Fix and speed up the file list for the "Enter path to filter by" feature (#5056)

The file suggestions list that appears when you choose "Enter path to
filter by" from the Filtering menu was previously implemented by walking
the file system to collect all files, and then filter out the ones that
are git-ignored. This approach had several problems:
- for certain .gitignore configurations there was a bug in the code that
filters out ignored files, causing the list to be empty. See
#2642 (comment)
for details.
- the list included files from submodules. While at first glance this
might sound useful, it doesn't work: choosing a file from the list shows
an empty log. Lazygit would have to switch to the submodule first to
show the log, which would be unexpected in the context of the Filtering
dialog, so it's better to not show these files, and require the user to
enter a submodule explicitly before they can filter on a file in it.
- it was rather slow.

This PR improves all these by using a call to `git ls-files` to list the
repositories files.

Here are some rough hand-timed measurements (from opening the Filtering
dialog until the file list shows) for various repos:

|                             | before | after          |
|:--------------------------- | ------:| -------------- |
| lazygit (3'200 files)       |    ~1s | not measurable |
| my work repo (90'000 files) |     7s | <1s            |
| llvm (150'000 files)        |     5s | ~1s            |

Fixes #2642

Author: stefanhaller

go.mod

@@ -20,7 +20,6 @@ require (
 	github.com/jesseduffield/go-git/v5 v5.14.1-0.20250407170251-e1a013310ccd
 	github.com/jesseduffield/gocui v0.3.1-0.20251002151855-67e0e55ff42a
 	github.com/jesseduffield/lazycore v0.0.0-20221012050358-03d2e40243c5
-	github.com/jesseduffield/minimal/gitignore v0.3.3-0.20211018110810-9cde264e6b1e
 	github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0
 	github.com/karimkhaleel/jsonschema v0.0.0-20231001195015-d933f0d94ea3
 	github.com/kyokomi/emoji/v2 v2.2.8
@@ -60,7 +59,6 @@ require (
 	github.com/go-git/gcfg v1.5.1-0.20230307220236-3a3c6141e376 // indirect
 	github.com/go-git/go-billy/v5 v5.6.2 // indirect
 	github.com/go-logfmt/logfmt v0.5.0 // indirect
-	github.com/gobwas/glob v0.2.3 // indirect
 	github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8 // indirect
 	github.com/hpcloud/tail v1.0.0 // indirect
 	github.com/invopop/jsonschema v0.10.0 // indirect

go.sum

@@ -117,8 +117,6 @@ github.com/go-gl/glfw/v3.3/glfw v0.0.0-20200222043503-6f7a984d4dc4/go.mod h1:tQ2
 github.com/go-logfmt/logfmt v0.4.0/go.mod h1:3RMwSq7FuexP4Kalkev3ejPJsZTpXXBr9+V4qmtdjCk=
 github.com/go-logfmt/logfmt v0.5.0 h1:TrB8swr/68K7m9CcGut2g3UOihhbcbiMAYiuTXdEih4=
 github.com/go-logfmt/logfmt v0.5.0/go.mod h1:wCYkCAKZfumFQihp8CzCvQ3paCTfi41vtzG1KdI/P7A=
-github.com/gobwas/glob v0.2.3 h1:A4xDbljILXROh+kObIiy5kIaPYD8e96x1tgBhUI5J+Y=
-github.com/gobwas/glob v0.2.3/go.mod h1:d3Ez4x06l9bZtSvzIay5+Yzi0fmZzPgnTbPcKjJAkT8=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/groupcache v0.0.0-20190702054246-869f871628b6/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/groupcache v0.0.0-20191227052852-215e87163ea7/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
@@ -200,8 +198,6 @@ github.com/jesseduffield/gocui v0.3.1-0.20251002151855-67e0e55ff42a h1:z3NQvFXAW
 github.com/jesseduffield/gocui v0.3.1-0.20251002151855-67e0e55ff42a/go.mod h1:sLIyZ2J42R6idGdtemZzsiR3xY5EF0KsvYEGh3dQv3s=
 github.com/jesseduffield/lazycore v0.0.0-20221012050358-03d2e40243c5 h1:CDuQmfOjAtb1Gms6a1p5L2P8RhbLUq5t8aL7PiQd2uY=
 github.com/jesseduffield/lazycore v0.0.0-20221012050358-03d2e40243c5/go.mod h1:qxN4mHOAyeIDLP7IK7defgPClM/z1Kze8VVQiaEjzsQ=
-github.com/jesseduffield/minimal/gitignore v0.3.3-0.20211018110810-9cde264e6b1e h1:uw/oo+kg7t/oeMs6sqlAwr85ND/9cpO3up3VxphxY0U=
-github.com/jesseduffield/minimal/gitignore v0.3.3-0.20211018110810-9cde264e6b1e/go.mod h1:u60qdFGXRd36jyEXxetz0vQceQIxzI13lIo3EFUDf4I=
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1:6v2b51hI/fHJwM22ozAgKL4VKDeJcHhJFhtBdhmNjmU=
 github.com/jstemmer/go-junit-report v0.9.1/go.mod h1:Brl9GWCQeLvo8nXZwPNNblvFj/XSXhF0NWZEnDohbsk=

