[stgit] / stgit / gitmergeonefile.py

"""Performs a 3-way merge for GIT files
"""

__copyright__ = """
Copyright (C) 2006, Catalin Marinas <catalin.marinas@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
"""

import sys, os
from stgit import basedir
from stgit.config import config, file_extensions, ConfigOption
from stgit.utils import append_string


class GitMergeException(Exception):
    pass


#
# Options
#
merger = ConfigOption('stgit', 'merger')
keeporig = ConfigOption('stgit', 'keeporig')

#
# Utility functions
#
def __str2none(x):
    if x == '':
        return None
    else:
        return x

def __output(cmd):
    f = os.popen(cmd, 'r')
    string = f.readline().rstrip()
    if f.close():
        raise GitMergeException, 'Error: failed to execute "%s"' % cmd
    return string

def __checkout_files(orig_hash, file1_hash, file2_hash,
                     path,
                     orig_mode, file1_mode, file2_mode):
    """Check out the files passed as arguments
    """
    global orig, src1, src2

    extensions = file_extensions()

    if orig_hash:
        orig = path + extensions['ancestor']
        tmp = __output('git-unpack-file %s' % orig_hash)
        os.chmod(tmp, int(orig_mode, 8))
        os.renames(tmp, orig)
    if file1_hash:
        src1 = path + extensions['current']
        tmp = __output('git-unpack-file %s' % file1_hash)
        os.chmod(tmp, int(file1_mode, 8))
        os.renames(tmp, src1)
    if file2_hash:
        src2 = path + extensions['patched']
        tmp = __output('git-unpack-file %s' % file2_hash)
        os.chmod(tmp, int(file2_mode, 8))
        os.renames(tmp, src2)

    if file1_hash and not os.path.exists(path):
        # the current file might be removed by GIT when it is a new
        # file added in both branches. Just re-generate it
        tmp = __output('git-unpack-file %s' % file1_hash)
        os.chmod(tmp, int(file1_mode, 8))
        os.renames(tmp, path)

def __remove_files(orig_hash, file1_hash, file2_hash):
    """Remove any temporary files
    """
    if orig_hash:
        os.remove(orig)
    if file1_hash:
        os.remove(src1)
    if file2_hash:
        os.remove(src2)

def __conflict(path):
    """Write the conflict file for the 'path' variable and exit
    """
    append_string(os.path.join(basedir.get(), 'conflicts'), path)


def interactive_merge(filename):
    """Run the interactive merger on the given file. Note that the
    index should not have any conflicts.
    """
    imerger = config.get('stgit.imerger')
    if not imerger:
        raise GitMergeException, 'Configuration error: %s' % err

    extensions = file_extensions()

    ancestor = filename + extensions['ancestor']
    current = filename + extensions['current']
    patched = filename + extensions['patched']

    # check whether we have all the files for a three-way merge
    for fn in [filename, ancestor, current, patched]:
        if not os.path.isfile(fn):
            raise GitMergeException, \
                  'Cannot run the interactive merger: "%s" missing' % fn

    mtime = os.path.getmtime(filename)

    err = os.system(imerger % {'branch1': current,
                               'ancestor': ancestor,
                               'branch2': patched,
                               'output': filename})

    if err != 0:
        raise GitMergeException, 'The interactive merge failed: %d' % err
    if not os.path.isfile(filename):
        raise GitMergeException, 'The "%s" file is missing' % filename
    if mtime == os.path.getmtime(filename):
        raise GitMergeException, 'The "%s" file was not modified' % filename


#
# Main algorithm
#
def merge(orig_hash, file1_hash, file2_hash,
          path,
          orig_mode, file1_mode, file2_mode):
    """Three-way merge for one file algorithm
    """
    __checkout_files(orig_hash, file1_hash, file2_hash,
                     path,
                     orig_mode, file1_mode, file2_mode)

