fix: add confirmation when checking out file with local changes

pkg/gui/controllers/commits_files_controller.go

@@ -283,14 +283,25 @@ func (self *CommitFilesController) openCopyMenu() error {
 }
 
 func (self *CommitFilesController) checkout(node *filetree.CommitFileNode) error {
-	self.c.LogAction(self.c.Tr.Actions.CheckoutFile)
-	_, to := self.context().GetFromAndToForDiff()
-	if err := self.c.Git().WorkingTree.CheckoutFile(to, node.GetPath()); err != nil {
-		return err
-	}
+	// Check if the file has uncommitted local changes
+	hasLocalChanges := lo.SomeBy(self.c.Model().Files, func(file *models.File) bool {
+		return file.GetPath() == node.GetPath() && (file.HasStagedChanges || file.HasUnstagedChanges)
+	})
 
-	self.c.Refresh(types.RefreshOptions{Mode: types.ASYNC})
-	return nil
+	return self.c.ConfirmIf(hasLocalChanges, types.ConfirmOpts{
+		Title:  self.c.Tr.CheckoutFileFromCommitTitle,
+		Prompt: self.c.Tr.CheckoutFileFromCommitPrompt,
+		HandleConfirm: func() error {
+			self.c.LogAction(self.c.Tr.Actions.CheckoutFile)
+			_, to := self.context().GetFromAndToForDiff()
+			if err := self.c.Git().WorkingTree.CheckoutFile(to, node.GetPath()); err != nil {
+				return err
+			}
+
+			self.c.Refresh(types.RefreshOptions{Mode: types.ASYNC})
+			return nil
+		},
+	})
 }
 
 func (self *CommitFilesController) discard(selectedNodes []*filetree.CommitFileNode) error {

pkg/i18n/english.go

@@ -425,6 +425,8 @@ type TranslationSet struct {
 	ViewItemFiles                         string
 	CommitFilesTitle                      string
 	CheckoutCommitFileTooltip             string
+	CheckoutFileFromCommitTitle           string
+	CheckoutFileFromCommitPrompt          string
 	CanOnlyDiscardFromLocalCommits        string
 	Remove                                string
 	DiscardOldFileChangeTooltip           string
@@ -1525,6 +1527,8 @@ func EnglishTranslationSet() *TranslationSet {
 		ViewItemFiles:                        "View files",
 		CommitFilesTitle:                     "Commit files",
 		CheckoutCommitFileTooltip:            "Checkout file. This replaces the file in your working tree with the version from the selected commit.",
+		CheckoutFileFromCommitTitle:          "Checkout file from commit",
+		CheckoutFileFromCommitPrompt:         "Are you sure you want to checkout this file? Your uncommitted changes will be lost.",
 		CanOnlyDiscardFromLocalCommits:       "Changes can only be discarded from local commits",
 		Remove:                               "Remove",
 		DiscardOldFileChangeTooltip:          "Discard this commit's changes to this file. This runs an interactive rebase in the background, so you may get a merge conflict if a later commit also changes this file.",

pkg/integration/tests/commit/checkout_file_from_commit_with_local_changes.go

@@ -0,0 +1,55 @@
+package commit
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var CheckoutFileFromCommitWithLocalChanges = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Checkout a file from a commit when there are local changes, showing a confirmation",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shell.CreateFileAndAdd("file.txt", "one\n")
+		shell.Commit("one")
+		shell.CreateFileAndAdd("file.txt", "two\n")
+		shell.Commit("two")
+		shell.CreateFileAndAdd("file.txt", "three\n")
+		shell.Commit("three")
+		// Create local uncommitted changes
+		shell.UpdateFile("file.txt", "local changes\n")
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Commits().
+			Focus().
+			Lines(
+				Contains("three").IsSelected(),
+				Contains("two"),
+				Contains("one"),
+			).
+			NavigateToLine(Contains("two")).
+			PressEnter()
+
+		t.Views().CommitFiles().
+			IsFocused().
+			Lines(
+				Equals("M file.txt"),
+			).
+			Press(keys.CommitFiles.CheckoutCommitFile)
+
+		// Should show confirmation dialog
+		t.ExpectPopup().Confirmation().
+			Title(Equals("Checkout file from commit")).
+			Content(Contains("Are you sure you want to checkout this file? Your uncommitted changes will be lost.")).
+			Confirm()
+
+		// After confirmation, file should be checked out
+		t.Views().Files().
+			Lines(
+				Equals("M  file.txt"),
+			)
+
+		t.FileSystem().FileContent("file.txt", Equals("two\n"))
+	},
+})

pkg/integration/tests/test_list.go

@@ -106,6 +106,7 @@ var tests = []*components.IntegrationTest{
 	commit.AutoWrapMessage,
 	commit.Checkout,
 	commit.CheckoutFileFromCommit,
+	commit.CheckoutFileFromCommitWithLocalChanges,
 	commit.CheckoutFileFromRangeSelectionOfCommits,
 	commit.Commit,
 	commit.CommitMultiline,