pkg/commands/git_commands/working_tree.go

@@ -451,3 +451,19 @@ func (self *WorkingTreeCommands) MergeFileForObjectIDs(strategy string, oursID s
 
 	return self.cmd.New(cmdArgs).RunWithOutput()
 }
+
+// Returns all tracked files in the repo (not in the working tree). The returned entries are
+// relative paths to the repo root, using '/' as the path separator on all platforms.
+// Does not really belong in WorkingTreeCommands, but it's close enough, and we don't seem to have a
+// better place for it right now.
+func (self *WorkingTreeCommands) AllRepoFiles() ([]string, error) {
+	cmdArgs := NewGitCmd("ls-files").Arg("-z").ToArgv()
+	output, err := self.cmd.New(cmdArgs).DontLog().RunWithOutput()
+	if err != nil {
+		return nil, err
+	}
+	if output == "" {
+		return []string{}, nil
+	}
+	return strings.Split(strings.TrimRight(output, "\x00"), "\x00"), nil
+}

pkg/commands/git_commands/working_tree_test.go

@@ -563,3 +563,32 @@ func TestWorkingTreeResetHard(t *testing.T) {
 		})
 	}
 }
+
+func TestWorkingTreeCommands_AllRepoFiles(t *testing.T) {
+	scenarios := []struct {
+		name     string
+		runner   *oscommands.FakeCmdObjRunner
+		expected []string
+	}{
+		{
+			name: "no files",
+			runner: oscommands.NewFakeRunner(t).
+				ExpectGitArgs([]string{"ls-files", "-z"}, "", nil),
+			expected: []string{},
+		},
+		{
+			name: "two files",
+			runner: oscommands.NewFakeRunner(t).
+				ExpectGitArgs([]string{"ls-files", "-z"}, "dir/file1.txt\x00dir2/file2.go\x00", nil),
+			expected: []string{"dir/file1.txt", "dir2/file2.go"},
+		},
+	}
+	for _, s := range scenarios {
+		t.Run(s.name, func(t *testing.T) {
+			instance := buildWorkingTreeCommands(commonDeps{runner: s.runner})
+			result, err := instance.AllRepoFiles()
+			assert.NoError(t, err)
+			assert.Equal(t, s.expected, result)
+		})
+	}
+}

pkg/gui/controllers/helpers/suggestions_helper.go

@@ -2,15 +2,14 @@ package helpers
 
 import (
 	"fmt"
-	"os"
 	"strings"
 
+	"github.com/jesseduffield/generics/set"
 	"github.com/jesseduffield/gocui"
 	"github.com/jesseduffield/lazygit/pkg/commands/models"
 	"github.com/jesseduffield/lazygit/pkg/gui/presentation"
 	"github.com/jesseduffield/lazygit/pkg/gui/types"
 	"github.com/jesseduffield/lazygit/pkg/utils"
-	"github.com/jesseduffield/minimal/gitignore"
 	"github.com/samber/lo"
 	"golang.org/x/exp/slices"
 	"gopkg.in/ozeidan/fuzzy-patricia.v3/patricia"
@@ -92,22 +91,28 @@ func (self *SuggestionsHelper) GetBranchNameSuggestionsFunc() func(string) []*ty
 func (self *SuggestionsHelper) GetFilePathSuggestionsFunc() func(string) []*types.Suggestion {
 	_ = self.c.WithWaitingStatus(self.c.Tr.LoadingFileSuggestions, func(gocui.Task) error {
 		trie := patricia.NewTrie()
-		// load every non-gitignored file in the repo
-		ignore, err := gitignore.FromGit()
+
+		// load every file in the repo
+		files, err := self.c.Git().WorkingTree.AllRepoFiles()
 		if err != nil {
 			return err
 		}
 
-		err = ignore.Walk(".",
-			func(path string, info os.FileInfo, err error) error {
-				if err != nil {
-					return err
-				}
-				if path != "." {
-					trie.Insert(patricia.Prefix(path), path)
+		seen := set.New[string]()
+		for _, file := range files {
+			// For every file we also want to add its parent directories, but only once.
+			for i := range len(file) {
+				if file[i] == '/' {
+					dir := file[:i]
+					if !seen.Includes(dir) {
+						trie.Insert(patricia.Prefix(dir), dir)
+						seen.Add(dir)
+					}
 				}
-				return nil
-			})
+			}
+
+			trie.Insert(patricia.Prefix(file), file)
+		}
 
 		// cache the trie for future use
 		self.c.Model().FilesTrie = trie