Add merge menu with conflict resolver

docs/Config.md

@@ -619,7 +619,7 @@ keybinding:
     viewResetOptions: D
     fetch: f
     toggleTreeView: '`'
-    openMergeTool: M
+    openMergeOptions: M
     openStatusFilter: <c-b>
     copyFileInfoToClipboard: "y"
     collapseAll: '-'

docs/keybindings/Keybindings_en.md

@@ -153,7 +153,7 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` D `` | Reset | View reset options for working tree (e.g. nuking the working tree). |
 | `` ` `` | Toggle file tree view | Toggle file view between flat and tree layout. Flat layout shows all file paths in a single list, tree layout groups files by directory.<br><br>The default can be changed in the config file with the key 'gui.showFileTree'. |
 | `` <c-t> `` | Open external diff tool (git difftool) |  |
-| `` M `` | Open external merge tool | Run `git mergetool`. |
+| `` M `` | View merge conflict options | View options for resolving merge conflicts. |
 | `` f `` | Fetch | Fetch changes from remote. |
 | `` - `` | Collapse all files | Collapse all directories in the files tree |
 | `` = `` | Expand all files | Expand all directories in the file tree |

docs/keybindings/Keybindings_ja.md

@@ -235,7 +235,7 @@ _凡例：`＜c-b＞` はctrl+b、`＜a-b＞` はalt+b、`B` はshift+bを意味
 | `` D `` | リセット | 作業ツリーのリセットオプション（例：作業ツリーの完全破棄）を表示します。 |
 | `` ` `` | ファイルツリービューを切り替え | Toggle file view between flat and tree layout. Flat layout shows all file paths in a single list, tree layout groups files by directory.<br><br>The default can be changed in the config file with the key 'gui.showFileTree'. |
 | `` <c-t> `` | 外部差分ツールを開く（git difftool） |  |
-| `` M `` | 外部マージツールを開く | `git mergetool`を実行します。 |
+| `` M `` | View merge conflict options | View options for resolving merge conflicts. |
 | `` f `` | フェッチ | リモートから変更をフェッチします。 |
 | `` - `` | すべてのファイルを折りたたむ | ファイルツリー内のすべてのディレクトリを折りたたみます |
 | `` = `` | すべてのファイルを展開 | ファイルツリー内のすべてのディレクトリを展開します |

docs/keybindings/Keybindings_ko.md

@@ -396,7 +396,7 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` D `` | 초기화 | View reset options for working tree (e.g. nuking the working tree). |
 | `` ` `` | 파일 트리뷰로 전환 | Toggle file view between flat and tree layout. Flat layout shows all file paths in a single list, tree layout groups files by directory.<br><br>The default can be changed in the config file with the key 'gui.showFileTree'. |
 | `` <c-t> `` | Open external diff tool (git difftool) |  |
-| `` M `` | Git mergetool를 열기 | Run `git mergetool`. |
+| `` M `` | View merge conflict options | View options for resolving merge conflicts. |
 | `` f `` | Fetch | Fetch changes from remote. |
 | `` - `` | Collapse all files | Collapse all directories in the files tree |
 | `` = `` | Expand all files | Expand all directories in the file tree |

docs/keybindings/Keybindings_nl.md

@@ -78,7 +78,7 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` D `` | Reset | View reset options for working tree (e.g. nuking the working tree). |
 | `` ` `` | Toggle bestandsboom weergave | Toggle file view between flat and tree layout. Flat layout shows all file paths in a single list, tree layout groups files by directory.<br><br>The default can be changed in the config file with the key 'gui.showFileTree'. |
 | `` <c-t> `` | Open external diff tool (git difftool) |  |
-| `` M `` | Open external merge tool | Run `git mergetool`. |
+| `` M `` | View merge conflict options | View options for resolving merge conflicts. |
 | `` f `` | Fetch | Fetch changes from remote. |
 | `` - `` | Collapse all files | Collapse all directories in the files tree |
 | `` = `` | Expand all files | Expand all directories in the file tree |

docs/keybindings/Keybindings_pl.md

@@ -252,7 +252,7 @@ _Legenda: `<c-b>` oznacza ctrl+b, `<a-b>` oznacza alt+b, `B` oznacza shift+b_
 | `` D `` | Reset | Wyświetl opcje resetu dla drzewa roboczego (np. zniszczenie drzewa roboczego). |
 | `` ` `` | Przełącz widok drzewa plików | Toggle file view between flat and tree layout. Flat layout shows all file paths in a single list, tree layout groups files by directory.<br><br>The default can be changed in the config file with the key 'gui.showFileTree'. |
 | `` <c-t> `` | Otwórz zewnętrzne narzędzie różnic (git difftool) |  |
-| `` M `` | Otwórz zewnętrzne narzędzie scalania | Uruchom `git mergetool`. |
+| `` M `` | View merge conflict options | View options for resolving merge conflicts. |
 | `` f `` | Pobierz | Pobierz zmiany ze zdalnego serwera. |
 | `` - `` | Collapse all files | Collapse all directories in the files tree |
 | `` = `` | Expand all files | Expand all directories in the file tree |

