mercurial/util.py
author maf46@burn.cl.cam.ac.uk
Mon, 04 Jul 2005 12:38:34 -0800
changeset 616 d45d1c90032e
parent 556 f6c6fa15ff70
child 667 31a9aa890016
permissions -rw-r--r--
Fix zombie files in merge # HG changeset patch # User maf46@burn.cl.cam.ac.uk # Node ID 57667c9b93a5a743e4629d15a0e6bd76699130c3 # Parent d2994b5298fb20f87dc1d4747635b280db3c0526 Fix zombie files in merge Keir Fraser observed the following: > I made a small test case that illustrates the bug in merging changesets > with 'hg remove's in them: > > 1. Create a repository A containing files foo & bar. > 2. Create clone called B. > 3. A removes file bar, and commits this removal. > 4. B edits file foo, and commits this edit. > > Now, if B: > # hg pull ../A; hg update -m; hg commit > Then bar remains deleted. > > If A: > # hg pull ../B; hg update -m; hg commit > Then bar is resurrected! > > It looks as though, when you merge across a branch, any deletions in > your own branch are forgotten. > ... > Fixing this is a must, as zombie files are a real pain. :-) Keir later patched our local copy of hg as shown below, which fixes the problem. I've also enclosed a test which captures the test Keir outlined... Files deleted on a branch should not automatically reappear in a merge Patch notes: 1. The first chunk does not change behaviour, but cleans up the code to more closely match check of 'force' in the second chunk. I think it makes the code clearer. 2. The second chunk fixes two bugs -- i. If we choose to keep a remotely-changed locally-deleted file, then we need to 'get' that file. If we choose to delete it then no action need be taken (it is already deleted in the working manifest). Without this fix, choosing to delete would get a Python traceback. ii. The test for whether the file was remotely-created is insufficient. It is only true if f is not in the common ancestor. Otherwise the file was deleted locally, and should remain deleted. (this is the most important fix!) Index: hg/tests/test-merge6 ===================================================================

# util.py - utility functions and platform specfic implementations
#
# Copyright 2005 K. Thananchayan <thananck@yahoo.com>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

import os

def unique(g):
    seen = {}
    for f in g:
        if f not in seen:
            seen[f] = 1
            yield f

class CommandError(Exception): pass

def explain_exit(code):
    """return a 2-tuple (desc, code) describing a process's status"""
    if os.WIFEXITED(code):
        val = os.WEXITSTATUS(code)
        return "exited with status %d" % val, val
    elif os.WIFSIGNALED(code):
        val = os.WTERMSIG(code)
        return "killed by signal %d" % val, val
    elif os.WIFSTOPPED(code):
        val = os.STOPSIG(code)
        return "stopped by signal %d" % val, val
    raise ValueError("invalid exit code")

def system(cmd, errprefix=None):
    """execute a shell command that must succeed"""
    rc = os.system(cmd)
    if rc:
        errmsg = "%s %s" % (os.path.basename(cmd.split(None, 1)[0]),
                            explain_exit(rc)[0])
        if errprefix:
            errmsg = "%s: %s" % (errprefix, errmsg)
        raise CommandError(errmsg)

def rename(src, dst):
    try:
        os.rename(src, dst)
    except:
        os.unlink(dst)
        os.rename(src, dst)

# Platfor specific varients
if os.name == 'nt':
    nulldev = 'NUL:'

    def is_exec(f, last):
        return last

    def set_exec(f, mode):
        pass

    def pconvert(path):
        return path.replace("\\", "/")

    def makelock(info, pathname):
        ld = os.open(pathname, os.O_CREAT | os.O_WRONLY | os.O_EXCL)
        os.write(ld, info)
        os.close(ld)

    def readlock(pathname):
        return file(pathname).read()

else:
    nulldev = '/dev/null'

    def is_exec(f, last):
        return (os.stat(f).st_mode & 0100 != 0)

    def set_exec(f, mode):
        s = os.stat(f).st_mode
        if (s & 0100 != 0) == mode:
            return
        if mode:
            # Turn on +x for every +r bit when making a file executable
            # and obey umask.
            umask = os.umask(0)
            os.umask(umask)
            os.chmod(f, s | (s & 0444) >> 2 & ~umask)
        else:
            os.chmod(f, s & 0666)

    def pconvert(path):
        return path

    def makelock(info, pathname):
        os.symlink(info, pathname)

    def readlock(pathname):
        return os.readlink(pathname)