comparison hgext/extdiff.py @ 9512:e7bde4680eec

extdiff: add 3-way diff for merge changesets

This adds 3-way diff for merge changesets (using -c) and for diffing
the working directory context against two parents. To enable it, use
the new magic value '$parent2' in the argument line. In order to work,
your differ must support that the second parent argument is left out;
this will happen in 2-way mode. Default arguments are as before, without
enabling 3-way mode, ensuring backwards compatibility.

This also fixes a problem when diffing a merge changeset with a single
file change. Extdiff would sometimes do the wrong thing in that situation.

9511:33033af09308

files, so running the external diff program will actually be pretty
fast (at least faster than having to compare the entire tree).
'''

from mercurial.i18n import _
from mercurial.node import short
from mercurial import cmdutil, util, commands
import os, shlex, shutil, tempfile

def snapshot(ui, repo, files, node, tmproot):
    '''snapshot files as of some revision
    if not using snapshot, -I/-X does not work and recursive diff
    in tools like kdiff3 and meld displays too many files.'''

    fns_and_mtime = []
    ctx = repo[node]
    for fn in files:
        wfn = util.pconvert(fn)
        if not wfn in ctx:
            # skipping new file after a merge ?
            continue
        ui.note('  %s\n' % wfn)
        dest = os.path.join(base, wfn)
        fctx = ctx[wfn]
        data = repo.wwritedata(wfn, fctx.data())

    - just invoke the diff for a single file in the working dir
    '''

    revs = opts.get('rev')
    change = opts.get('change')

    if revs and change:
        msg = _('cannot specify --rev and --change at the same time')
        raise util.Abort(msg)
    elif change:
        node2 = repo.lookup(change)
        node1 = repo[node2].parents()[0].node()
    else:
        node1, node2 = cmdutil.revpair(repo, revs)

    matcher = cmdutil.match(repo, pats, opts)
    modified, added, removed = repo.status(node1, node2, matcher)[:3]
    if not (modified or added or removed):
        return 0

    tmproot = tempfile.mkdtemp(prefix='extdiff.')
    dir2root = ''
    try:
        # Always make a copy of node1
        dir1 = snapshot(ui, repo, modified + removed, node1, tmproot)[0]
        changes = len(modified) + len(removed) + len(added)

        # If node2 in not the wc or there is >1 change, copy it
        if node2 or changes > 1:
            dir2, fns_and_mtime = snapshot(ui, repo, modified + added, node2, tmproot)
        else:
            # This lets the diff tool open the changed file directly
            dir2 = ''
            dir2root = repo.root
            fns_and_mtime = []

        # If only one change, diff the files instead of the directories
        if changes == 1 :
            if len(modified):
                dir1 = os.path.join(dir1, util.localpath(modified[0]))
                dir2 = os.path.join(dir2root, dir2, util.localpath(modified[0]))
            elif len(removed) :
                dir1 = os.path.join(dir1, util.localpath(removed[0]))
                dir2 = os.devnull
            else:
                dir1 = os.devnull
                dir2 = os.path.join(dir2root, dir2, util.localpath(added[0]))

        cmdline = ('%s %s %s %s' %
                   (util.shellquote(diffcmd), ' '.join(diffopts),
                    util.shellquote(dir1), util.shellquote(dir2)))
        ui.debug('running %r in %s\n' % (cmdline, tmproot))
        util.system(cmdline, cwd=tmproot)

        for copy_fn, working_fn, mtime in fns_and_mtime:
            if os.path.getmtime(copy_fn) != mtime:

9512:e7bde4680eec

files, so running the external diff program will actually be pretty
fast (at least faster than having to compare the entire tree).
'''

from mercurial.i18n import _
from mercurial.node import short, nullid
from mercurial import cmdutil, util, commands
import os, shlex, shutil, tempfile, re

def snapshot(ui, repo, files, node, tmproot):
    '''snapshot files as of some revision
    if not using snapshot, -I/-X does not work and recursive diff
    in tools like kdiff3 and meld displays too many files.'''

