Question

我有以下情况：

* ab82147 (HEAD, topic) changes
* 8993636 changes
* 82f4426 changes
* 18be5a3 (master) first

我想将（非快进）topic合并到master。这需要我：

git checkout master
git merge --no-ff topic

但是检查master，然后将主题合并到它会导致git更改我的工作目录（虽然最终结果与检查master之前的结果相同），而我遇到的问题是由于我们的项目，它需要大约30分钟来构建它（使用IncrediBuild）虽然没有真正改变，但它简直无法忍受。

所以我想得到以下内容：

*   9075cf4 (HEAD, master) Merge branch 'topic'
|\  
| * ab82147 (topic) changes
| * 8993636 changes
| * 82f4426 changes
|/  
* 18be5a3 first

没有真正触及工作目录（或者至少在某种程度上欺骗git）。

Answer 1

有趣！我不认为有这样做的内置方法，但你应该能够使用管道来捏造它：

#!/bin/bash

branch=master
# or take an argument:
# if [ $@ eq 1 ];
#      branch="$1";
# fi

# make sure the branch exists
if ! git rev-parse --verify --quiet --heads "$branch" > /dev/null; then
     echo "error: branch $branch does not exist"
     exit 1
fi

# make sure this could be a fast-forward   
if [ "$(git merge-base HEAD $branch)" == "$(git rev-parse $branch)" ]; then
    # find the branch name associated with HEAD
    currentbranch=$(git symbolic-ref HEAD | sed 's@.*/@@')
    # make the commit
    newcommit=$(echo "Merge branch '$currentbranch'" | git commit-tree $(git log -n 1 --pretty=%T HEAD) -p $branch -p HEAD)
    # move the branch to point to the new commit
    git update-ref -m "merge $currentbranch: Merge made by simulated no-ff" "refs/heads/$branch" $newcommit
else
    echo "error: merging $currentbranch into $branch would not be a fast-forward"
    exit 1
fi

有趣的是newcommit=行;它使用commit-tree直接创建合并提交。第一个参数是要使用的树;那是树HEAD，你要保留其内容的分支。提交消息在stdin上提供，其余参数命名新提交应具有的父项。提交的SHA1打印到stdout，因此假设提交成功，您捕获它，然后合并该提交（这将是快进）。如果你很痴迷，你可以确保commit-tree成功 - 但这应该得到很好的保证。

限制：

这仅适用于可能快进的合并。显然，在这种情况下，您实际上必须签出并合并（可能在克隆中，以保存您的构建系统）。
reflog消息不同。我故意这样做，因为当你使用--no-ff时，git实际上会强迫自己使用默认（递归）策略，但是在reflog中写这个就是谎言。
如果您处于分离的HEAD模式，事情会变得很糟糕。那必须要特别对待。

是的，我在一个玩具回购中测试了它，它似乎正常工作！（虽然我没有努力打破它。）

Answer 2

我能想到的最简单的方法是git clone到一个单独的工作副本，在那里进行合并，然后再回到git pull。然后拉动将是快进，并且应该只影响真正改变的文件。

当然，有这么大的项目制作临时克隆并不理想，需要一大块额外的硬盘空间。只要您不需要磁盘空间，就可以通过保留合并副本来最小化（从长远来看）额外克隆的时间成本。

免责声明：我尚未证实这是有效的。我相信它应该（git不是版本文件时间戳）

Answer 3

或者，您可以通过保存和恢复文件时间戳来直接修复症状。这有点难看，但写作很有意思。

Python时间戳保存/恢复脚本

#!/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测试脚本

#!/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

我将把它作为练习让读者清理Python脚本以删除无关的输出并添加更好的错误检查。

Answer 4

这是一种作弊版本。

git stash
git tag tmptag
git merge --no-ff topic
git checkout tmptag（-b tha_brunch）？
git stash pop
git tag -D tmptag

Answer 5

将母版合并到主题：git将原件/母版合并或将主题合并到自身
更改母版的负责人：git update-ref refs / heads / master refs / heads / topic

您现在可以返回主题进行预合并提交：git reset HEAD〜

Answer 6

绝对可以进行任何合并，甚至是非快进合并，而无需$scope.switchView = function(){ // I want to cfset session.remoteuser = userid // and redirect to main page to change the view }，弄乱提交历史记录或克隆。秘诀是添加第二个“工作树”，这样您就可以在同一存储库中有效地进行主要和次要结帐。

git checkout

您现在已将本地工作分支合并到本地cd local_repo git worktree add _master_wt master cd _master_wt git pull origin master:master git merge --no-ff -m "merging workbranch" my_work_branch cd .. git worktree remove _master_wt分支，而无需切换结帐。

合并而不更改工作目录

6 个答案: