以编程方式显示合并期间使用的所有 git rerere 分辨率

Question

在启用 rerere 的情况下进行合并时，并且所有冲突都使用 rerere 解决，它只会打印如下内容：

Resolved 'a.c' using previous resolution.
Resolved 'b.c' using previous resolution.
Resolved 'c.c' using previous resolution.

我想看看之前的差异(带有冲突标记(和解决后的差异。我知道我能做到：

git checkout -m a.c
git diff
git rerere
git diff
git checkout -m b.c
git diff
git rerere
git diff
...

以查看它用于每种分辨率的前/后图像。但是有没有办法检索该信息或使用的 rerere 指纹，而无需手动解析每条Resolved X using previous resolution.消息的git merge hash输出。

Answer 1

感觉就像你想比较我们的，他们的和分辨率。从这里看来，git diff会拒绝比较 3 个文件。我已经修改了该帖子中的示例以提供此示例;

git diff --name-only master feature |
xargs -I % bash -c "diff3 <( git show master:% ) <( cat % ) <( git show feature:% )"

diff3 的输出更复杂，但这是您正在做的一件复杂的事情。

复制步骤

初始化存储库。

Horba@cake ~ $ git init MergeDiff/
Initialized empty Git repository in /home/Horba/MergeDiff/.git/
Horba@cake ~ $ cd MergeDiff/
Horba@cake ~/MergeDiff $ vim README.md
Horba@cake ~/MergeDiff $ git add README.md 
Horba@cake ~/MergeDiff $ git commit -m "Init."
[master (root-commit) 5250b3f] Init.
1 file changed, 3 insertions(+)
create mode 100644 README.md
Horba@cake ~/MergeDiff $ git branch feature
Horba@cake ~/MergeDiff $ git config rerere.enabled true
Horba@cake ~/MergeDiff $ git config rerere.autoupdate true
Horba@cake ~/MergeDiff $ vim README.md 
Horba@cake ~/MergeDiff $ git add README.md
Horba@cake ~/MergeDiff $ git commit -m "Work on master."
[master 8c12c43] Work on master.
1 file changed, 1 insertion(+), 1 deletion(-)
Horba@cake ~/MergeDiff $ git checkout feature
Switched to branch 'feature'
Horba@cake ~/MergeDiff $ vim README.md
Horba@cake ~/MergeDiff $ git commit -m "Work on feature."
[feature 4b8ad3d] Work on feature.
1 file changed, 1 insertion(+), 1 deletion(-)
Horba@cake ~/MergeDiff $ git checkout master
Switched to branch 'master'

执行初始合并。

Horba@cake ~/MergeDiff $ git merge feature 
Auto-merging README.md
CONFLICT (content): Merge conflict in README.md
Recorded preimage for 'README.md'
Automatic merge failed; fix conflicts and then commit the result.
Horba@cake ~/MergeDiff $ cat README.md
# MergeDiff
<<<<<<< HEAD
Init - master changes
=======
Init - Work on feature
>>>>>>> feature

存储分辨率。

Horba@cake ~/MergeDiff $ vim README.md
Horba@cake ~/MergeDiff $ git rerere
Recorded resolution for 'README.md'.
Horba@cake ~/MergeDiff $ cat README.md
# MergeDiff
Init - Resolved
Horba@cake ~/MergeDiff $ git merge --abort

使用 rerere.autoupdate 再次合并。

Horba@cake ~/MergeDiff $ git merge feature 
Auto-merging README.md
CONFLICT (content): Merge conflict in README.md
Staged 'README.md' using previous resolution.
Automatic merge failed; fix conflicts and then commit the result.
Horba@cake ~/MergeDiff $ cat README.md
# MergeDiff
Init - Resolved
Horba@cake ~/MergeDiff $ git status
On branch master
All conflicts fixed but you are still merging.
(use "git commit" to conclude merge)
Changes to be committed:
modified:   README.md

传统的差异无济于事。

Horba@cake ~/MergeDiff $ git diff feature master HEAD
diff --cc README.md
index ca2c305,ca2c305..24b898d
--- a/README.md
+++ b/README.md
@@@ -1,3 -1,3 +1,3 @@@
# MergeDiff
--Init - master changes
++Init - Work on feature

diff3可以做到。

Horba@cake ~/MergeDiff $ diff3 <(git show master:README.md) <(git show feature:README.md) <( cat README.md )
====1
1:1,3c
# MergeDiff
Init - master changes
2:0a
3:0a
====2
1:6c
3:3c
Init - Resolved
2:3c
Init - Work on feature

Answer 2

后像和原像存储在.git/rr-cache/$hex中。自动合并完成后，我们有一个文件，其内容与 postimage 相同。

这是一个快速而肮脏的bash函数，用于打印X的前像，或HEAD版本和原像之间的差异。副作用是将创建悬空的斑点。

# input: file path
# output: the preimage with conflict markers, 
#         or the diff between HEAD's version and the preimage. 
#         If the file path does not exist in rerere cache, return nothing.
function foo(){
p=$1
current=`git hash-object $p`
for hex in `ls .git/rr-cache`;do
posthash=`git hash-object .git/rr-cache/$hex/postimage`
if [ "$posthash" = "$current" ];then
git diff HEAD:$p $(git hash-object -w .git/rr-cache/$hex/preimage)
# To print the preimage
#cat .git/rr-cache/$hex/preimage
return
fi
done
}
foo a.c