1 files changed, 53 insertions, 0 deletions

diff --git a/services/pull/merge_squash.go b/services/pull/merge_squash.go
new file mode 100644
index 000000000..0a8cc0167
--- /dev/null
+++ b/services/pull/merge_squash.go
@@ -0,0 +1,53 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package pull
+
+import (
+	"fmt"
+
+	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+// doMergeStyleSquash squashes the tracking branch on the current HEAD (=base)
+func doMergeStyleSquash(ctx *mergeContext, message string) error {
+	cmd := git.NewCommand(ctx, "merge", "--squash").AddDynamicArguments(trackingBranch)
+	if err := runMergeCommand(ctx, repo_model.MergeStyleSquash, cmd); 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 len(ctx.signArg) == 0 {
+		if err := git.NewCommand(ctx, "commit").
+			AddOptionFormat("--author='%s <%s>'", sig.Name, sig.Email).
+			AddOptionFormat("--message=%s", message).
+			Run(ctx.RunOpts()); err != nil {
+			log.Error("git commit %-v: %v\n%s\n%s", ctx.pr, err, ctx.outbuf.String(), ctx.errbuf.String())
+			return fmt.Errorf("git commit [%s:%s -> %s:%s]: %w\n%s\n%s", ctx.pr.HeadRepo.FullName(), ctx.pr.HeadBranch, ctx.pr.BaseRepo.FullName(), ctx.pr.BaseBranch, err, ctx.outbuf.String(), ctx.errbuf.String())
+		}
+	} else {
+		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())
+		}
+		if err := git.NewCommand(ctx, "commit").
+			AddArguments(ctx.signArg...).
+			AddOptionFormat("--author='%s <%s>'", sig.Name, sig.Email).
+			AddOptionFormat("--message=%s", message).
+			Run(ctx.RunOpts()); err != nil {
+			log.Error("git commit %-v: %v\n%s\n%s", ctx.pr, err, ctx.outbuf.String(), ctx.errbuf.String())
+			return fmt.Errorf("git commit [%s:%s -> %s:%s]: %w\n%s\n%s", ctx.pr.HeadRepo.FullName(), ctx.pr.HeadBranch, ctx.pr.BaseRepo.FullName(), ctx.pr.BaseBranch, err, ctx.outbuf.String(), ctx.errbuf.String())
+		}
+	}
+	ctx.outbuf.Reset()
+	ctx.errbuf.Reset()
+	return nil
+}