    # file exists in origin
    if orig_hash:
        # modified in both
        if file1_hash and file2_hash:
            # if modes are the same (git-read-tree probably dealt with it)
            if file1_hash == file2_hash:
                if os.system('git-update-index --cacheinfo %s %s %s'
                             % (file1_mode, file1_hash, path)) != 0:
                    print >> sys.stderr, 'Error: git-update-index failed'
                    __conflict(path)
                    return 1
                if os.system('git-checkout-index -u -f -- %s' % path):
                    print >> sys.stderr, 'Error: git-checkout-index failed'
                    __conflict(path)
                    return 1
                if file1_mode != file2_mode:
                    print >> sys.stderr, \
                          'Error: File added in both, permissions conflict'
                    __conflict(path)
                    return 1
            # 3-way merge
            else:
                merge_ok = os.system(str(merger) % {'branch1': src1,
                                                    'ancestor': orig,
                                                    'branch2': src2,
                                                    'output': path }) == 0

                if merge_ok:
                    os.system('git-update-index -- %s' % path)
                    __remove_files(orig_hash, file1_hash, file2_hash)
                    return 0
                else:
                    print >> sys.stderr, \
                          'Error: three-way merge tool failed for file "%s"' \
                          % path
                    # reset the cache to the first branch
                    os.system('git-update-index --cacheinfo %s %s %s'
                              % (file1_mode, file1_hash, path))

                    if config.get('stgit.autoimerge') == 'yes':
                        print >> sys.stderr, \
                              'Trying the interactive merge'
                        try:
                            interactive_merge(path)
                        except GitMergeException, ex:
                            # interactive merge failed
                            print >> sys.stderr, str(ex)
                            if str(keeporig) != 'yes':
                                __remove_files(orig_hash, file1_hash,
                                               file2_hash)
                            __conflict(path)
                            return 1
                        # successful interactive merge
                        os.system('git-update-index -- %s' % path)
                        __remove_files(orig_hash, file1_hash, file2_hash)
                        return 0
                    else:
                        # no interactive merge, just mark it as conflict
                        if str(keeporig) != 'yes':
                            __remove_files(orig_hash, file1_hash, file2_hash)
                        __conflict(path)
                        return 1

        # file deleted in both or deleted in one and unchanged in the other
        elif not (file1_hash or file2_hash) \
               or file1_hash == orig_hash or file2_hash == orig_hash:
            if os.path.exists(path):
                os.remove(path)
            __remove_files(orig_hash, file1_hash, file2_hash)
            return os.system('git-update-index --remove -- %s' % path)
        # file deleted in one and changed in the other
        else:
            # Do something here - we must at least merge the entry in
            # the cache, instead of leaving it in U(nmerged) state. In
            # fact, stg resolved does not handle that.

            # Do the same thing cogito does - remove the file in any case.
            os.system('git-update-index --remove -- %s' % path)

            #if file1_hash:
                ## file deleted upstream and changed in the patch. The
                ## patch is probably going to move the changes
                ## elsewhere.

                #os.system('git-update-index --remove -- %s' % path)
            #else:
                ## file deleted in the patch and changed upstream. We
                ## could re-delete it, but for now leave it there -
                ## and let the user check if he still wants to remove
                ## the file.

                ## reset the cache to the first branch
                #os.system('git-update-index --cacheinfo %s %s %s'
                #          % (file1_mode, file1_hash, path))
            __conflict(path)
            return 1

    # file does not exist in origin
    else:
        # file added in both
        if file1_hash and file2_hash:
            # files are the same
            if file1_hash == file2_hash:
                if os.system('git-update-index --add --cacheinfo %s %s %s'
                             % (file1_mode, file1_hash, path)) != 0:
                    print >> sys.stderr, 'Error: git-update-index failed'
                    __conflict(path)
                    return 1
                if os.system('git-checkout-index -u -f -- %s' % path):
                    print >> sys.stderr, 'Error: git-checkout-index failed'
                    __conflict(path)
                    return 1
                if file1_mode != file2_mode:
                    print >> sys.stderr, \
                          'Error: File "s" added in both, ' \
                          'permissions conflict' % path
                    __conflict(path)
                    return 1
            # files are different
            else:
                # reset the index to the current file
                os.system('git-update-index -- %s' % path)
                print >> sys.stderr, \
                      'Error: File "%s" added in branches but different' % path
                __conflict(path)
                return 1
        # file added in one
        elif file1_hash or file2_hash:
            if file1_hash:
                mode = file1_mode
                obj = file1_hash
            else:
                mode = file2_mode
                obj = file2_hash
            if os.system('git-update-index --add --cacheinfo %s %s %s'
                         % (mode, obj, path)) != 0:
                print >> sys.stderr, 'Error: git-update-index failed'
                __conflict(path)
                return 1
            __remove_files(orig_hash, file1_hash, file2_hash)
            return os.system('git-checkout-index -u -f -- %s' % path)

