Improve squash merge commit author and co-author with private emails (#22977)

When emails addresses are private, squash merges always use
`@noreply.localhost` for the author of the squash commit. And the author
is redundantly added as a co-author in the commit message.

Also without private mails, the redundant co-author is possible when
committing with a signature that's different than the user full name and
primary email.

Now try to find a commit by the same user in the list of commits, and
prefer the signature from that over one constructed from the account
settings.

diff --git a/services/pull/merge_squash.go b/services/pull/merge_squash.go
index d6e7314988d38aebcdb39e000db3f0803fcbc79b..f52a2301d906c7059c8b1c9e4930d60246c88926 100644 (file)
--- a/services/pull/merge_squash.go
+++ b/services/pull/merge_squash.go
@@ -7,24 +7,62 @@ import (
        "fmt"
 
        repo_model "code.gitea.io/gitea/models/repo"
+       user_model "code.gitea.io/gitea/models/user"
+       "code.gitea.io/gitea/modules/container"
        "code.gitea.io/gitea/modules/git"
        "code.gitea.io/gitea/modules/log"
        "code.gitea.io/gitea/modules/setting"
 )
 
+// doMergeStyleSquash gets a commit author signature for squash commits
+func getAuthorSignatureSquash(ctx *mergeContext) (*git.Signature, error) {
+       if err := ctx.pr.Issue.LoadPoster(ctx); err != nil {
+               log.Error("%-v Issue[%d].LoadPoster: %v", ctx.pr, ctx.pr.Issue.ID, err)
+               return nil, err
+       }
+
+       // Try to get an signature from the same user in one of the commits, as the
+       // poster email might be private or commits might have a different signature
+       // than the primary email address of the poster.
+       gitRepo, closer, err := git.RepositoryFromContextOrOpen(ctx, ctx.tmpBasePath)
+       if err != nil {
+               log.Error("%-v Unable to open base repository: %v", ctx.pr, err)
+               return nil, err
+       }
+       defer closer.Close()
+
+       commits, err := gitRepo.CommitsBetweenIDs(trackingBranch, "HEAD")
+       if err != nil {
+               log.Error("%-v Unable to get commits between: %s %s: %v", ctx.pr, "HEAD", trackingBranch, err)
+               return nil, err
+       }
+
+       uniqueEmails := make(container.Set[string])
+       for _, commit := range commits {
+               if commit.Author != nil && uniqueEmails.Add(commit.Author.Email) {
+                       commitUser, _ := user_model.GetUserByEmail(ctx, commit.Author.Email)
+                       if commitUser != nil && commitUser.ID == ctx.pr.Issue.Poster.ID {
+                               return commit.Author, nil
+                       }
+               }
+       }
+
+       return ctx.pr.Issue.Poster.NewGitSig(), nil
+}
+
 // doMergeStyleSquash squashes the tracking branch on the current HEAD (=base)
 func doMergeStyleSquash(ctx *mergeContext, message string) error {
+       sig, err := getAuthorSignatureSquash(ctx)
+       if err != nil {
+               return fmt.Errorf("getAuthorSignatureSquash: %w", err)
+       }
+
        cmdMerge := git.NewCommand(ctx, "merge", "--squash").AddDynamicArguments(trackingBranch)
        if err := runMergeCommand(ctx, repo_model.MergeStyleSquash, cmdMerge); err != nil {
                log.Error("%-v Unable to merge --squash tracking into base: %v", ctx.pr, err)
                return err
        }
 
-       if err := ctx.pr.Issue.LoadPoster(ctx); err != nil {
-               log.Error("%-v Issue[%d].LoadPoster: %v", ctx.pr, ctx.pr.Issue.ID, err)
-               return fmt.Errorf("LoadPoster: %w", err)
-       }
-       sig := ctx.pr.Issue.Poster.NewGitSig()
        if setting.Repository.PullRequest.AddCoCommitterTrailers && ctx.committer.String() != sig.String() {
                // add trailer
                message += fmt.Sprintf("\nCo-authored-by: %s\nCo-committed-by: %s\n", sig.String(), sig.String())

diff --git a/services/pull/pull.go b/services/pull/pull.go
index d8923d0d57251b7a0e04630e1654b34c1c764542..e40e59a2c500270e286b342da6db44f50fb9e2e1 100644 (file)
--- a/services/pull/pull.go
+++ b/services/pull/pull.go
@@ -669,7 +669,12 @@ func GetSquashMergeCommitMessages(ctx context.Context, pr *issues_model.PullRequ
 
                authorString := commit.Author.String()
                if uniqueAuthors.Add(authorString) && authorString != posterSig {
-                       authors = append(authors, authorString)
+                       // Compare use account as well to avoid adding the same author multiple times
+                       // times when email addresses are private or multiple emails are used.
+                       commitUser, _ := user_model.GetUserByEmail(ctx, commit.Author.Email)
+                       if commitUser == nil || commitUser.ID != pr.Issue.Poster.ID {
+                               authors = append(authors, authorString)
+                       }
                }
        }
 
@@ -690,7 +695,10 @@ func GetSquashMergeCommitMessages(ctx context.Context, pr *issues_model.PullRequ
                        for _, commit := range commits {
                                authorString := commit.Author.String()
                                if uniqueAuthors.Add(authorString) && authorString != posterSig {
-                                       authors = append(authors, authorString)
+                                       commitUser, _ := user_model.GetUserByEmail(ctx, commit.Author.Email)
+                                       if commitUser == nil || commitUser.ID != pr.Issue.Poster.ID {
+                                               authors = append(authors, authorString)
+                                       }
                                }
                        }
                        skip += limit