`git merge --no-overwrite-ignore` overwrites ignored files when merge (i.e. not fast-forward)

`git merge --no-overwrite-ignore` overwrites ignored files when merge (i.e. not fast-forward)

[Han Jiang]

Thank you for filling out a Git bug report!
Please answer the following questions to help us understand your issue.

What did you do before the bug happened? (Steps to reproduce your issue)

(`git merge --no-overwrite-ignore` overwrites ignored files when merge
with conflict.)
cd '/'; cd '/'; rm --force --recursive -- './test_git'; mkdir "$_"; cd "$_";
mkdir --parents -- './repo';
git init './repo'
echo '1' >'./repo/file_conflict'; git -C './repo' add
'./file_conflict'; git -C './repo' commit -m "$((++number))"
git -C './repo' branch branch2
git -C './repo' checkout -b branch1; echo 'file' >'./repo/.gitignore';
git -C './repo' add './.gitignore'; echo '2' >'./repo/file_conflict';
git -C './repo' add './file_conflict'; git -C './repo' commit -m
"$((++number))"
git -C './repo' checkout branch2; echo '1' >'./repo/file'; git -C
'./repo' add './file'; echo '3' >'./repo/file_conflict'; git -C
'./repo' add './file_conflict'; git -C './repo' commit -m
"$((++number))"
git -C './repo' checkout branch1
echo '2' >'./repo/file';
git -C './repo' log --graph --all --patch
git -C './repo' status --verbose --verbose
cat './repo/file'
git -C './repo' merge -m "$((++number))" --no-overwrite-ignore branch2
git -C './repo' log --graph --all --patch
git -C './repo' status --verbose --verbose
cat './repo/file'

(`git merge --no-overwrite-ignore` overwrites ignored files when merge
without conflict.)
cd '/'; cd '/'; rm --force --recursive -- './test_git'; mkdir "$_"; cd "$_";
mkdir --parents -- './repo';
git init './repo'
git -C './repo' commit -m "$((++number))" --allow-empty
git -C './repo' branch branch2
git -C './repo' checkout -b branch1; echo 'file' >'./repo/.gitignore';
git -C './repo' add './.gitignore'; git -C './repo' commit -m
"$((++number))"
git -C './repo' checkout branch2; echo '1' >'./repo/file'; git -C
'./repo' add './file'; git -C './repo' commit -m "$((++number))"
git -C './repo' checkout branch1
echo '2' >'./repo/file';
git -C './repo' log --graph --all --patch
git -C './repo' status --verbose --verbose
cat './repo/file'
git -C './repo' merge -m "$((++number))" --no-overwrite-ignore branch2
git -C './repo' log --graph --all --patch
git -C './repo' status --verbose --verbose
cat './repo/file'

What did you expect to happen? (Expected behavior)

`git merge --no-overwrite-ignore` refuses to overwrite ignored files
when merge with conflict.
`git merge --no-overwrite-ignore` refuses to overwrite ignored files
when merge without conflict.

What happened instead? (Actual behavior)

`git merge --no-overwrite-ignore` overwrites ignored files when merge
with conflict.
`git merge --no-overwrite-ignore` overwrites ignored files when merge
without conflict.

What's different between what you expected and what actually happened?

Anything else you want to add:

(`git merge --no-overwrite-ignore` refuses to overwrite ignored files
when fast-forward.)
cd '/'; cd '/'; rm --force --recursive -- './test_git'; mkdir "$_"; cd "$_";
mkdir --parents -- './repo';
git init './repo'
branch_default_path="$(git -C './repo' symbolic-ref HEAD)"
branch_default_name="${branch_default_path#'refs/heads/'}"
echo 'file' >'./repo/.gitignore'; git -C './repo' add './.gitignore';
git -C './repo' commit -m "$((++number))"
git -C './repo' branch branch1
rm './repo/.gitignore'; git -C './repo' add './.gitignore'; echo '1'
>'./repo/file'; git -C './repo' add './file'; git -C './repo' commit
-m "$((++number))"
git -C './repo' checkout branch1
echo '2' >'./repo/file';
git -C './repo' log --graph --all --patch
git -C './repo' status --verbose --verbose
cat './repo/file'
git -C './repo' merge -m "$((++number))" --no-overwrite-ignore
"$branch_default_name"
git -C './repo' log --graph --all --patch
git -C './repo' status --verbose --verbose
cat './repo/file'

Please review the rest of the bug report below.
You can delete any lines you don't wish to share.