    # Unhandled case
    print >> sys.stderr, 'Error: Unhandled merge conflict: ' \
          '"%s" "%s" "%s" "%s" "%s" "%s" "%s"' \
          % (orig_hash, file1_hash, file2_hash,
             path,
             orig_mode, file1_mode, file2_mode)
    __conflict(path)
    return 1
Commit	Line	Data
3659ef88 CM	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
170f576b	22	from stgit import basedir
f7ed76a9	23	from stgit.config import config, file_extensions, ConfigOption
3659ef88 CM	24	from stgit.utils import append_string
	25
	26
	27	class GitMergeException(Exception):
	28	pass
	29
	30
	31	#
	32	# Options
	33	#
eee7283e CM	34	merger = ConfigOption('stgit', 'merger')
eee7283e CM	35	keeporig = ConfigOption('stgit', 'keeporig')
3659ef88 CM	36
	37	#
	38	# Utility functions
	39	#
	40	def __str2none(x):
	41	if x == '':
	42	return None
	43	else:
	44	return x
	45
	46	def __output(cmd):
	47	f = os.popen(cmd, 'r')
	48	string = f.readline().rstrip()
	49	if f.close():
	50	raise GitMergeException, 'Error: failed to execute "%s"' % cmd
	51	return string
	52
	53	def __checkout_files(orig_hash, file1_hash, file2_hash,
	54	path,
	55	orig_mode, file1_mode, file2_mode):
	56	"""Check out the files passed as arguments
	57	"""
	58	global orig, src1, src2
	59
1e075406 CM	60	extensions = file_extensions()
1e075406 CM	61
3659ef88	62	if orig_hash:
1e075406	63	orig = path + extensions['ancestor']
3659ef88 CM	64	tmp = __output('git-unpack-file %s' % orig_hash)
	65	os.chmod(tmp, int(orig_mode, 8))
	66	os.renames(tmp, orig)
	67	if file1_hash:
1e075406	68	src1 = path + extensions['current']
3659ef88 CM	69	tmp = __output('git-unpack-file %s' % file1_hash)
	70	os.chmod(tmp, int(file1_mode, 8))
	71	os.renames(tmp, src1)
	72	if file2_hash:
1e075406	73	src2 = path + extensions['patched']
3659ef88 CM	74	tmp = __output('git-unpack-file %s' % file2_hash)
	75	os.chmod(tmp, int(file2_mode, 8))
	76	os.renames(tmp, src2)
	77
8d415553 CM	78	if file1_hash and not os.path.exists(path):
	79	# the current file might be removed by GIT when it is a new
	80	# file added in both branches. Just re-generate it
	81	tmp = __output('git-unpack-file %s' % file1_hash)
	82	os.chmod(tmp, int(file1_mode, 8))
	83	os.renames(tmp, path)
	84
3659ef88 CM	85	def __remove_files(orig_hash, file1_hash, file2_hash):
	86	"""Remove any temporary files
	87	"""
	88	if orig_hash:
	89	os.remove(orig)
	90	if file1_hash:
	91	os.remove(src1)
	92	if file2_hash:
	93	os.remove(src2)
3659ef88	94
3659ef88 CM	95	def __conflict(path):
	96	"""Write the conflict file for the 'path' variable and exit
	97	"""
170f576b	98	append_string(os.path.join(basedir.get(), 'conflicts'), path)
3659ef88 CM	99
3659ef88 CM	100
f7ed76a9 CM	101	def interactive_merge(filename):
	102	"""Run the interactive merger on the given file. Note that the
	103	index should not have any conflicts.
	104	"""
c73e63b7 YD	105	imerger = config.get('stgit.imerger')
c73e63b7 YD	106	if not imerger:
f7ed76a9 CM	107	raise GitMergeException, 'Configuration error: %s' % err
	108
	109	extensions = file_extensions()
	110
	111	ancestor = filename + extensions['ancestor']
	112	current = filename + extensions['current']
