)
 736         else:
 737     # Deleted in one and changed in the other
 738             cleanMerge = False
 739             if not aSha:
 740                 output('CONFLICT (delete/modify):', path, 'deleted in',
 741                        branch1Name, 'and modified in', branch2Name + '.',
 742                        'Version', branch2Name, 'of', path, 'left in tree.')
 743                 mode = bMode
 744                 sha = bSha
 745             else:
 746                 output('CONFLICT (modify/delete):', path, 'deleted in',
 747                        branch2Name, 'and modified in', branch1Name + '.',
 748                        'Version', branch1Name, 'of', path, 'left in tree.')
 749                 mode = aMode
 750                 sha = aSha
 751
 752             updateFile(False, sha, mode, path)
 753
 754     elif (not oSha and aSha     and not bSha) or \
 755          (not oSha and not aSha and bSha):
 756     #
 757     # Case B: Added in one.
 758     #
 759         if aSha:
 760             addBranch = branch1Name
 761             otherBranch = branch2Name
 762             mode = aMode
 763             sha = aSha
 764             conf = 'file/directory'
 765         else:
 766             addBranch = branch2Name
 767             otherBranch = branch1Name
 768             mode = bMode
 769             sha = bSha
 770             conf = 'directory/file'
 771
 772         if path in currentDirectorySet:
 773             cleanMerge = False
 774             newPath = uniquePath(path, addBranch)
 775             output('CONFLICT (' + conf + '):',
 776                    'There is a directory with name', path, 'in',
 777                    otherBranch + '. Adding', path, 'as', newPath)
 778
 779             removeFile(False, path)
 780             updateFile(False, sha, mode, newPath)
 781         else:
 782             output('Adding', path)
 783             updateFile(True, sha, mode, path)
 784
 785     elif not oSha and aSha and bSha:
 786     #
 787     # Case C: Added in both (check for same permissions).
 788     #
 789         if aSha == bSha:
 790             if aMode != bMode:
 791                 cleanMerge = False
 792                 output('CONFLICT: File', path,
 793                        'added identically in both branches, but permissions',
 794                        'conflict', '0%o' % aMode, '->', '0%o' % bMode)
 795                 output('CONFLICT: adding with permission:', '0%o' % aMode)
 796
 797                 updateFile(False, aSha, aMode, path)
 798             else:
 799                 # This case is handled by git-read-tree
 800                 assert(False)
 801         else:
 802             cleanMerge = False
 803             newPath1 = uniquePath(path, branch1Name)
 804             newPath2 = uniquePath(path, branch2Name)
 805             output('CONFLICT (add/add): File', path,
 806                    'added non-identically in both branches. Adding as',
 807                    newPath1, 'and', newPath2, 'instead.')
 808             removeFile(False, path)
 809             updateFile(False, aSha, aMode, newPath1)
 810             updateFile(False, bSha, bMode, newPath2)
 811
 812     elif oSha and aSha and bSha:
 813     #
 814     # case D: Modified in both, but differently.
 815     #
 816         output('Auto-merging', path)
 817         [sha, mode, clean, dummy] = \
 818               mergeFile(path, oSha, oMode,
 819                         path, aSha, aMode,
 820                         path, bSha, bMode,
 821                         branch1Name, branch2Name)
 822         if clean:
 823             updateFile(True, sha, mode, path)
 824         else:
 825             cleanMerge = False
 826             output('CONFLICT (content): Merge conflict in', path)
 827
 828             if cacheOnly:
 829                 updateFile(False, sha, mode, path)
 830             else:
 831                 updateFileExt(aSha, aMode, path,
 832                               updateCache=True, updateWd=False)
 833                 updateFileExt(sha, mode, path, updateCache=False, updateWd=True)
 834     else:
 835         die("ERROR: Fatal merge failure, shouldn't happen.")
 836
 837     return cleanMerge
 838
 839 def usage():
 840     die('Usage:', sys.argv[0], ' <base>... -- <head> <remote>..')
 841
 842 # main entry point as merge strategy module
 843 # The first parameters up to -- are merge bases, and the rest are heads.
 844 # This strategy module figures out merge bases itself, so we only
 845 # get heads.
 846
 847 if len(sys.argv) < 4:
 848     usage()
 849
 850 for nextArg in xrange(1, len(sys.argv)):
 851     if sys.argv[nextArg] == '--':
 852         if len(sys.argv) != nextArg + 3:
 853             die('Not handling anything other than two heads merge.')
 854         try:
 855             h1 = firstBranch = sys.argv[nextArg + 1]
 856             h2 = secondBranch = sys.argv[nextArg + 2]
 857         except IndexError:
 858             usage()
 859         break
 860
 861 print 'Merging', h1, 'with', h2
 862
 863 try:
 864     h1 = runProgram(['git-rev-parse', '--verify', h1 + '^0']).rstrip()
 865     h2 = runProgram(['git-rev-parse', '--verify', h2 + '^0']).rstrip()
 866
 867     graph = buildGraph([h1, h2])
 868
 869     [dummy, clean] = merge(graph.shaMap[h1], graph.shaMap[h2],
 870                            firstBranch, secondBranch, graph)
 871
 872     print ''
 873 except:
 874     if isinstance(sys.exc_info()[1], SystemExit):
 875         raise
 876     else:
 877         traceback.print_exc(None, sys.stderr)
 878         sys.exit(2)
 879
 880 if clean:
 881     sys.exit(0)
 882 else:
 883     sys.exit(1)