docs/keybindings/Keybindings_pt.md

@@ -78,7 +78,7 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` D `` | Restaurar | Opções de redefinição de exibição para árvore de trabalho (por exemplo, nukando a árvore de trabalho). |
 | `` ` `` | Alternar exibição de árvore de arquivo | Toggle file view between flat and tree layout. Flat layout shows all file paths in a single list, tree layout groups files by directory.<br><br>The default can be changed in the config file with the key 'gui.showFileTree'. |
 | `` <c-t> `` | Abrir ferramenta de diff externa (git difftool) |  |
-| `` M `` | Abrir ferramenta de merge externa | Execute `git mergetool`. |
+| `` M `` | View merge conflict options | View options for resolving merge conflicts. |
 | `` f `` | Buscar | Buscar alterações do controle remoto. |
 | `` - `` | Recolher todos os arquivos | Recolher todos os diretórios na árvore de arquivos |
 | `` = `` | Expandir todos os arquivos | Expandir todos os diretórios na árvore do arquivo |

docs/keybindings/Keybindings_ru.md

@@ -390,7 +390,7 @@ _Связки клавиш_
 | `` D `` | Reset | View reset options for working tree (e.g. nuking the working tree). |
 | `` ` `` | Переключить вид дерева файлов | Toggle file view between flat and tree layout. Flat layout shows all file paths in a single list, tree layout groups files by directory.<br><br>The default can be changed in the config file with the key 'gui.showFileTree'. |
 | `` <c-t> `` | Open external diff tool (git difftool) |  |
-| `` M `` | Открыть внешний инструмент слияния (git mergetool) | Run `git mergetool`. |
+| `` M `` | View merge conflict options | View options for resolving merge conflicts. |
 | `` f `` | Получить изменения | Fetch changes from remote. |
 | `` - `` | Collapse all files | Collapse all directories in the files tree |
 | `` = `` | Expand all files | Expand all directories in the file tree |

docs/keybindings/Keybindings_zh-CN.md

@@ -216,7 +216,7 @@ _图例：`<c-b>` 意味着ctrl+b, `<a-b>意味着Alt+b, `B` 意味着shift+b_
 | `` D `` | 重置 | 查看工作树的重置选项（例如：清除工作树）。 |
 | `` ` `` | 切换文件树视图 | Toggle file view between flat and tree layout. Flat layout shows all file paths in a single list, tree layout groups files by directory.<br><br>The default can be changed in the config file with the key 'gui.showFileTree'. |
 | `` <c-t> `` | 使用外部差异比较工具(git difftool) |  |
-| `` M `` | 打开外部合并工具(git mergetool) | 执行 `git mergetool`. |
+| `` M `` | View merge conflict options | View options for resolving merge conflicts. |
 | `` f `` | 抓取 | 从远程获取变更 |
 | `` - `` | 折叠全部文件 | 折叠文件树中的全部目录 |
 | `` = `` | 展开全部文件 | 展开文件树中的全部目录 |

docs/keybindings/Keybindings_zh-TW.md

@@ -347,7 +347,7 @@ _說明：`<c-b>` 表示 Ctrl＋B、`<a-b>` 表示 Alt＋B，`B`表示 Shift＋B
 | `` D `` | 重設 | View reset options for working tree (e.g. nuking the working tree). |
 | `` ` `` | 顯示檔案樹狀視圖 | Toggle file view between flat and tree layout. Flat layout shows all file paths in a single list, tree layout groups files by directory.<br><br>The default can be changed in the config file with the key 'gui.showFileTree'. |
 | `` <c-t> `` | 開啟外部差異工具 (git difftool) |  |
-| `` M `` | 開啟外部合併工具 | 執行 `git mergetool`。 |
+| `` M `` | View merge conflict options | View options for resolving merge conflicts. |
 | `` f `` | 擷取 | 同步遠端異動 |
 | `` - `` | Collapse all files | Collapse all directories in the files tree |
 | `` = `` | Expand all files | Expand all directories in the file tree |

pkg/commands/git_commands/working_tree.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"path/filepath"
 	"regexp"
+	"strings"
 