    fns_and_mtime = []
    ctx = repo[node]
    for fn in files:
        wfn = util.pconvert(fn)
        if not wfn in ctx:
            # File doesn't exist; could be a bogus modify
            continue
        ui.note('  %s\n' % wfn)
        dest = os.path.join(base, wfn)
        fctx = ctx[wfn]
        data = repo.wwritedata(wfn, fctx.data())

    - just invoke the diff for a single file in the working dir
    '''

    revs = opts.get('rev')
    change = opts.get('change')
    args = ' '.join(diffopts)
    do3way = '$parent2' in args

    if revs and change:
        msg = _('cannot specify --rev and --change at the same time')
        raise util.Abort(msg)
    elif change:
        node2 = repo.lookup(change)
        node1a, node1b = repo.changelog.parents(node2)
    else:
        node1a, node2 = cmdutil.revpair(repo, revs)
        if not revs:
            node1b = repo.dirstate.parents()[1]
        else:
            node1b = nullid

    # Disable 3-way merge if there is only one parent
    if do3way:
        if node1b == nullid:
            do3way = False

    matcher = cmdutil.match(repo, pats, opts)
    mod_a, add_a, rem_a = map(set, repo.status(node1a, node2, matcher)[:3])
    if do3way:
        mod_b, add_b, rem_b = map(set, repo.status(node1b, node2, matcher)[:3])
    else:
        mod_b, add_b, rem_b = set(), set(), set()
    modadd = mod_a | add_a | mod_b | add_b
    common = modadd | rem_a | rem_b
    if not common:
       return 0

    tmproot = tempfile.mkdtemp(prefix='extdiff.')
    try:
        # Always make a copy of node1a (and node1b, if applicable)
        dir1a_files = mod_a | rem_a | ((mod_b | add_b) - add_a)
        dir1a = snapshot(ui, repo, dir1a_files, node1a, tmproot)[0]
        if do3way:
            dir1b_files = mod_b | rem_b | ((mod_a | add_a) - add_b)
            dir1b = snapshot(ui, repo, dir1b_files, node1b, tmproot)[0]
        else:
            dir1b = None

        fns_and_mtime = []

        # If node2 in not the wc or there is >1 change, copy it
        dir2root = ''
        if node2:
            dir2 = snapshot(ui, repo, modadd, node2, tmproot)[0]
        elif len(common) > 1:
            #we only actually need to get the files to copy back to the working
            #dir in this case (because the other cases are: diffing 2 revisions
            #or single file -- in which case the file is already directly passed
            #to the diff tool).
            dir2, fns_and_mtime = snapshot(ui, repo, modadd, None, tmproot)
        else:
            # This lets the diff tool open the changed file directly
            dir2 = ''
            dir2root = repo.root

        # If only one change, diff the files instead of the directories
        # Handle bogus modifies correctly by checking if the files exist
        if len(common) == 1:
            common_file = util.localpath(common.pop())
            dir1a = os.path.join(dir1a, common_file)
            if not os.path.isfile(os.path.join(tmproot, dir1a)):
                dir1a = os.devnull
            if do3way:
                dir1b = os.path.join(dir1b, common_file)
                if not os.path.isfile(os.path.join(tmproot, dir1b)):
                    dir1b = os.devnull
            dir2 = os.path.join(dir2root, dir2, common_file)

        # Function to quote file/dir names in the argument string
        # When not operating in 3-way mode, an empty string is returned for parent2
        replace = dict(parent=dir1a, parent1=dir1a, parent2=dir1b, child=dir2)
        def quote(match):
            key = match.group()[1:]
            if not do3way and key == 'parent2':
                return ''
            return util.shellquote(replace[key])

        # Match parent2 first, so 'parent1?' will match both parent1 and parent
        regex = '\$(parent2|parent1?|child)'
        if not do3way and not re.search(regex, args):
            args += ' $parent1 $child'
        args = re.sub(regex, quote, args)
        cmdline = util.shellquote(diffcmd) + ' ' + args

        ui.debug('running %r in %s\n' % (cmdline, tmproot))
        util.system(cmdline, cwd=tmproot)

        for copy_fn, working_fn, mtime in fns_and_mtime:
            if os.path.getmtime(copy_fn) != mtime: