修复bug时，我们会通过创建新的bug分支进行修复，然后合并，最后删除；
当手头工作没有完成时，先把工作现场git stash一下，然后去修复bug，修复后，再git stash pop，回到工作现场。
当你接到一个修复一个代号101的bug的任务时，很自然地，你想创建一个分支issue-101来修复它，但是，等等，当前正在dev上进行的工作还没有提交：
$ git status
On branch dev
Changes to be committed:
(use "git reset HEAD <file>..." to unstage)
new file: hello.py
Changes not staged for commit:
(use "git add <file>..." to update what will be committed)
(use "git checkout -- <file>..." to discard changes in working directory)
modified: readme.txt
并不是你不想提交，而是工作只进行到一半，还没法提交，预计完成还需1天时间。但是，必须在两个小时内修复该bug，怎么办？
幸好，Git还提供了一个stash功能，可以把当前工作分支“储藏”起来，等以后恢复现场后继续工作：
$ git stash
Saved working directory and index state WIP on dev: f52c633 add merge
在master上加入新分支修复bug：
$ git checkout master
Switched to branch 'master'
Your branch is ahead of 'origin/master' by 6 commits.
(use "git push" to publish your local commits)
$ git checkout -b issue-101
Switched to a new branch 'issue-101'
bug修复后提交：
$ git add readme.txt
$ git commit -m "fix bug 101"
[issue-101 4c805e2] fix bug 101
1 file changed, 1 insertion(+), 1 deletion(-)
切换到master分支，并完成合并，最后删除issue-101分支：
$ git checkout master
Switched to branch 'master'
Your branch is ahead of 'origin/master' by 6 commits.
(use "git push" to publish your local commits)
$ git merge --no-ff -m "merged bug fix 101" issue-101
Merge made by the 'recursive' strategy.
readme.txt | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
现在，是时候接着回到dev分支干活了！
$ git checkout dev
Switched to branch 'dev'
$ git status
On branch dev
nothing to commit, working tree clean
工作区是干净的，刚才的工作现场存到哪去了？用git stash list命令看看：
$ git stash list
stash@{0}: WIP on dev: f52c633 add merge
工作现场还在，Git把stash内容存在某个地方了，但是需要恢复一下，有两个办法：
一是用git stash apply恢复，但是恢复后，stash内容并不删除，你需要用git stash drop来删除；
另一种方式是用git stash pop，恢复的同时把stash内容也删了：
$ git stash pop
On branch dev
Changes to be committed:
(use "git reset HEAD <file>..." to unstage)
new file: hello.py
Changes not staged for commit:
(use "git add <file>..." to update what will be committed)
(use "git checkout -- <file>..." to discard changes in working directory)
modified: readme.txt
Dropped refs/stash@{0} (5d677e2ee266f39ea296182fb2354265b91b3b2a)
