使用大括号引用git修订/引用失败 [英] Using curly braces referencing git revisions/references fails

问题描述

  git checkout stash @ {0}  -  some / file 
  

这会导致致命：invalid reference：stash @ 0

看起来大括号已被消除，但我不确定这个罪魁祸首。

存储版本在那里。 git存储清单退货

 存储@ {0}：WIP on X 
 stash @ {1}：WIP on Y 
  

我使用git 1.9.1 zsh。

有没有一种方法可以防止消除大括号？

解决方案

<引用包含 {...} 序列的字符串通常更好（例如， git checkout'stash @ {0}'）。 。），因为它们需要大括号扩展。
（或者，就此而言，单引号任何要保留的字符串字面值 ）。但是，在 默认 zsh 环境中， > 不成为问题，因为 {0} 不是有效的大括号表达式因此只需按原样打印（同样适用于 bash ， dash 和 ksh ）;验证：

  echo stash @ {0}＃在bash，dash，ksh，zsh中按原样打印（默认选项为效果）
  

赞美 chepner 因怀疑 BRACE_CLL zsh 选项可能被设置为，这确实产生了这样的症状：

  $ setopt BRACE_CCL 
 $ echo stash @ {0} 
 stash @ 0＃!!大括号删除
  

正如chepner所述， BRACE_CCL 导致 {0} 被视为包含一个字符的字符类，而不是逐字处理。换句话说： BRACE_CCL 展开 {...} 中的每个单独字符 ， echo一个{01} - > a0 a1 ），并且仅指定一个字符，净效果是去除封闭的大括号。

由于OP自己确认， unsetopt BRACE_CCL 解决了这个问题。

I am trying to checkout a single file from stash:

git checkout stash@{0} -- some/file

This fails with fatal: invalid reference: stash@0

Looks like the curly braces are eliminated, but I am not sure about the culprit.

The stash revision is there. git stash list returns

stash@{0}: WIP on X
stash@{1}: WIP on Y

I am using git 1.9.1 on zsh.

Is there a way to prevent this brace elimination?

解决方案

It is generally better to quote strings that contain {...} sequences (e.g., git checkout 'stash@{0}' ...), because they are subject to brace expansion.
(Or, for that matter, single-quote any string literal you want to preserve as is.)

However, in a default zsh environment this would not be a problem, because {0} is not a valid brace expression and is therefore simply printed as is (equally applies to bash, dash, and ksh); verify with:

echo stash@{0}  # prints as is in bash, dash, ksh, zsh (with default options in effect)

Kudos to chepner for suspecting that the BRACE_CLL zsh option may be set, which indeed does produce the symptom:

$ setopt BRACE_CCL
$ echo stash@{0}
stash@0          # !! braces removed

As chepner states, BRACE_CCL "causes {0} to be treated as a character class containing one character, rather than being treated literally"; in other words: BRACE_CCL expands each individual character inside {...} (e.g., echo a{01} -> a0 a1) and with just one character specified, the net effect is removal of the enclosing braces.

As the OP himself has since confirmed, unsetopt BRACE_CCL solved the problem.

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