 	"github.com/go-errors/errors"
 	"github.com/jesseduffield/lazygit/pkg/commands/models"
@@ -407,3 +408,26 @@ func (self *WorkingTreeCommands) ResetMixed(ref string) error {
 
 	return self.cmd.New(cmdArgs).Run()
 }
+
+func (self *WorkingTreeCommands) ObjectIDAtStage(path string, stage int) (string, error) {
+	cmdArgs := NewGitCmd("rev-parse").
+		Arg(fmt.Sprintf(":%d:%s", stage, path)).
+		ToArgv()
+
+	output, err := self.cmd.New(cmdArgs).RunWithOutput()
+	if err != nil {
+		return "", err
+	}
+
+	return strings.TrimSpace(output), nil
+}
+
+func (self *WorkingTreeCommands) MergeFile(strategy string, oursID string, baseID string, theirsID string) (string, error) {
+	cmdArgs := NewGitCmd("merge-file").
+		Arg("--object-id").
+		Arg(strategy).
+		Arg("-p", oursID, baseID, theirsID).
+		ToArgv()
+
+	return self.cmd.New(cmdArgs).RunWithOutput()
+}

pkg/config/app_config_test.go

@@ -897,7 +897,7 @@ keybinding:
     toggleStagedAll: a
     viewResetOptions: D
     fetch: f
-    openMergeTool: M
+    openMergeOptions: M
     openStatusFilter: <c-b>
     copyFileInfoToClipboard: "y"
     collapseAll: '-'

pkg/config/user_config.go

@@ -487,7 +487,7 @@ type KeybindingFilesConfig struct {
 	ViewResetOptions         string `yaml:"viewResetOptions"`
 	Fetch                    string `yaml:"fetch"`
 	ToggleTreeView           string `yaml:"toggleTreeView"`
-	OpenMergeTool            string `yaml:"openMergeTool"`
+	OpenMergeOptions         string `yaml:"openMergeOptions"`
 	OpenStatusFilter         string `yaml:"openStatusFilter"`
 	CopyFileInfoToClipboard  string `yaml:"copyFileInfoToClipboard"`
 	CollapseAll              string `yaml:"collapseAll"`
@@ -950,7 +950,7 @@ func GetDefaultConfig() *UserConfig {
 				ViewResetOptions:         "D",
 				Fetch:                    "f",
 				ToggleTreeView:           "`",
-				OpenMergeTool:            "M",
+				OpenMergeOptions:         "M",
 				OpenStatusFilter:         "<c-b>",
 				ConfirmDiscard:           "x",
 				CopyFileInfoToClipboard:  "y",

pkg/gui/command_log_panel.go

@@ -124,8 +124,8 @@ func (gui *Gui) getRandomTip() string {
 			formattedKey(config.Universal.Remove),
 		),
 		fmt.Sprintf(
-			"If you need to pull out the big guns to resolve merge conflicts, you can press '%s' in the files panel to open 'git mergetool'",
-			formattedKey(config.Files.OpenMergeTool),
+			"If you need to pull out the big guns to resolve merge conflicts, you can press '%s' in the files panel to open merge options",
+			formattedKey(config.Files.OpenMergeOptions),
 		),
 		fmt.Sprintf(
 			"To revert a commit, press '%s' on that commit",

pkg/gui/controllers/files_controller.go

@@ -3,6 +3,7 @@ package controllers
 import (
 	"errors"
 	"fmt"
+	"os"
 	"path/filepath"
 	"strings"
 
@@ -12,6 +13,7 @@ import (
 	"github.com/jesseduffield/lazygit/pkg/commands/models"
 	"github.com/jesseduffield/lazygit/pkg/gui/context"
 	"github.com/jesseduffield/lazygit/pkg/gui/filetree"
+	"github.com/jesseduffield/lazygit/pkg/gui/style"
 	"github.com/jesseduffield/lazygit/pkg/gui/types"
 	"github.com/jesseduffield/lazygit/pkg/utils"
 	"github.com/samber/lo"
@@ -178,10 +180,12 @@ func (self *FilesController) GetKeybindings(opts types.KeybindingsOpts) []*types
 			Description:       self.c.Tr.OpenDiffTool,
 		},
 		{
-			Key:         opts.GetKey(opts.Config.Files.OpenMergeTool),
-			Handler:     self.c.Helpers().WorkingTree.OpenMergeTool,
-			Description: self.c.Tr.OpenMergeTool,
-			Tooltip:     self.c.Tr.OpenMergeToolTooltip,
+			Key:             opts.GetKey(opts.Config.Files.OpenMergeOptions),
+			Handler:         self.withItems(self.createMergeConflictMenu),
+			Description:     self.c.Tr.ViewMergeConflictOptions,
+			Tooltip:         self.c.Tr.ViewMergeConflictOptionsTooltip,
+			OpensMenu:       true,
+			DisplayOnScreen: true,
 		},
 		{
 			Key:         opts.GetKey(opts.Config.Files.Fetch),
@@ -1024,6 +1028,92 @@ func (self *FilesController) createStashMenu() error {
 	})
 }
 
