s

gitcmd/merge_temprepo.go

@@ -0,0 +1,101 @@
+package gitcmd
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+func (r *Repository) tempWorkingClone(branch string) (temp string, cleanup func(), err error) {
+	dir, err := os.MkdirTemp("", "simplegit-temprepo-*")
+	if err != nil {
+		return "", nil, err
+	}
+	temp = filepath.Join(dir, "repo")
+	cleanup = func() { _ = os.RemoveAll(dir) }
+	cmd := NewCommand("clone", "--shared").AddOptionValues("-b", branch).AddDynamicArguments(r.Path, temp)
+	if _, _, err := cmd.RunStdString(r.ctx); err != nil {
+		cleanup()
+		return "", nil, fmt.Errorf("temp clone: %w", err)
+	}
+	return temp, cleanup, nil
+}
+
+func (r *Repository) unmergedPaths(dir string) ([]string, error) {
+	out, _, err := NewCommand("diff", "--name-only", "--diff-filter=U").WithDir(dir).RunStdString(r.ctx)
+	if err != nil {
+		return nil, err
+	}
+	var paths []string
+	for _, l := range strings.Split(out, "\n") {
+		if l = strings.TrimSpace(l); l != "" {
+			paths = append(paths, l)
+		}
+	}
+	return paths, nil
+}
+
+func (r *Repository) MergeViaTempRepo(base, head, message, authorName, authorEmail string, noFF bool) (*MergeResult, error) {
+	baseSHA, err := r.refSHA("refs/heads/" + base)
+	if err != nil || baseSHA == "" {
+		return nil, fmt.Errorf("base branch %q not found", base)
+	}
+	headSHA, err := r.refSHA("refs/heads/" + head)
+	if err != nil || headSHA == "" {
+		return nil, fmt.Errorf("head branch %q not found", head)
+	}
+
+	temp, cleanup, err := r.tempWorkingClone(base)
+	if err != nil {
+		return nil, err
+	}
+	defer cleanup()
+
+	if !noFF && r.isAncestor(baseSHA, headSHA) {
+		if _, _, err := NewCommand("merge", "--ff-only").AddDynamicArguments(headSHA).WithDir(temp).RunStdString(r.ctx); err != nil {
+			return nil, fmt.Errorf("merge --ff-only: %w", err)
+		}
+		if err := r.pushBack(temp, base, headSHA, baseSHA); err != nil {
+			return nil, err
+		}
+		hc, err := r.GetCommit(headSHA)
+		if err != nil {
+			return nil, err
+		}
+		return &MergeResult{Base: base, Head: head, MergeCommit: hc, FastForward: true}, nil
+	}
+
+	_, _, mergeErr := NewCommand("merge", "--no-ff", "--no-commit").
+		AddDynamicArguments(headSHA).WithDir(temp).RunStdString(r.ctx)
+	if mergeErr != nil {
+
+		var exitErr *exec.ExitError
+		if !errors.As(mergeErr, &exitErr) {
+			return nil, fmt.Errorf("merge: %w", mergeErr)
+		}
+		conflicts, _ := r.unmergedPaths(temp)
+		_, _, _ = NewCommand("merge", "--abort").WithDir(temp).RunStdString(r.ctx)
+		return &MergeResult{Base: base, Head: head, Conflicts: conflicts}, nil
+	}
+
+	treeOut, _, err := NewCommand("write-tree").WithDir(temp).RunStdString(r.ctx)
+	if err != nil {
+		return nil, fmt.Errorf("write-tree: %w", err)
+	}
+	mergedTree := strings.TrimSpace(treeOut)
+	commitSHA, err := r.commitTree(mergedTree, message, authorName, authorEmail, temp, baseSHA, headSHA)
+	if err != nil {
+		return nil, err
+	}
+	if err := r.pushBack(temp, base, commitSHA, baseSHA); err != nil {
+		return nil, err
+	}
+	mc, err := r.GetCommit(commitSHA)
+	if err != nil {
+		return nil, err
+	}
+	return &MergeResult{Base: base, Head: head, MergeCommit: mc}, nil
+}