Allow cherry-picking commits during a rebase

This can be useful when you know that a cherry-picked commit would conflict at
the tip of your branch, but doesn't at the beginning of the branch (or
somewhere in the middle). In that case you want to be able to edit the commit
before where you want to insert the cherry-picked commits, and then paste to
insert them into the todo list at that point.

pkg/commands/git_commands/rebase.go

@@ -457,6 +457,20 @@ func (self *RebaseCommands) CherryPickCommits(commits []*models.Commit) error {
 	}).Run()
 }
 
+// CherryPickCommitsDuringRebase simply prepends the given commits to the existing git-rebase-todo file
+func (self *RebaseCommands) CherryPickCommitsDuringRebase(commits []*models.Commit) error {
+	todoLines := lo.Map(commits, func(commit *models.Commit, _ int) daemon.TodoLine {
+		return daemon.TodoLine{
+			Action: "pick",
+			Commit: commit,
+		}
+	})
+
+	todo := daemon.TodoLinesToString(todoLines)
+	filePath := filepath.Join(self.repoPaths.worktreeGitDirPath, "rebase-merge/git-rebase-todo")
+	return utils.PrependStrToTodoFile(filePath, []byte(todo))
+}
+
 // we can't start an interactive rebase from the first commit without passing the
 // '--root' arg
 func getBaseShaOrRoot(commits []*models.Commit, index int) string {

pkg/gui/controllers/helpers/cherry_pick_helper.go

@@ -76,6 +76,19 @@ func (self *CherryPickHelper) Paste() error {
 		Title:  self.c.Tr.CherryPick,
 		Prompt: self.c.Tr.SureCherryPick,
 		HandleConfirm: func() error {
+			isInRebase, err := self.c.Git().Status.IsInInteractiveRebase()
+			if err != nil {
+				return err
+			}
+			if isInRebase {
+				if err := self.c.Git().Rebase.CherryPickCommitsDuringRebase(self.getData().CherryPickedCommits); err != nil {
+					return err
+				}
+				return self.c.Refresh(types.RefreshOptions{
+					Mode: types.SYNC, Scope: []types.RefreshableView{types.REBASE_COMMITS},
+				})
+			}
+
 			return self.c.WithWaitingStatus(self.c.Tr.CherryPickingStatus, func(gocui.Task) error {
 				self.c.LogAction(self.c.Tr.Actions.CherryPick)
 				err := self.c.Git().Rebase.CherryPickCommits(self.getData().CherryPickedCommits)

pkg/integration/tests/cherry_pick/cherry_pick_during_rebase.go

@@ -0,0 +1,87 @@
+package cherry_pick
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var CherryPickDuringRebase = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Cherry pick commits from the subcommits view during a rebase",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shell.
+			EmptyCommit("base").
+			NewBranch("first-branch").
+			NewBranch("second-branch").
+			Checkout("first-branch").
+			EmptyCommit("one").
+			EmptyCommit("two").
+			Checkout("second-branch").
+			EmptyCommit("three").
+			EmptyCommit("four").
+			Checkout("first-branch")
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Branches().
+			Focus().
+			Lines(
+				Contains("first-branch"),
+				Contains("second-branch"),
+				Contains("master"),
+			).
+			SelectNextItem().
+			PressEnter()
+
+		t.Views().SubCommits().
+			IsFocused().
+			Lines(
+				Contains("four").IsSelected(),
+				Contains("three"),
+				Contains("base"),
+			).
+			// copy commit 'three'
+			SelectNextItem().
+			Press(keys.Commits.CherryPickCopy)
+
+		t.Views().Information().Content(Contains("1 commit copied"))
+
+		t.Views().Commits().
+			Focus().
+			Lines(
+				Contains("CI two").IsSelected(),
+				Contains("CI one"),
+				Contains("CI base"),
+			).
+			SelectNextItem().
+			Press(keys.Universal.Edit).
+			Lines(
+				Contains("pick  CI two"),
+				Contains("      CI <-- YOU ARE HERE --- one").IsSelected(),
+				Contains("      CI base"),
+			).
+			Press(keys.Commits.PasteCommits).
+			Tap(func() {
+				t.ExpectPopup().Alert().
+					Title(Equals("Cherry-pick")).
+					Content(Contains("Are you sure you want to cherry-pick the copied commits onto this branch?")).
+					Confirm()
+			}).
+			Lines(
+				Contains("pick  CI two"),
+				Contains("pick  CI three"),
+				Contains("      CI <-- YOU ARE HERE --- one"),
+				Contains("      CI base"),
+			).
+			Tap(func() {
+				t.Common().ContinueRebase()
+			}).
+			Lines(
+				Contains("CI two"),
+				Contains("CI three"),
+				Contains("CI one"),
+				Contains("CI base"),
+			)
+	},
+})

pkg/integration/tests/test_list.go

@@ -55,6 +55,7 @@ var tests = []*components.IntegrationTest{
 	branch.Suggestions,
 	cherry_pick.CherryPick,
 	cherry_pick.CherryPickConflicts,
+	cherry_pick.CherryPickDuringRebase,
 	commit.AddCoAuthor,
 	commit.Amend,
 	commit.Commit,