Honor the conflict-marker-size gitattribute

pkg/commands/git_commands/file_loader.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/jesseduffield/lazygit/pkg/commands/models"
 	"github.com/jesseduffield/lazygit/pkg/commands/oscommands"
+	"github.com/samber/lo"
 )
 
 type FileLoaderConfig interface {
@@ -88,6 +89,8 @@ func (self *FileLoader) GetStatusFiles(opts GetStatusFileOptions) []*models.File
 		files = append(files, file)
 	}
 
+	self.setConflictMarkerSizes(files)
+
 	// Go through the files to see if any of these files are actually worktrees
 	// so that we can render them correctly
 	worktreePaths := linkedWortkreePaths(self.Fs, self.repoPaths.RepoGitDirPath())
@@ -111,6 +114,63 @@ func (self *FileLoader) GetStatusFiles(opts GetStatusFileOptions) []*models.File
 	return files
 }
 
+// Looks up how long the conflict markers in the conflicted files are. We ask
+// git for all of them at once, because spawning a process per file would be
+// painfully slow when hundreds of files are conflicted (especially on Windows).
+func (self *FileLoader) setConflictMarkerSizes(files []*models.File) {
+	conflictedFiles := lo.Filter(files, func(file *models.File, _ int) bool {
+		return file.HasInlineMergeConflicts
+	})
+	if len(conflictedFiles) == 0 {
+		return
+	}
+
+	paths := lo.Map(conflictedFiles, func(file *models.File, _ int) string {
+		return file.Path
+	})
+
+	markerSizes, err := self.getConflictMarkerSizes(paths)
+	if err != nil {
+		self.Log.Error(err)
+		return
+	}
+
+	for _, file := range conflictedFiles {
+		file.ConflictMarkerSize = markerSizes[file.Path]
+	}
+}
+
+func (self *FileLoader) getConflictMarkerSizes(paths []string) (map[string]int, error) {
+	cmdArgs := NewGitCmd("check-attr").
+		Arg("-z").
+		Arg("--stdin").
+		Arg("conflict-marker-size").
+		ToArgv()
+
+	// -z makes git both read the paths and write its output NUL-separated, so
+	// that paths containing newlines don't throw us off.
+	output, _, err := self.cmd.New(cmdArgs).
+		SetStdin(strings.Join(paths, "\x00")).
+		DontLog().
+		RunWithOutputs()
+	if err != nil {
+		return nil, err
+	}
+
+	markerSizes := map[string]int{}
+	fields := strings.Split(output, "\x00")
+	// Each path yields a path/attribute/value triple; the value is either a
+	// number or something like "unspecified", in which case we leave the marker
+	// size at 0 to say that git's default applies.
+	for i := 0; i+2 < len(fields); i += 3 {
+		if markerSize, err := strconv.Atoi(fields[i+2]); err == nil && markerSize > 0 {
+			markerSizes[fields[i]] = markerSize
+		}
+	}
+
+	return markerSizes, nil
+}
+
 type FileDiff struct {
 	LinesAdded   int
 	LinesDeleted int

