Add test for deep symlink into repo

This is a test that covers jesseduffield#3144 and its dupe jesseduffield#3015, where lazygit
is run from a symlink outside of a repo into a subdirectory of that
repo.

pkg/integration/tests/test_list.go

@@ -277,5 +277,6 @@ var tests = []*components.IntegrationTest{
 	worktree.ForceRemoveWorktree,
 	worktree.RemoveWorktreeFromBranch,
 	worktree.ResetWindowTabs,
+	worktree.SymlinkIntoRepoSubdir,
 	worktree.WorktreeInRepo,
 }

pkg/integration/tests/worktree/symlink_into_repo_subdir.go

@@ -0,0 +1,62 @@
+package worktree
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var SymlinkIntoRepoSubdir = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Open lazygit in a symlink into a repo's subdirectory",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		// we're going to have a directory structure like this:
+		// project
+		//  - repo/a/b/c (main worktree with subdirs)
+		//  - link (symlink to repo/a/b/c)
+		//
+		shell.CreateFileAndAdd("a/b/c/blah", "blah\n")
+		shell.Commit("initial commit")
+		shell.UpdateFile("a/b/c/blah", "updated content\n")
+
+		shell.Chdir("..")
+		shell.RunCommand([]string{"ln", "-s", "repo/a/b/c", "link"})
+
+		shell.Chdir("link")
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Branches().
+			Lines(
+				Contains("master"),
+			)
+
+		t.Views().Commits().
+			Lines(
+				Contains("initial commit"),
+			)
+
+		t.Views().Files().
+			IsFocused().
+			Lines(
+				Contains(" a/b/c"),  // shows as modified
+				Contains(" M blah"), // shows as modified
+			).
+			PressPrimaryAction().
+			Press(keys.Files.CommitChanges)
+
+		t.ExpectPopup().CommitMessagePanel().
+			Title(Equals("Commit summary")).
+			Type("Add blah").
+			Confirm()
+
+		t.Views().Files().
+			IsEmpty()
+
+		t.Views().Commits().
+			Lines(
+				Contains("Add blah"),
+				Contains("initial commit"),
+			)
+	},
+})