Add test demonstrating the problem

For a worktree that contains submodules, trying to delete it shows an error and
doesn't offer to force-remove it.

pkg/integration/tests/test_list.go

@@ -455,6 +455,7 @@ var tests = []*components.IntegrationTest{
 	worktree.FastForwardWorktreeBranch,
 	worktree.FastForwardWorktreeBranchShouldNotPolluteCurrentWorktree,
 	worktree.ForceRemoveWorktree,
+	worktree.ForceRemoveWorktreeWithSubmodules,
 	worktree.RemoveWorktreeFromBranch,
 	worktree.ResetWindowTabs,
 	worktree.SymlinkIntoRepoSubdir,

pkg/integration/tests/worktree/force_remove_worktree_with_submodules.go

@@ -0,0 +1,58 @@
+package worktree
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var ForceRemoveWorktreeWithSubmodules = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Force remove a worktree that contains submodules",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shell.NewBranch("mybranch")
+		shell.CreateFileAndAdd("README.md", "hello world")
+		shell.Commit("initial commit")
+		shell.CloneIntoSubmodule("submodule", "submodule")
+		shell.Commit("Add submodule")
+		shell.AddWorktree("mybranch", "../linked-worktree", "newbranch")
+		shell.RunCommand([]string{"git", "-C", "../linked-worktree", "submodule", "update", "--init"})
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Worktrees().
+			Focus().
+			Lines(
+				Contains("repo (main)").IsSelected(),
+				Contains("linked-worktree"),
+			).
+			NavigateToLine(Contains("linked-worktree")).
+			Press(keys.Universal.Remove).
+			Tap(func() {
+				t.ExpectPopup().Confirmation().
+					Title(Equals("Remove worktree")).
+					Content(Equals("Are you sure you want to remove worktree 'linked-worktree'?")).
+					Confirm()
+
+				/* EXPECTED:
+				t.ExpectPopup().Confirmation().
+					Title(Equals("Remove worktree")).
+					Content(Equals("'linked-worktree' contains modified or untracked files, or submodules (or all of these). Are you sure you want to remove it?")).
+					Confirm()
+				ACTUAL: */
+				t.ExpectPopup().Alert().
+					Title(Equals("Error")).
+					Content(Equals("fatal: working trees containing submodules cannot be moved or removed")).
+					Confirm()
+			}).
+			/* EXPECTED:
+			Lines(
+				Contains("repo (main)").IsSelected(),
+			)
+			ACTUAL: */
+			Lines(
+				Contains("repo (main)"),
+				Contains("linked-worktree").IsSelected(),
+			)
+	},
+})