pkg/commands/git_commands/file_loader_test.go

@@ -37,6 +37,10 @@ func TestFileGetStatusFiles(t *testing.T) {
 				ExpectGitArgs([]string{"diff", "--numstat", "-z", "HEAD"},
 					"4\t1\tfile1.txt\x001\t0\tfile2.txt\x002\t2\tfile3.txt\x000\t2\tfile4.txt\x002\t2\tfile5.txt",
 					nil,
+				).
+				ExpectGitArgs([]string{"check-attr", "-z", "--stdin", "conflict-marker-size"},
+					"file5.txt\x00conflict-marker-size\x00unspecified\x00",
+					nil,
 				),
 			showNumstatInFilesView: true,
 			expectedFiles: []*models.File{
@@ -112,6 +116,58 @@ func TestFileGetStatusFiles(t *testing.T) {
 				},
 			},
 		},
+		{
+			testName:            "Conflicted files with a conflict-marker-size attribute",
+			similarityThreshold: 50,
+			runner: oscommands.NewFakeRunner(t).
+				ExpectGitArgs([]string{"status", "--untracked-files=yes", "--porcelain", "-z", "--find-renames=50%"},
+					"UU file1.txt\x00UU file2.txt\x00UU file3.txt\x00 M file4.txt",
+					nil,
+				).
+				ExpectGitArgs([]string{"check-attr", "-z", "--stdin", "conflict-marker-size"},
+					"file1.txt\x00conflict-marker-size\x0032\x00"+
+						"file2.txt\x00conflict-marker-size\x00unspecified\x00"+
+						"file3.txt\x00conflict-marker-size\x00nonsense\x00",
+					nil,
+				),
+			expectedFiles: []*models.File{
+				{
+					Path:                    "file1.txt",
+					HasUnstagedChanges:      true,
+					Tracked:                 true,
+					HasMergeConflicts:       true,
+					HasInlineMergeConflicts: true,
+					ConflictMarkerSize:      32,
+					DisplayString:           "UU file1.txt",
+					ShortStatus:             "UU",
+				},
+				{
+					Path:                    "file2.txt",
+					HasUnstagedChanges:      true,
+					Tracked:                 true,
+					HasMergeConflicts:       true,
+					HasInlineMergeConflicts: true,
+					DisplayString:           "UU file2.txt",
+					ShortStatus:             "UU",
+				},
+				{
+					Path:                    "file3.txt",
+					HasUnstagedChanges:      true,
+					Tracked:                 true,
+					HasMergeConflicts:       true,
+					HasInlineMergeConflicts: true,
+					DisplayString:           "UU file3.txt",
+					ShortStatus:             "UU",
+				},
+				{
+					Path:               "file4.txt",
+					HasUnstagedChanges: true,
+					Tracked:            true,
+					DisplayString:      " M file4.txt",
+					ShortStatus:        " M",
+				},
+			},
+		},
 		{
 			testName:            "File with new line char",
 			similarityThreshold: 50,

pkg/commands/models/file.go

@@ -18,10 +18,14 @@ type File struct {
 	Deleted                 bool
 	HasMergeConflicts       bool
 	HasInlineMergeConflicts bool
-	DisplayString           string
-	ShortStatus             string // e.g. 'AD', ' A', 'M ', '??'
-	LinesDeleted            int
-	LinesAdded              int
+	// How long the conflict markers in this file are, taken from its
+	// conflict-marker-size gitattribute; 0 if it doesn't have that attribute. We
+	// only look this up for files that have inline merge conflicts.
+	ConflictMarkerSize int
+	DisplayString      string
+	ShortStatus        string // e.g. 'AD', ' A', 'M ', '??'
+	LinesDeleted       int
+	LinesAdded         int
 
 	// If true, this must be a worktree folder
 	IsWorktree bool

pkg/gui/controllers/files_controller.go

@@ -328,7 +328,7 @@ func (self *FilesController) renderSubmoduleConflict(node *filetree.FileNode) {
 // (it was resolved in an editor), in which case the caller should fall back to
 // showing the file's diff.
 func (self *FilesController) renderInlineMergeConflict(node *filetree.FileNode) bool {
-	hasConflicts, err := self.c.Helpers().MergeConflicts.SetMergeState(node.GetPath())
+	hasConflicts, err := self.c.Helpers().MergeConflicts.SetMergeState(node.File)
 	if err != nil {
 		return true
 	}
@@ -1264,7 +1264,7 @@ func (self *FilesController) switchToMerge() error {
 		return nil
 	}
 
