git - git 和 append-moSTLy 文件的策略

Question

我的存储库中有一些文件在底部增长:大部分更改涉及在文件底部添加新行。这主要是语言和其他属性文件。

作为一个恼人的副作用，每当两个人同时进行添加时，我都会遇到 merge 冲突，并且解决方案总是涉及手动复制粘贴，以便包含两个版本的行。

是否有提示、技巧或方法可以减轻此过程的一些痛苦？

例如，一个简单的解决方案是告诉开发人员在文件中间的随机位置添加新行。这可能会奏效，但它需要有意识的努力和一段看起来很奇怪的历史。

Answer 1

您可以使用 gitattributes定义自定义 merge 驱动程序(如 this one for instance)以便自动复制相关部分的机制。

[merge "aggregate"]
        name = agregate both new sections
        driver = aggregate.sh %O %A %B

这将是一个 3 向 merge ，这意味着您可以轻松地将 %A 和 %B 与 %O(共同祖先) 以便隔离所述新部分，并将它们聚合到结果 merge 文件中。

聚合 merge 驱动程序只需要做:

comm -13 $1 $3 >> $2

(comm 实用程序是 GoW -- Gnu on Windows 的一部分——分发版，如果您使用的是 Windows)

---

这是一个小演示:

首先，让我们设置一个 Git 存储库，在两个分支('master' 和 'abranch')中修改一个文件:

C:\prog\git\tests>mkdir agg
C:\prog\git\tests>cd agg
C:\prog\git\tests\agg>git init r1
Initialized empty Git repository in C:/prog/git/tests/agg/r1/.git/
C:\prog\git\tests\agg>cd r1

# Who am I?
C:\prog\git\tests\agg\r1>git config user.name VonC
C:\prog\git\tests\agg\r1>git config user.email vonc@xxx

# one file, first commit:
C:\prog\git\tests\agg\r1>echo test > test.txt
C:\prog\git\tests\agg\r1>git add .
C:\prog\git\tests\agg\r1>git commit -m "first commit"
[master c34668d] first commit
 1 file changed, 1 insertion(+)
 create mode 100644 test.txt

# Let's add one more common line:
C:\prog\git\tests\agg\r1>echo base >> test.txt
C:\prog\git\tests\agg\r1>more test.txt
test
base
C:\prog\git\tests\agg\r1>git add .
C:\prog\git\tests\agg\r1>git commit -m "base"
[master d1cde8d] base
 1 file changed, 1 insertion(+)

现在我们创建一个新分支，并在该文件的两个版本中进行并发修改，在它的末尾，如 OP itsadok在问题中指定。

C:\prog\git\tests\agg\r1>git checkout -b abranch
Switched to a new branch 'abranch'
C:\prog\git\tests\agg\r1>echo "modif from abranch" >> test.txt
C:\prog\git\tests\agg\r1>git add .
C:\prog\git\tests\agg\r1>git commit -m "abranch contrib"
[abranch a4d2632] abranch contrib
 1 file changed, 1 insertion(+)
C:\prog\git\tests\agg\r1>type test.txt
test
base
"modif from abranch"

# back to master
C:\prog\git\tests\agg\r1>git checkout master
Switched to branch 'master'
C:\prog\git\tests\agg\r1>echo "contrib from master" >> test.txt
C:\prog\git\tests\agg\r1>git add .
C:\prog\git\tests\agg\r1>git commit -m "contrib from master"
[master 45bec4d] contrib from master
 1 file changed, 1 insertion(+)
C:\prog\git\tests\agg\r1>type test.txt
test
base
"contrib from master"

我们有两个分支(注:git lg is an alias of mine)

C:\prog\git\tests\agg\r1>git lg
* 45bec4d - (HEAD, master) contrib from master (86 minutes ago) VonC
| * a4d2632 - (abranch) abranch contrib (86 minutes ago) VonC
|/
* d1cde8d - base (87 minutes ago) VonC
* c34668d - first commit (89 minutes ago) VonC

现在让我们尝试 merge :

C:\prog\git\tests\agg\r1>git merge abranch
Auto-merging test.txt
CONFLICT (content): Merge conflict in test.txt
Automatic merge failed; fix conflicts and then commit the result.

C:\prog\git\tests\agg\r1>more test.txt
test
base
<<<<<<< HEAD
"contrib from master"
=======
"modif from abranch"
>>>>>>> abranch

...如所宣传的那样失败 ;) git merge --abort 将重置情况。

让我们放置 merge 驱动程序:

C:\prog\git\tests\agg\r1>git config merge.aggregate.name "aggregate both new sections"
C:\prog\git\tests\agg\r1>git config merge.aggregate.driver "aggregate.sh %O %A %B"
C:\prog\git\tests\agg\r1>echo test.txt merge=aggregate > .gitattributes

此时 merge 还是失败了:

C:\prog\git\tests\agg\r1>git merge abranch
aggregate.sh .merge_file_a09308 .merge_file_b09308 .merge_file_c09308: aggregate.sh: command not found
fatal: Failed to execute internal merge

正常:我们需要编写该脚本，并将其添加到PATH:

vim aggregate.sh:
#!/bin/bash

# echo O: $1
# echo A: $2
# echo B: $3

# After http://serverfault.com/q/68684/783
# How can I get diff to show only added and deleted lines?
# On Windows, install GoW (https://github.com/bmatzelle/gow/wiki/)
ob=$(comm -13 $1 $3)
# echo "ob: ${ob}"

echo ${ob} >> $2

----

C:\prog\git\tests\agg\r1>set PATH=%PATH%;C:\prog\git\tests\agg\r1

现在，aggregate merge 驱动程序可以运行:

C:\prog\git\tests\agg\r1>git merge --no-commit abranch
Auto-merging test.txt
Automatic merge went well; stopped before committing as requested

C:\prog\git\tests\agg\r1>type test.txt
test
base
"contrib from master"
"modif from abranch"

给你:abranch 的 test.txt 文件的末尾已添加到 master 上的文件中。