merge.renames not work

[ZeroChiLi]

• I was not able to find an open or closed issue matching what I'm seeing

Setup

• Which version of Git for Windows are you using? Is it 32-bit or 64-bit?

$ git --version --build-options

git version 2.46.0.windows.1
cpu: x86_64
built from commit: 2e6a859ffc0471f60f79c1256f766042b0d5d17d
sizeof-long: 4
sizeof-size_t: 8
shell-path: D:/git-sdk-64-build-installers/usr/bin/sh
feature: fsmonitor--daemon
libcurl: 8.9.0
OpenSSL: OpenSSL 3.2.2 4 Jun 2024
zlib: 1.3.1

• Which version of Windows are you running? Vista, 7, 8, 10? Is it 32-bit or 64-bit?

$ cmd.exe /c ver

Microsoft Windows [Version 10.0.19045.4780]

• What options did you set as part of the installation? Or did you choose the
  defaults?

# One of the following:
> type "C:\Program Files\Git\etc\install-options.txt"
> type "C:\Program Files (x86)\Git\etc\install-options.txt"
> type "%USERPROFILE%\AppData\Local\Programs\Git\etc\install-options.txt"
> type "$env:USERPROFILE\AppData\Local\Programs\Git\etc\install-options.txt"
$ cat /etc/install-options.txt

"C:\Program Files\Git\etc\install-options.txt"

• Any other interesting things about your environment that might be related
  to the issue you're seeing?

no

Details

• Which terminal/shell are you running Git from? e.g Bash/CMD/PowerShell/other

CMD

• What commands did you run to trigger this issue? If you can provide a
  Minimal, Complete, and Verifiable example
  this will help us understand the issue.

git merge xxxxx

• What did you expect to occur after running these commands?

no

• What actually happened instead?

When I perform the merge operation, the result of find_renames in diffcore-rename.c is not what I expected, comparing two unrelated objects. I want to merge branches using merge when I turn off rename checking, I have set up git config merge.renames=false, but the code doesn't seem to support it?

//merge-ort.c
	/*
	 * detect_renames, verbosity, buffer_output, and obuf are ignored
	 * fields that were used by "recursive" rather than "ort" -- but
	 * sanity check them anyway.
	 */
	assert(opt->detect_renames >= -1 &&
	       opt->detect_renames <= DIFF_DETECT_COPY);

• If the problem was occurring with a specific repository, can you provide the
  URL to that repository to help us with testing?

no

[dscho]

When I perform the merge operation, the result of find_renames in diffcore-rename.c is not what I expected, comparing two unrelated objects. I want to merge branches using merge when I turn off rename checking, I have set up git config merge.renames=false, but the code doesn't seem to support it?

//merge-ort.c
	/*
	 * detect_renames, verbosity, buffer_output, and obuf are ignored
	 * fields that were used by "recursive" rather than "ort" -- but
	 * sanity check them anyway.
	 */
	assert(opt->detect_renames >= -1 &&
	       opt->detect_renames <= DIFF_DETECT_COPY);

@ZeroChiLi Could you help us understand what you mean? One good way to do that would be to provide a Minimal, Complete, and Verifiable example, i.e. a detailed, step-by-step description that sets up a fresh Git repository and demonstrates precisely what is going wrong, by example.

[ZeroChiLi]

My project is very large and it may take some time to reproduce a mini project. My main problem is that there is no way to turn off the detect_rename when merging.
I tried git config merge.renames false，but detect_rename is still checked when merging branches.

[dscho]

there is no way to turn off the detect_rename when merging.

If this is really true, then something very simple like this should reproduce the bug (and I am a bit miffed that it was me who needed to write this, I specifically asked you to provide such an example, I will conclude my involvement in this ticket after this, as a consequence):

git init test-renames
cd test-renames

echo a >a
git add a
git commit -m a

# start a branch that renames the file
git mv a b
git commit -m rename

# start another branch that modifies the file
git reset --hard HEAD^
echo c >a
git commit -c a

# now merge, turning off rename detection
git -c merge.renames=false merge HEAD@{2}

# now test whether the file `b` has the contents `c`,
# which would mean that the rename was detected, still

[ZeroChiLi]

I apologize for the misunderstanding; I thought it was an example where the result of the find_renames function was not as expected. Also, thank you for the example.

[dscho]

@ZeroChiLi so this is not a bug? Or is it a bug? If the latter, please modify the provided shell script until it reproduces the issue you seek to report.