在特定起点创建分支但保留相同的远程跟踪分支

Question

我想在HEAD创建一个新分支，保持与我当前所在分支相同的远程跟踪分支，然后查看新分支。这是我正在尝试使用的命令：

$ git checkout --track @{upstream} -b feature/cleanup-gradle HEAD
fatal: 'HEAD' is not a commit and a branch 'feature/cleanup-gradle' cannot be created from it

我不知道为什么我得到上面的错误。有没有办法让这项工作？

Answer 1

显然（基于错误），而不是任何现有的Git命令。不过，您当然可以编写自己的Git命令。将下面的脚本放在可执行的位置（我使用$HOME/scripts/进行此类操作），将其命名为git-nbranch，确保它是可执行的，然后运行git nbranch：

$ git nbranch
usage: git nbranch [options] newname

    Create new branch but set its upstream to the current branch's upstream.

    If and when this succeeds, you're on the new branch.

    -s, --start ...       starting commit for new branch (default HEAD)

该脚本说明了可用于编写Git命令的一些技术。

#! /bin/sh

OPTIONS_KEEPDASHDASH=
OPTIONS_STUCKLONG=
OPTIONS_SPEC="git nbranch [options] newname

Create new branch but set its upstream to the current branch's upstream.

If and when this succeeds, you're on the new branch.
--
s,start=  starting commit for new branch (default HEAD)
"

# parse options (defined above) and obtain "fatal" function etc.
. git-sh-setup

start=HEAD
while :; do
    case "$1" in
    --) shift; break;;
    -s) start="$2"; shift 2;;
    esac
done

case $# in 1) ;; *) usage; esac

# optional - we can just let git checkout -b check later
#ref=$(git check-ref-format --normalize "refs/heads/$1") ||
#    die "fatal: $1 is not a valid branch name"
#ref=${ref#refs/heads/} # make suitable for -b
ref="$1"

# compute settings
curbranch=$(git symbolic-ref -q --short HEAD) ||
    die "fatal: not on a branch"
case "$start" in
    HEAD) startrev=$(git rev-parse -q --verify HEAD) ||
    die "fatal: current branch does not exist yet";;
    *) startrev=$(git rev-parse -q --verify "$start"^{commit}) ||
    die "fatal: $start does not name an existing commit";;
esac
remote=$(git config --get branch.$curbranch.remote) ||
    die "fatal: current branch $curbranch has no remote"
merge=$(git config --get branch.$curbranch.merge) ||
    die "fatal: current branch $curbranch has no upstream"

git checkout -b "$ref" "$startrev" ||
    die "fatal: unable to create and switch to $ref"
git config branch."$ref".remote "$remote" &&
git config branch."$ref".merge "$merge"

Answer 2

只需关闭明确的HEAD：

$ git checkout --track @{u} -b new
Branch 'new' set up to track remote branch 'next' from 'origin'.
Switched to a new branch 'new'
$

git checkout没有指定提交或路径是一个无操作，除了选项效果，这是你想要的。也就是说，你得到的错误肯定会更好。

Answer 3

我创建了一个简单的别名来解决这个问题：

cob = "!f() { : git branch ; git checkout -b \"$@\" && git branch -u @{-1}@{upstream}; }; f"

用法（在跟踪master的origin/master上）：

$ git cob topic1

结果：

Switched to a new branch 'topic1'
Branch topic1 set up to track remote branch master from origin.