	113	patched = filename + extensions['patched']
	114
	115	# check whether we have all the files for a three-way merge
	116	for fn in [filename, ancestor, current, patched]:
	117	if not os.path.isfile(fn):
	118	raise GitMergeException, \
	119	'Cannot run the interactive merger: "%s" missing' % fn
	120
	121	mtime = os.path.getmtime(filename)
	122
	123	err = os.system(imerger % {'branch1': current,
	124	'ancestor': ancestor,
	125	'branch2': patched,
	126	'output': filename})
	127
	128	if err != 0:
	129	raise GitMergeException, 'The interactive merge failed: %d' % err
	130	if not os.path.isfile(filename):
	131	raise GitMergeException, 'The "%s" file is missing' % filename
	132	if mtime == os.path.getmtime(filename):
	133	raise GitMergeException, 'The "%s" file was not modified' % filename
	134
	135
3659ef88 CM	136	#
	137	# Main algorithm
	138	#
	139	def merge(orig_hash, file1_hash, file2_hash,
	140	path,
	141	orig_mode, file1_mode, file2_mode):
	142	"""Three-way merge for one file algorithm
	143	"""
	144	__checkout_files(orig_hash, file1_hash, file2_hash,
	145	path,
	146	orig_mode, file1_mode, file2_mode)
	147
	148	# file exists in origin
	149	if orig_hash:
	150	# modified in both
	151	if file1_hash and file2_hash:
	152	# if modes are the same (git-read-tree probably dealt with it)
	153	if file1_hash == file2_hash:
	154	if os.system('git-update-index --cacheinfo %s %s %s'
	155	% (file1_mode, file1_hash, path)) != 0:
	156	print >> sys.stderr, 'Error: git-update-index failed'
	157	__conflict(path)
	158	return 1
	159	if os.system('git-checkout-index -u -f -- %s' % path):
	160	print >> sys.stderr, 'Error: git-checkout-index failed'
	161	__conflict(path)
	162	return 1
	163	if file1_mode != file2_mode:
	164	print >> sys.stderr, \
	165	'Error: File added in both, permissions conflict'
	166	__conflict(path)
	167	return 1
	168	# 3-way merge
	169	else:
5b99888b CM	170	merge_ok = os.system(str(merger) % {'branch1': src1,
	171	'ancestor': orig,
	172	'branch2': src2,
	173	'output': path }) == 0
3659ef88 CM	174
	175	if merge_ok:
	176	os.system('git-update-index -- %s' % path)
	177	__remove_files(orig_hash, file1_hash, file2_hash)
	178	return 0
	179	else:
	180	print >> sys.stderr, \
	181	'Error: three-way merge tool failed for file "%s"' \
	182	% path
	183	# reset the cache to the first branch
	184	os.system('git-update-index --cacheinfo %s %s %s'
	185	% (file1_mode, file1_hash, path))
f7ed76a9	186
c73e63b7	187	if config.get('stgit.autoimerge') == 'yes':
f7ed76a9 CM	188	print >> sys.stderr, \
	189	'Trying the interactive merge'
	190	try:
	191	interactive_merge(path)
	192	except GitMergeException, ex:
	193	# interactive merge failed
	194	print >> sys.stderr, str(ex)
	195	if str(keeporig) != 'yes':
	196	__remove_files(orig_hash, file1_hash,
	197	file2_hash)
	198	__conflict(path)
	199	return 1
	200	# successful interactive merge
0f4eba6a	201	os.system('git-update-index -- %s' % path)
3659ef88	202	__remove_files(orig_hash, file1_hash, file2_hash)
f7ed76a9 CM	203	return 0
	204	else:
	205	# no interactive merge, just mark it as conflict
	206	if str(keeporig) != 'yes':
	207	__remove_files(orig_hash, file1_hash, file2_hash)
