Fix display of renamed files in tree view (#4452)

- **PR Description**

Fix a regression (introduced with the root item PR, #4346) that caused
renamed files to be displayed with their full path in tree view.

While fixing this I noticed that the display of moved files is a bit
confusing; for example, you can't distinguish a file being moved from
the root level into a directory from one that was renamed inside the
directory; see commit message of the first commit for more. I'm not
doing anything about this right now, just fix the regression for now.

Labeled as "ignore-for-release" because it fixes a regression in code
that wasn't released yet.

- **Please check if the PR fulfills these requirements**

* [x] Cheatsheets are up-to-date (run `go generate ./...`)
* [x] Code has been formatted (see
[here](https://github.com/jesseduffield/lazygit/blob/master/CONTRIBUTING.md#code-formatting))
* [x] Tests have been added/updated (see
[here](https://github.com/jesseduffield/lazygit/blob/master/pkg/integration/README.md)
for the integration test guide)
* [ ] Text is internationalised (see
[here](https://github.com/jesseduffield/lazygit/blob/master/CONTRIBUTING.md#internationalisation))
* [ ] If a new UserConfig entry was added, make sure it can be
hot-reloaded (see
[here](https://github.com/jesseduffield/lazygit/blob/master/docs/dev/Codebase_Guide.md#using-userconfig))
* [ ] Docs have been updated if necessary
* [x] You've read through your own file changes for silly mistakes etc

Author: stefanhaller

pkg/gui/presentation/files.go

@@ -308,7 +308,7 @@ func fileNameAtDepth(node *filetree.Node[models.File], depth int) string {
 	name := join(splitName[depth:])
 
 	if node.File != nil && node.File.IsRename() {
-		splitPrevName := split(node.File.PreviousPath)
+		splitPrevName := split("./" + node.File.PreviousPath)
 
 		prevName := node.File.PreviousPath
 		// if the file has just been renamed inside the same directory, we can shave off

pkg/integration/tests/file/renamed_files.go

@@ -0,0 +1,36 @@
+package file
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var RenamedFiles = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Regression test for the display of renamed files in the file tree",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig: func(config *config.AppConfig) {
+	},
+	SetupRepo: func(shell *Shell) {
+		shell.CreateDir("dir")
+		shell.CreateDir("dir/nested")
+		shell.CreateFileAndAdd("file1", "file1 content\n")
+		shell.CreateFileAndAdd("dir/file2", "file2 content\n")
+		shell.CreateFileAndAdd("dir/nested/file3", "file3 content\n")
+		shell.Commit("initial commit")
+		shell.RunCommand([]string{"git", "mv", "file1", "dir/file1"})
+		shell.RunCommand([]string{"git", "mv", "dir/file2", "dir/file2-renamed"})
+		shell.RunCommand([]string{"git", "mv", "dir/nested/file3", "file3"})
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Files().
+			IsFocused().
+			Lines(
+				Equals("▼ /"),
+				Equals("  ▼ dir"),
+				Equals("    R  file1 → file1"),
+				Equals("    R  file2 → file2-renamed"),
+				Equals("  R  dir/nested/file3 → file3"),
+			)
+	},
+})

pkg/integration/tests/test_list.go

@@ -195,6 +195,7 @@ var tests = []*components.IntegrationTest{
 	file.Gitignore,
 	file.RememberCommitMessageAfterFail,
 	file.RenameSimilarityThresholdChange,
+	file.RenamedFiles,
 	file.StageChildrenRangeSelect,
 	file.StageDeletedRangeSelect,
 	file.StageRangeSelect,