06 分支管理 —— Bug分支

06 分支管理 —— Bug分支

軟件開發中，bug就像屢見不鮮同樣。有了bug就須要修復，在Git中，因爲分支是如此的強大，因此每一個bug均可以經過一個新的臨時分支來修復，修復後，合併分支，而後將臨時分支刪除。

切換回dev分支

lwenhaodeMacBook-Pro:TestGit lwenhao$ git checkout dev
Switched to branch 'dev'

修改README.md內容：

lwenhaodeMacBook-Pro:TestGit lwenhao$ cat README.md 
# TestGit

建立一個"dev"分支，我來操做。

學習分支管理策略。

編輯了dev分支上的內容，如今準備學習bug分支

lwenhaodeMacBook-Pro:TestGit lwenhao$

當你找到一個openfire的bug的任務時，你想建立一個分支issue-openfire來修復它，可是，當前正在dev上進行的工做尚未提交：

lwenhaodeMacBook-Pro:TestGit lwenhao$ git status
On branch dev
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.md

no changes added to commit (use "git add" and/or "git commit -a")
lwenhaodeMacBook-Pro:TestGit lwenhao$

並非你不想提交，而是工做只進行到一半，還無法提交，預計完成還需1天時間。可是，必須在兩個小時內修復該bug，怎麼辦？

幸虧，Git還提供了一個stash功能，能夠把當前工做現場「儲藏」起來，等之後恢復現場後繼續工做：

lwenhaodeMacBook-Pro:TestGit lwenhao$ git stash
Saved working directory and index state WIP on dev: 8faa495 add 學習
lwenhaodeMacBook-Pro:TestGit lwenhao$

如今，用git status查看工做區，就是乾淨的，所以能夠放心地建立分支來修復bug。

lwenhaodeMacBook-Pro:TestGit lwenhao$ git status
On branch dev
nothing to commit, working tree clean
lwenhaodeMacBook-Pro:TestGit lwenhao$

首先肯定要在哪一個分支上修復bug，假定須要在master分支上修復，就從master建立臨時分支：

lwenhaodeMacBook-Pro:TestGit lwenhao$ 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)
lwenhaodeMacBook-Pro:TestGit lwenhao$ git checkout -b issue-openfire
Switched to a new branch 'issue-openfire'
lwenhaodeMacBook-Pro:TestGit lwenhao$

如今修復bug，須要把README.md中的「dev」改成「master」

lwenhaodeMacBook-Pro:TestGit lwenhao$ cat README.md 
# TestGit

建立一個"master"分支，我來操做。

學習分支管理策略。

lwenhaodeMacBook-Pro:TestGit lwenhao$

而後提交：

lwenhaodeMacBook-Pro:TestGit lwenhao$ git add README.md 
lwenhaodeMacBook-Pro:TestGit lwenhao$ git commit -m "dev to master"
[issue-openfire c0e8f25] dev to master
 1 file changed, 1 insertion(+), 1 deletion(-)
lwenhaodeMacBook-Pro:TestGit lwenhao$

修復完成後，切換到master分支，並完成合並，最後刪除issue-openfire分支：

lwenhaodeMacBook-Pro:TestGit lwenhao$ 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)
lwenhaodeMacBook-Pro:TestGit lwenhao$ git merge --no-ff -m "merged bug fix openfire" issue-openfire
Merge made by the 'recursive' strategy.
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
lwenhaodeMacBook-Pro:TestGit lwenhao$

原計劃兩個小時的bug修復只花了5分鐘！如今，是時候接着回到dev分支幹活了！

lwenhaodeMacBook-Pro:TestGit lwenhao$ git checkout dev
Switched to branch 'dev'
lwenhaodeMacBook-Pro:TestGit lwenhao$ git status
On branch dev
nothing to commit, working tree clean
lwenhaodeMacBook-Pro:TestGit lwenhao$

工做區是乾淨的，剛纔的工做現場存到哪去了？用git stash list命令看看：

lwenhaodeMacBook-Pro:TestGit lwenhao$ git stash list
stash@{0}: WIP on dev: 8faa495 add 學習
lwenhaodeMacBook-Pro:TestGit lwenhao$

工做現場還在，Git把stash內容存在某個地方了，可是須要恢復一下，有兩個辦法：

一是用git stash apply恢復，可是恢復後，stash內容並不刪除，你須要用git stash drop來刪除；

另外一種方式是用git stash pop，恢復的同時把stash內容也刪了：

lwenhaodeMacBook-Pro:TestGit lwenhao$ git stash pop
On branch dev
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.md

no changes added to commit (use "git add" and/or "git commit -a")
Dropped refs/stash@{0} (97050754b252007d69e787968cccfa46f54f7f31)
lwenhaodeMacBook-Pro:TestGit lwenhao$

再用git stash list查看，就看不到任何stash內容了：

lwenhaodeMacBook-Pro:TestGit lwenhao$ git stash list
lwenhaodeMacBook-Pro:TestGit lwenhao$

你能夠屢次stash，恢復的時候，先用git stash list查看，而後恢復指定的stash，用命令：

git stash apply stash@{0}

修復bug時，咱們會經過建立新的bug分支進行修復，而後合併，最後刪除；

當手頭工做沒有完成時，先把工做現場git stash一下，而後去修復bug，修復後，再git stash pop，回到工做現場。

繼續閱讀：07 分支管理 —— Feature分支