Alternatively, you can fix the symptoms directly by saving and restoring file timestamps. This is kinda ugly, but it was interesting to write.
Python Timestamp Save/Restore Script
#!/usr/bin/env python
from optparse import OptionParser
import os
import subprocess
import cPickle as pickle
try:
check_output = subprocess.check_output
except AttributeError:
# check_output was added in Python 2.7, so it's not always available
def check_output(*args, **kwargs):
kwargs['stdout'] = subprocess.PIPE
proc = subprocess.Popen(*args, **kwargs)
output = proc.stdout.read()
retcode = proc.wait()
if retcode != 0:
cmd = kwargs.get('args')
if cmd is None:
cmd = args[0]
err = subprocess.CalledProcessError(retcode, cmd)
err.output = output
raise err
else:
return output
def git_cmd(*args):
return check_output(['git'] + list(args), stderr=subprocess.STDOUT)
def walk_git_tree(rev):
""" Generates (sha1,path) pairs for all blobs (files) listed by git ls-tree. """
tree = git_cmd('ls-tree', '-r', '-z', rev).rstrip('\0')
for entry in tree.split('\0'):
print entry
mode, type, sha1, path = entry.split()
if type == 'blob':
yield (sha1, path)
else:
print 'WARNING: Tree contains a non-blob.'
def collect_timestamps(rev):
timestamps = {}
for sha1, path in walk_git_tree(rev):
s = os.lstat(path)
timestamps[path] = (sha1, s.st_mtime, s.st_atime)
print sha1, s.st_mtime, s.st_atime, path
return timestamps
def restore_timestamps(timestamps):
for path, v in timestamps.items():
if os.path.isfile(path):
sha1, mtime, atime = v
new_sha1 = git_cmd('hash-object', '--', path).strip()
if sha1 == new_sha1:
print 'Restoring', path
os.utime(path, (atime, mtime))
else:
print path, 'has changed (not restoring)'
elif os.path.exists(path):
print 'WARNING: File is no longer a file...'
def main():
oparse = OptionParser()
oparse.add_option('--save',
action='store_const', const='save', dest='action',
help='Save the timestamps of all git tracked files')
oparse.add_option('--restore',
action='store_const', const='restore', dest='action',
help='Restore the timestamps of git tracked files whose sha1 hashes have not changed')
oparse.add_option('--db',
action='store', dest='database',
help='Specify the path to the data file to restore/save from/to')
opts, args = oparse.parse_args()
if opts.action is None:
oparse.error('an action (--save or --restore) must be specified')
if opts.database is None:
repo = git_cmd('rev-parse', '--git-dir').strip()
dbpath = os.path.join(repo, 'TIMESTAMPS')
print 'Using default database:', dbpath
else:
dbpath = opts.database
rev = git_cmd('rev-parse', 'HEAD').strip()
print 'Working against rev', rev
if opts.action == 'save':
timestamps = collect_timestamps(rev)
data = (rev, timestamps)
pickle.dump(data, open(dbpath, 'wb'))
elif opts.action == 'restore':
rev, timestamps = pickle.load(open(dbpath, 'rb'))
restore_timestamps(timestamps)
if __name__ == '__main__':
main()
Bash Test Script
#!/bin/bash
if [ -d working ]; then
echo "Cowardly refusing to mangle an existing 'working' dir."
exit 1
fi
mkdir working
cd working
# create the repository/working copy
git init
# add a couple of files
echo "File added in master:r1." > file-1
echo "File added in master:r1." > file-2
mkdir dir
echo "File added in master:r1." > dir/file-3
git add file-1 file-2 dir/file-3
git commit -m "r1: add-1, add-2, add-3"
git tag r1
# sleep to ensure new or changed files won't have the same timestamp
echo "Listing at r1"
ls --full-time
sleep 5
# make a change
echo "File changed in master:r2." > file-2
echo "File changed in master:r2." > dir/file-3
echo "File added in master:r2." > file-4
git add file-2 dir/file-3 file-4
git commit -m "r2: change-2, change-3, add-4"
git tag r2
# sleep to ensure new or changed files won't have the same timestamp
echo "Listing at r2"
ls --full-time
sleep 5
# create a topic branch from r1 and make some changes
git checkout -b topic r1
echo "File changed in topic:r3." > file-2
echo "File changed in topic:r3." > dir/file-3
echo "File added in topic:r3." > file-5
git add file-2 dir/file-3 file-5
git commit -m "r3: change-2, change-3, add-5"
git tag r3
# sleep to ensure new or changed files won't have the same timestamp
echo "Listing at r3"
ls --full-time
sleep 5
echo "Saving timestamps"
../save-timestamps.py --save
echo "Checking out master and merging"
# merge branch 'topic'
git checkout master
git merge topic
echo "File changed in topic:r3." > file-2 # restore file-2
echo "File merged in master:r4." > dir/file-3
git add file-2 dir/file-3
git commit -m "r4: Merge branch 'topic'"
git tag r4
echo "Listing at r4"
ls --full-time
echo "Restoring timestamps"
../save-timestamps.py --restore
ls --full-time
I'll leave it as an exercise for the reader to clean up the Python script to remove extraneous output and add better error checking.
