Fix reverting a merge commit failing (#28794) (#28825)

Backport https://github.com/go-gitea/gitea/pull/28794

Fixes #22236

---
Error occurring currently while trying to revert commit using read-tree
-m approach:
> 2022/12/26 16:04:43 ...rvices/pull/patch.go:240:AttemptThreeWayMerge()
[E] [63a9c61a] Unable to run read-tree -m! Error: exit status 128 -
fatal: this operation must be run in a work tree
> 	 - fatal: this operation must be run in a work tree

We need to clone a non-bare repository for `git read-tree -m` to work.

bb371aee6e
adds support to create a non-bare cloned temporary upload repository.

After cloning a non-bare temporary upload repository, we [set default
index](https://github.com/go-gitea/gitea/blob/main/services/repository/files/cherry_pick.go#L37)
(`git read-tree HEAD`).
This operation ends up resetting the git index file (see investigation
details below), due to which, we need to call `git update-index
--refresh` afterward.

Here's the diff of the index file before and after we execute
SetDefaultIndex: https://www.diffchecker.com/hyOP3eJy/

Notice the **ctime**, **mtime** are set to 0 after SetDefaultIndex.

You can reproduce the same behavior using these steps:
```bash
$ git clone https://try.gitea.io/me-heer/test.git -s -b main
$ cd test
$ git read-tree HEAD
$ git read-tree -m 1f085d7ed8 1f085d7ed8 9933caed00
error: Entry '1' not uptodate. Cannot merge.
```

After which, we can fix like this:
```bash
$ git update-index --refresh
$ git read-tree -m 1f085d7ed8 1f085d7ed8 9933caed00
```

(cherry picked from commit 62f2d717b7)
This commit is contained in:
Mihir Joshi 2024-01-21 19:48:37 +05:30 committed by Earl Warren
parent cdaf0dc752
commit 54a6dc73ef
No known key found for this signature in database
GPG key ID: 0579CB2928A78A00
7 changed files with 24 additions and 8 deletions

View file

@ -267,7 +267,7 @@ func alterRepositoryContent(ctx context.Context, doer *user_model.User, repo *re
defer t.Close()
var lastCommitID string
if err := t.Clone(repo.DefaultBranch); err != nil {
if err := t.Clone(repo.DefaultBranch, true); err != nil {
if !git.IsErrBranchNotExist(err) || !repo.IsEmpty {
return err
}

View file

@ -31,12 +31,15 @@ func CherryPick(ctx context.Context, repo *repo_model.Repository, doer *user_mod
log.Error("%v", err)
}
defer t.Close()
if err := t.Clone(opts.OldBranch); err != nil {
if err := t.Clone(opts.OldBranch, false); err != nil {
return nil, err
}
if err := t.SetDefaultIndex(); err != nil {
return nil, err
}
if err := t.RefreshIndex(); err != nil {
return nil, err
}
// Get the commit of the original branch
commit, err := t.GetBranchCommit(opts.OldBranch)

View file

@ -21,7 +21,7 @@ func GetDiffPreview(ctx context.Context, repo *repo_model.Repository, branch, tr
return nil, err
}
defer t.Close()
if err := t.Clone(branch); err != nil {
if err := t.Clone(branch, true); err != nil {
return nil, err
}
if err := t.SetDefaultIndex(); err != nil {

View file

@ -108,7 +108,7 @@ func ApplyDiffPatch(ctx context.Context, repo *repo_model.Repository, doer *user
log.Error("%v", err)
}
defer t.Close()
if err := t.Clone(opts.OldBranch); err != nil {
if err := t.Clone(opts.OldBranch, true); err != nil {
return nil, err
}
if err := t.SetDefaultIndex(); err != nil {

View file

@ -51,8 +51,13 @@ func (t *TemporaryUploadRepository) Close() {
}
// Clone the base repository to our path and set branch as the HEAD
func (t *TemporaryUploadRepository) Clone(branch string) error {
if _, _, err := git.NewCommand(t.ctx, "clone", "-s", "--bare", "-b").AddDynamicArguments(branch, t.repo.RepoPath(), t.basePath).RunStdString(nil); err != nil {
func (t *TemporaryUploadRepository) Clone(branch string, bare bool) error {
cmd := git.NewCommand(t.ctx, "clone", "-s", "-b").AddDynamicArguments(branch, t.repo.RepoPath(), t.basePath)
if bare {
cmd.AddArguments("--bare")
}
if _, _, err := cmd.RunStdString(nil); err != nil {
stderr := err.Error()
if matched, _ := regexp.MatchString(".*Remote branch .* not found in upstream origin.*", stderr); matched {
return git.ErrBranchNotExist{
@ -98,6 +103,14 @@ func (t *TemporaryUploadRepository) SetDefaultIndex() error {
return nil
}
// RefreshIndex looks at the current index and checks to see if merges or updates are needed by checking stat() information.
func (t *TemporaryUploadRepository) RefreshIndex() error {
if _, _, err := git.NewCommand(t.ctx, "update-index", "--refresh").RunStdString(&git.RunOpts{Dir: t.basePath}); err != nil {
return fmt.Errorf("RefreshIndex: %w", err)
}
return nil
}
// LsFiles checks if the given filename arguments are in the index
func (t *TemporaryUploadRepository) LsFiles(filenames ...string) ([]string, error) {
stdOut := new(bytes.Buffer)

View file

@ -141,7 +141,7 @@ func ChangeRepoFiles(ctx context.Context, repo *repo_model.Repository, doer *use
}
defer t.Close()
hasOldBranch := true
if err := t.Clone(opts.OldBranch); err != nil {
if err := t.Clone(opts.OldBranch, true); err != nil {
for _, file := range opts.Files {
if file.Operation == "delete" {
return nil, err

View file

@ -87,7 +87,7 @@ func UploadRepoFiles(ctx context.Context, repo *repo_model.Repository, doer *use
defer t.Close()
hasOldBranch := true
if err = t.Clone(opts.OldBranch); err != nil {
if err = t.Clone(opts.OldBranch, true); err != nil {
if !git.IsErrBranchNotExist(err) || !repo.IsEmpty {
return err
}