Git處理衝突

假設要在wchar_support分支中執行更改，修改wchar_support分支中的程式碼。新增一個計算長度的函式：count_len(obj)，程式碼變化如下 -

$ git branch
  master
* wchar_support

Administrator@MY-PC /D/worksp/sample/src (wchar_support)
$ git diff
diff --git a/src/string.py b/src/string.py
index ba6d584..4307fe2 100644
--- a/src/string.py
+++ b/src/string.py
@@ -13,4 +13,7 @@ a = '我'  #
 b = 'ab'
 ab = '我ab'

-print(len(a), len(b), len(ab), len('='))
\ No newline at end of file
+print(len(a), len(b), len(ab), len('='))
+
+def count_len(obj):
+    return len(obj)
\ No newline at end of file

假設驗證程式碼後，沒有問題就提交這些更改。

$ git status
On branch wchar_support
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:   string.py

no changes added to commit (use "git add" and/or "git commit -a")

Administrator@MY-PC /D/worksp/sample/src (wchar_support)
$ git add string.py

Administrator@MY-PC /D/worksp/sample/src (wchar_support)
$ git commit -m "add new function: count_len(obj)"
[wchar_support 1cc9ddb] add new function: count_len(obj)
 1 file changed, 4 insertions(+), 1 deletion(-)

執行 master 分支變更

同時在master分支中，另外一個開發人員(minsu)還會更改了內容，並將其更改推播到master分支。

yiibai@ubuntu:~/git/sample/src$ git diff
diff --git a/src/string.py b/src/string.py
index ba6d584..5eb2a5d 100644
--- a/src/string.py
+++ b/src/string.py
@@ -13,4 +13,6 @@ a = '我'  #
b = 'ab'
ab = '我ab'

-print(len(a), len(b), len(ab), len('='))
\ No newline at end of file
+print(len(a), len(b), len(ab), len('='))
+def obj_len(obj):
+    return len(obj)
yiibai@ubuntu:~/git/sample/src$

驗證差異後，現在就提交更新內容。

yiibai@ubuntu:~/git/sample/src$ git status
On branch master
Your branch is up-to-date with 'origin/master'.
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:   string.py

no changes added to commit (use "git add" and/or "git commit -a")
yiibai@ubuntu:~/git/sample/src$ git add string.py
yiibai@ubuntu:~/git/sample/src$ git commit -m 'Changed function name from w_strlen to my_wc_strlen'
[master 07cd5af] Changed function name from w_strlen to my_wc_strlen
 1 file changed, 3 insertions(+), 1 deletion(-)
yiibai@ubuntu:~/git/sample/src$ git push origin master
Username for 'http://git.oschina.net': [email protected]
Password for 'http://[email protected]@git.oschina.net':
Counting objects: 4, done.
Compressing objects: 100% (3/3), done.
Writing objects: 100% (4/4), 398 bytes | 0 bytes/s, done.
Total 4 (delta 1), reused 0 (delta 0)
To http://git.oschina.net/yiibai/sample.git
   e7d1734..07cd5af  master -> master

在wchar_support分支上，我們已經實現了一個count_len(obj)函式。假設經過測試後，提交並將其更改推播到wchar_support分支。

出現衝突

假設另外一個開發人員(minsu)想看看我們在wchar_branch分支上做了什麼，他試圖從wchar_support分支中拉出最新的變化，但是Git會中斷這個操作，並顯示以下錯誤訊息。

yiibai@ubuntu:~/git/sample/src$ git pull origin wchar_support
remote: Counting objects: 4, done.
remote: Compressing objects: 100% (3/3), done.
remote: Total 4 (delta 1), reused 0 (delta 0)
Unpacking objects: 100% (4/4), done.
From http://git.oschina.net/yiibai/sample
 * branch            wchar_support -> FETCH_HEAD
   e7d1734..1cc9ddb  wchar_support -> origin/wchar_support
Auto-merging src/string.py
CONFLICT (content): Merge conflict in src/string.py
Automatic merge failed; fix conflicts and then commit the result.
yiibai@ubuntu:~/git/sample/src$

解決衝突

從錯誤訊息中，很明顯檔案：src/string.py 中存在衝突。執行git diff命令檢視更多細節。

yiibai@ubuntu:~/git/sample/src$ git diff
diff --cc src/string.py
index 5eb2a5d,4307fe2..0000000
--- a/src/string.py
+++ b/src/string.py
@@@ -14,5 -14,6 +14,11 @@@ b = 'ab
  ab = '??‘ab'

  print(len(a), len(b), len(ab), len('='))
++<<<<<<< HEAD
 +def obj_len(obj):
 +    return len(obj)
++=======
+
+ def count_len(obj):
 -    return len(obj)
++    return len(obj)
++>>>>>>> 1cc9ddb410561976b006106590481cc01b79080e
yiibai@ubuntu:~/git/sample/src$

由於兩個人同進修改了string.py中的程式碼，所以Git處於混亂狀態，並且要求使用者手動解決衝突。

假設maxsu決定保留修改的程式碼，並刪除了自己定義的函式：obj_len(obj)。刪除衝突標記後(<<<<<<<<<<<<<<<< 和 >>>>>>>>>>>>>>>>>>>>的行)，現在衝突的程式碼如下所示 -

解決衝突需要修改程式碼後，如下所示 -

git diff將如下所示 -

yiibai@ubuntu:~/git/sample/src$ git diff
diff --cc src/string.py
index 5eb2a5d,4307fe2..0000000
--- a/src/string.py
+++ b/src/string.py
@@@ -14,5 -14,6 +14,7 @@@ b = 'ab
  ab = '??‘ab'

  print(len(a), len(b), len(ab), len('='))
+
 -def count_len(obj):
 -    return len(obj)
 +def obj_len(obj):
 +    return len(obj)
++
yiibai@ubuntu:~/git/sample/src$

由於minsu已經修改了這些檔案，所以必須首先提交這些修改，然後就可以提出這些修改。如下所示 -

yiibai@ubuntu:~/git/sample/src$ git add .
yiibai@ubuntu:~/git/sample/src$ git commit -a -m 'Resolved conflict'
[master 33f0406] Resolved conflict
yiibai@ubuntu:~/git/sample/src$ git pull origin wchar_support

已經解決了衝突，現在執行git pull應該沒有問題了。