[System Info]
git version:
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
uname: Windows 10.0 22631
compiler info: gnuc: 14.1
libc info: no libc information available
$SHELL (typically, interactive shell): C:\Program Files\Git\usr\bin\bash.exe


[Enabled Hooks]
not run from a git repository - no hooks to show

Re: `git merge --no-overwrite-ignore` overwrites ignored files when merge (i.e. not fast-forward)

[Elijah Newren]

On Sun, Sep 1, 2024, 03:49 Han Jiang <jhcarl0814@gmail.com> wrote:
>
> Thank you for filling out a Git bug report!
> Please answer the following questions to help us understand your issue.
>
> What did you do before the bug happened? (Steps to reproduce your issue)
>
> (`git merge --no-overwrite-ignore` overwrites ignored files when merge
> with conflict.)
>
> (`git merge --no-overwrite-ignore` overwrites ignored files when merge
> without conflict.)


Yep, well-known issue that I've mentioned multiple times.  Somewhat
related to the "precious" concept that has come up on the list a few
times.  See e.g.

  * the "merge backends" section of
https://lore.kernel.org/git/pull.1627.git.1703643931314.gitgitgadget@gmail.com/
  * C2-C7 of https://lore.kernel.org/git/CABPp-BEg6vxiUp
  * affects cherry-pick too, with discussion of how merge is affected:
https://lore.kernel.org/git/CABPp-BG=pm8gfRZNW8Rk1V77s40Do1FZy0mxH6epubHbzF8U5w@mail.gmail.com/
  * merge and other shortcomings mentioned when fixing up default
handling of ignored files:
https://lore.kernel.org/git/b7fe354effff8da3de53bd9cc40a03b5fd455f67.1632760428.git.gitgitgadget@gmail.com/
  * wider discussion of correctly removing or keeping files (also
discussing merge), in a series fixing lots of bugs in the area:
https://lore.kernel.org/git/pull.1036.v3.git.1632760428.gitgitgadget@gmail.com/

Re: `git merge --no-overwrite-ignore` overwrites ignored files when merge (i.e. not fast-forward)

[Han Jiang]

(https://lore.kernel.org/git/CABPp-BEg6vxiUp/ says: Message-ID
<CABPp-BEg6vxiUp> not found)
Many thanks to your leading me to the "Precious Files Design Document"
and all the other links!
The document reveals that untracked files would better be further
subdivided and explains the meaning of each category. Really clear and
understandable! Turns out that the support of --[no-]overwrite-ignore
is not enough (only works with the fast-forwarding backend), so maybe
users have to wait until they deal with all those issues in a unified
way.

On Wed, Sep 4, 2024 at 11:19 AM Elijah Newren <newren@gmail.com> wrote:
>
> On Sun, Sep 1, 2024, 03:49 Han Jiang <jhcarl0814@gmail.com> wrote:
> >
> > Thank you for filling out a Git bug report!
> > Please answer the following questions to help us understand your issue.
> >
> > What did you do before the bug happened? (Steps to reproduce your issue)
> >
> > (`git merge --no-overwrite-ignore` overwrites ignored files when merge
> > with conflict.)
> >
> > (`git merge --no-overwrite-ignore` overwrites ignored files when merge
> > without conflict.)
>
>
> Yep, well-known issue that I've mentioned multiple times.  Somewhat
> related to the "precious" concept that has come up on the list a few
> times.  See e.g.
>
>   * the "merge backends" section of
> https://lore.kernel.org/git/pull.1627.git.1703643931314.gitgitgadget@gmail.com/
>   * C2-C7 of https://lore.kernel.org/git/CABPp-BEg6vxiUp
>   * affects cherry-pick too, with discussion of how merge is affected:
> https://lore.kernel.org/git/CABPp-BG=pm8gfRZNW8Rk1V77s40Do1FZy0mxH6epubHbzF8U5w@mail.gmail.com/
>   * merge and other shortcomings mentioned when fixing up default
> handling of ignored files:
> https://lore.kernel.org/git/b7fe354effff8da3de53bd9cc40a03b5fd455f67.1632760428.git.gitgitgadget@gmail.com/
>   * wider discussion of correctly removing or keeping files (also
> discussing merge), in a series fixing lots of bugs in the area:
> https://lore.kernel.org/git/pull.1036.v3.git.1632760428.gitgitgadget@gmail.com/