-	return self.c.Helpers().MergeConflicts.SwitchToMerge(file.Path)
+	return self.c.Helpers().MergeConflicts.SwitchToMerge(file)
 }
 
 func (self *FilesController) createStashMenu() error {

pkg/gui/controllers/helpers/merge_conflicts_helper.go

@@ -1,6 +1,7 @@
 package helpers
 
 import (
+	"github.com/jesseduffield/lazygit/pkg/commands/models"
 	"github.com/jesseduffield/lazygit/pkg/gui/context"
 	"github.com/jesseduffield/lazygit/pkg/gui/types"
 )
@@ -17,14 +18,14 @@ func NewMergeConflictsHelper(
 	}
 }
 
-func (self *MergeConflictsHelper) SetMergeState(path string) (bool, error) {
+func (self *MergeConflictsHelper) SetMergeState(file *models.File) (bool, error) {
 	self.context().GetMutex().Lock()
 	defer self.context().GetMutex().Unlock()
 
-	return self.setMergeStateWithoutLock(path)
+	return self.setMergeStateWithoutLock(file.Path, file.ConflictMarkerSize)
 }
 
-func (self *MergeConflictsHelper) setMergeStateWithoutLock(path string) (bool, error) {
+func (self *MergeConflictsHelper) setMergeStateWithoutLock(path string, markerSize int) (bool, error) {
 	content, err := self.c.Git().File.Cat(path)
 	if err != nil {
 		return false, err
@@ -34,7 +35,7 @@ func (self *MergeConflictsHelper) setMergeStateWithoutLock(path string) (bool, e
 		self.context().SetUserScrolling(false)
 	}
 
-	self.context().GetState().SetContent(content, path)
+	self.context().GetState().SetContent(content, path, markerSize)
 
 	return !self.context().GetState().NoConflicts(), nil
 }
@@ -72,7 +73,8 @@ func (self *MergeConflictsHelper) SetConflictsAndRender() (bool, error) {
 	self.context().GetMutex().Lock()
 	defer self.context().GetMutex().Unlock()
 
-	hasConflicts, err := self.setMergeStateWithoutLock(self.context().GetState().GetPath())
+	state := self.context().GetState()
+	hasConflicts, err := self.setMergeStateWithoutLock(state.GetPath(), state.GetMarkerSize())
 	if err != nil {
 		return false, err
 	}
@@ -84,9 +86,9 @@ func (self *MergeConflictsHelper) SetConflictsAndRender() (bool, error) {
 	return false, nil
 }
 
-func (self *MergeConflictsHelper) SwitchToMerge(path string) error {
-	if self.context().GetState().GetPath() != path {
-		hasConflicts, err := self.SetMergeState(path)
+func (self *MergeConflictsHelper) SwitchToMerge(file *models.File) error {
+	if self.context().GetState().GetPath() != file.Path {
+		hasConflicts, err := self.SetMergeState(file)
 		if err != nil {
 			return err
 		}

pkg/gui/controllers/helpers/refresh_helper.go

@@ -1305,7 +1305,8 @@ func (self *RefreshHelper) refreshStateFiles(captured capturedFilesState, env re
 				// process working directory, which may already point at another
 				// repo if the user switched while this refresh was in flight.
 				hasConflicts, err := mergeconflicts.FileHasConflictMarkers(
-					filepath.Join(env.git.RepoPaths.WorktreePath(), file.Path))
+					filepath.Join(env.git.RepoPaths.WorktreePath(), file.Path),
+					file.ConflictMarkerSize)
 				if err != nil {
 					self.c.Log.Error(err)
 				} else if !hasConflicts {

pkg/gui/filetree/file_node.go

@@ -51,7 +51,7 @@ func (self *FileNode) GetHasInlineMergeConflicts() bool {
 		if !file.HasInlineMergeConflicts {
 			return false
 		}
-		hasConflicts, _ := mergeconflicts.FileHasConflictMarkers(file.Path)
+		hasConflicts, _ := mergeconflicts.FileHasConflictMarkers(file.Path, file.ConflictMarkerSize)
 		return hasConflicts
 	})
 }