	208	__conflict(path)
	209	return 1
	210
3659ef88 CM	211	# file deleted in both or deleted in one and unchanged in the other
	212	elif not (file1_hash or file2_hash) \
	213	or file1_hash == orig_hash or file2_hash == orig_hash:
	214	if os.path.exists(path):
	215	os.remove(path)
	216	__remove_files(orig_hash, file1_hash, file2_hash)
	217	return os.system('git-update-index --remove -- %s' % path)
	218	# file deleted in one and changed in the other
	219	else:
	220	# Do something here - we must at least merge the entry in
	221	# the cache, instead of leaving it in U(nmerged) state. In
	222	# fact, stg resolved does not handle that.
	223
	224	# Do the same thing cogito does - remove the file in any case.
	225	os.system('git-update-index --remove -- %s' % path)
	226
	227	#if file1_hash:
	228	## file deleted upstream and changed in the patch. The
	229	## patch is probably going to move the changes
	230	## elsewhere.
	231
	232	#os.system('git-update-index --remove -- %s' % path)
	233	#else:
	234	## file deleted in the patch and changed upstream. We
	235	## could re-delete it, but for now leave it there -
	236	## and let the user check if he still wants to remove
	237	## the file.
	238
	239	## reset the cache to the first branch
	240	#os.system('git-update-index --cacheinfo %s %s %s'
	241	# % (file1_mode, file1_hash, path))
	242	__conflict(path)
	243	return 1
	244
	245	# file does not exist in origin
	246	else:
	247	# file added in both
	248	if file1_hash and file2_hash:
	249	# files are the same
	250	if file1_hash == file2_hash:
	251	if os.system('git-update-index --add --cacheinfo %s %s %s'
	252	% (file1_mode, file1_hash, path)) != 0:
	253	print >> sys.stderr, 'Error: git-update-index failed'
	254	__conflict(path)
	255	return 1
	256	if os.system('git-checkout-index -u -f -- %s' % path):
	257	print >> sys.stderr, 'Error: git-checkout-index failed'
	258	__conflict(path)
	259	return 1
	260	if file1_mode != file2_mode:
	261	print >> sys.stderr, \
	262	'Error: File "s" added in both, ' \
	263	'permissions conflict' % path
	264	__conflict(path)
	265	return 1
	266	# files are different
	267	else:
56df21ed CM	268	# reset the index to the current file
56df21ed CM	269	os.system('git-update-index -- %s' % path)
3659ef88 CM	270	print >> sys.stderr, \
	271	'Error: File "%s" added in branches but different' % path
	272	__conflict(path)
	273	return 1
	274	# file added in one
	275	elif file1_hash or file2_hash:
	276	if file1_hash:
	277	mode = file1_mode
	278	obj = file1_hash
	279	else:
	280	mode = file2_mode
	281	obj = file2_hash
	282	if os.system('git-update-index --add --cacheinfo %s %s %s'
	283	% (mode, obj, path)) != 0:
	284	print >> sys.stderr, 'Error: git-update-index failed'
	285	__conflict(path)
	286	return 1
	287	__remove_files(orig_hash, file1_hash, file2_hash)
	288	return os.system('git-checkout-index -u -f -- %s' % path)
	289
	290	# Unhandled case
	291	print >> sys.stderr, 'Error: Unhandled merge conflict: ' \
	292	'"%s" "%s" "%s" "%s" "%s" "%s" "%s"' \
	293	% (orig_hash, file1_hash, file2_hash,
	294	path,
	295	orig_mode, file1_mode, file2_mode)
	296	__conflict(path)
	297	return 1