+func (self *FilesController) createMergeConflictMenu(nodes []*filetree.FileNode) error {
+	onMergeStrategySelected := func(strategy string) error {
+		normalizedNodes := normalisedSelectedNodes(nodes)
+		fileNodes := lo.Filter(normalizedNodes, func(node *filetree.FileNode, _ int) bool {
+			return node.File != nil
+		})
+		filenames := lo.Map(fileNodes, func(node *filetree.FileNode, _ int) string {
+			return node.GetPath()
+		})
+
+		for _, filename := range filenames {
+			baseID, err := self.c.Git().WorkingTree.ObjectIDAtStage(filename, 1)
+			if err != nil {
+				return err
+			}
+
+			oursID, err := self.c.Git().WorkingTree.ObjectIDAtStage(filename, 2)
+			if err != nil {
+				return err
+			}
+
+			theirsID, err := self.c.Git().WorkingTree.ObjectIDAtStage(filename, 3)
+			if err != nil {
+				return err
+			}
+
+			output, err := self.c.Git().WorkingTree.MergeFile(strategy, oursID, baseID, theirsID)
+			if err != nil {
+				return err
+			}
+
+			if err = os.WriteFile(filename, []byte(output), 0o644); err != nil {
+				return err
+			}
+		}
+
+		err := self.c.Git().WorkingTree.StageFiles(filenames, nil)
+		return self.c.Helpers().MergeAndRebase.CheckMergeOrRebase(err)
+	}
+
+	cmdColor := style.FgBlue
+	return self.c.Menu(types.CreateMenuOptions{
+		Title: self.c.Tr.MergeConflictOptionsTitle,
+		Items: []*types.MenuItem{
+			{
+				LabelColumns: []string{
+					self.c.Tr.UseHead,
+					cmdColor.Sprint("git merge-file --ours"),
+				},
+				OnPress: func() error {
+					return onMergeStrategySelected("--ours")
+				},
+				Key: 'h',
+			},
+			{
+				LabelColumns: []string{
+					self.c.Tr.UseIncoming,
+					cmdColor.Sprint("git merge-file --theirs"),
+				},
+				OnPress: func() error {
+					return onMergeStrategySelected("--theirs")
+				},
+				Key: 'i',
+			},
+			{
+				LabelColumns: []string{
+					self.c.Tr.UseBoth,
+					cmdColor.Sprint("git merge-file --union"),
+				},
+				OnPress: func() error {
+					return onMergeStrategySelected("--union")
+				},
+				Key: 'b',
+			},
+			{
+				LabelColumns: []string{
+					self.c.Tr.OpenMergeTool,
+					cmdColor.Sprint("git mergetool"),
+				},
+				OnPress: self.c.Helpers().WorkingTree.OpenMergeTool,
+				Key:     'm',
+			},
+		},
+	})
+}
+
 func (self *FilesController) openCopyMenu() error {
 	node := self.context().GetSelected()
 

pkg/gui/controllers/merge_conflicts_controller.go

@@ -112,7 +112,7 @@ func (self *MergeConflictsController) GetKeybindings(opts types.KeybindingsOpts)
 			Tag:         "navigation",
 		},
 		{
-			Key:             opts.GetKey(opts.Config.Files.OpenMergeTool),
+			Key:             opts.GetKey(opts.Config.Files.OpenMergeOptions),
 			Handler:         self.c.Helpers().WorkingTree.OpenMergeTool,
 			Description:     self.c.Tr.OpenMergeTool,
 			Tooltip:         self.c.Tr.OpenMergeToolTooltip,

pkg/i18n/english.go

@@ -898,8 +898,13 @@ type TranslationSet struct {
 	BreakingChangesTitle                     string
 	BreakingChangesMessage                   string
 	BreakingChangesByVersion                 map[string]string
+	ViewMergeConflictOptions                 string
+	ViewMergeConflictOptionsTooltip          string
+	MergeConflictOptionsTitle                string
+	UseHead                                  string
+	UseIncoming                              string
+	UseBoth                                  string
 }
-
 type Bisect struct {
 	MarkStart                   string
 	ResetTitle                  string
@@ -1970,6 +1975,12 @@ func EnglishTranslationSet() *TranslationSet {
 		CustomCommands:                           "Custom commands",
 		NoApplicableCommandsInThisContext:        "(No applicable commands in this context)",
 		SelectCommitsOfCurrentBranch:             "Select commits of current branch",
+		ViewMergeConflictOptions:                 "View merge conflict options",
+		ViewMergeConflictOptionsTooltip:          "View options for resolving merge conflicts.",
+		MergeConflictOptionsTitle:                "Resolve merge conflicts",
+		UseHead:                                  "Use HEAD",
+		UseIncoming:                              "Use Incoming",
+		UseBoth:                                  "Use Both",
 
 		Actions: Actions{
 			// TODO: combine this with the original keybinding descriptions (those are all in lowercase atm)