Fix checking out a tag when there is a branch with the same name (#3179)

pkg/gui/controllers/tags_controller.go

@@ -83,7 +83,7 @@ func (self *TagsController) GetOnRenderToMain() func() error {
 
 func (self *TagsController) checkout(tag *models.Tag) error {
 	self.c.LogAction(self.c.Tr.Actions.CheckoutTag)
-	if err := self.c.Helpers().Refs.CheckoutRef(tag.Name, types.CheckoutRefOptions{}); err != nil {
+	if err := self.c.Helpers().Refs.CheckoutRef(tag.FullRefName(), types.CheckoutRefOptions{}); err != nil {
 		return err
 	}
 	return self.c.PushContext(self.c.Contexts().Branches)

pkg/integration/tests/tag/checkout_when_branch_with_same_name_exists.go

@@ -0,0 +1,34 @@
+package tag
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var CheckoutWhenBranchWithSameNameExists = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Checkout a tag when there's a branch with the same name",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shell.EmptyCommit("one")
+		shell.NewBranch("tag")
+		shell.Checkout("master")
+		shell.EmptyCommit("two")
+		shell.CreateLightweightTag("tag", "HEAD")
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Tags().
+			Focus().
+			Lines(
+				Contains("tag").IsSelected(),
+			).
+			PressPrimaryAction() // checkout tag
+
+		t.Views().Branches().IsFocused().Lines(
+			Contains("HEAD detached at tag").IsSelected(),
+			Contains("master"),
+			Contains("tag"),
+		)
+	},
+})

pkg/integration/tests/test_list.go

@@ -245,6 +245,7 @@ var tests = []*components.IntegrationTest{
 	sync.PushWithCredentialPrompt,
 	sync.RenameBranchAndPull,
 	tag.Checkout,
+	tag.CheckoutWhenBranchWithSameNameExists,
 	tag.CreateWhileCommitting,
 	tag.CrudAnnotated,
 	tag.CrudLightweight,