Don't include common ancestor when picking "both" for a conflict in diff3 style (#5747)

When a merge conflict is rendered in the diff3 style, git includes the
common-ancestor section between the two sides. Pressing `b` used to pick
all three, which doesn't make sense; it now picks only the current and
incoming hunks.

Fixes #5486.

docs-master/keybindings/Keybindings_en.md

@@ -205,7 +205,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | Key | Action | Info |
 |-----|--------|-------------|
 | `` <space> `` | Pick hunk |  |
-| `` b `` | Pick all hunks |  |
+| `` b `` | Pick both hunks |  |
 | `` <up>, k `` | Previous hunk |  |
 | `` <down>, j `` | Next hunk |  |
 | `` <left>, h `` | Previous conflict |  |

docs-master/keybindings/Keybindings_ja.md

@@ -287,7 +287,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | Key | Action | Info |
 |-----|--------|-------------|
 | `` <space> `` | ハンクを選択 |  |
-| `` b `` | すべてのハンクを選択 |  |
+| `` b `` | Pick both hunks |  |
 | `` <up>, k `` | 前のハンク |  |
 | `` <down>, j `` | 次のハンク |  |
 | `` <left>, h `` | 前のコンフリクト |  |

docs-master/keybindings/Keybindings_ko.md

@@ -144,7 +144,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | Key | Action | Info |
 |-----|--------|-------------|
 | `` <space> `` | Pick hunk |  |
-| `` b `` | Pick all hunks |  |
+| `` b `` | Pick both hunks |  |
 | `` <up>, k `` | 이전 hunk를 선택 |  |
 | `` <down>, j `` | 다음 hunk를 선택 |  |
 | `` <left>, h `` | 이전 충돌을 선택 |  |

docs-master/keybindings/Keybindings_nl.md

@@ -213,7 +213,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | Key | Action | Info |
 |-----|--------|-------------|
 | `` <space> `` | Kies stuk |  |
-| `` b `` | Kies beide stukken |  |
+| `` b `` | Pick both hunks |  |
 | `` <up>, k `` | Selecteer bovenste hunk |  |
 | `` <down>, j `` | Selecteer onderste hunk |  |
 | `` <left>, h `` | Selecteer voorgaand conflict |  |

docs-master/keybindings/Keybindings_pl.md

@@ -209,7 +209,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | Key | Action | Info |
 |-----|--------|-------------|
 | `` <space> `` | Wybierz fragment |  |
-| `` b `` | Wybierz wszystkie fragmenty |  |
+| `` b `` | Pick both hunks |  |
 | `` <up>, k `` | Poprzedni fragment |  |
 | `` <down>, j `` | Następny fragment |  |
 | `` <left>, h `` | Poprzedni konflikt |  |

docs-master/keybindings/Keybindings_pt.md

@@ -273,7 +273,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | Key | Action | Info |
 |-----|--------|-------------|
 | `` <space> `` | Escolha o local |  |
-| `` b `` | Pegar todos os pedaços |  |
+| `` b `` | Pick both hunks |  |
 | `` <up>, k `` | Trecho anterior |  |
 | `` <down>, j `` | Próximo trecho |  |
 | `` <left>, h `` | Conflito anterior |  |

docs-master/keybindings/Keybindings_ru.md

@@ -114,7 +114,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | Key | Action | Info |
 |-----|--------|-------------|
 | `` <space> `` | Выбрать эту часть |  |
-| `` b `` | Выбрать все части |  |
+| `` b `` | Pick both hunks |  |
 | `` <up>, k `` | Выбрать предыдущую часть |  |
 | `` <down>, j `` | Выбрать следующую часть |  |
 | `` <left>, h `` | Выбрать предыдущий конфликт |  |

docs-master/keybindings/Keybindings_zh-CN.md

@@ -294,7 +294,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | Key | Action | Info |
 |-----|--------|-------------|
 | `` <space> `` | 选中区块 |  |
-| `` b `` | 选中所有区块 |  |
+| `` b `` | Pick both hunks |  |
 | `` <up>, k `` | 选择顶部块 |  |
 | `` <down>, j `` | 选择底部块 |  |
 | `` <left>, h `` | 选择上一个冲突 |  |

docs-master/keybindings/Keybindings_zh-TW.md

@@ -90,7 +90,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | Key | Action | Info |
 |-----|--------|-------------|
 | `` <space> `` | 挑選程式碼片段 |  |
-| `` b `` | 挑選所有程式碼片段 |  |
+| `` b `` | Pick both hunks |  |
 | `` <up>, k `` | 選擇上一段 |  |
 | `` <down>, j `` | 選擇下一段 |  |
 | `` <left>, h `` | 選擇上一個衝突 |  |

pkg/gui/controllers/merge_conflicts_controller.go

@@ -35,8 +35,8 @@ func (self *MergeConflictsController) GetKeybindings(opts types.KeybindingsOpts)
 		},
 		{
 			Keys:            opts.GetKeys(opts.Config.Main.PickBothHunks),
-			Handler:         self.withRenderAndFocus(self.HandlePickAllHunks),
-			Description:     self.c.Tr.PickAllHunks,
+			Handler:         self.withRenderAndFocus(self.HandlePickBothHunks),
+			Description:     self.c.Tr.PickBothHunks,
 			DisplayOnScreen: true,
 		},
 		{
@@ -247,8 +247,8 @@ func (self *MergeConflictsController) HandlePickHunk() error {
 	return self.pickSelection(self.context().GetState().Selection())
 }
 
-func (self *MergeConflictsController) HandlePickAllHunks() error {
-	return self.pickSelection(mergeconflicts.ALL)
+func (self *MergeConflictsController) HandlePickBothHunks() error {
+	return self.pickSelection(mergeconflicts.BOTH)
 }
 
 func (self *MergeConflictsController) pickSelection(selection mergeconflicts.Selection) error {
@@ -290,8 +290,8 @@ func (self *MergeConflictsController) resolveConflict(selection mergeconflicts.S
 		logStr = "Picking middle hunk"
 	case mergeconflicts.BOTTOM:
 		logStr = "Picking bottom hunk"
-	case mergeconflicts.ALL:
-		logStr = "Picking all hunks"
+	case mergeconflicts.BOTH:
+		logStr = "Picking both hunks"
 	}
 	self.c.LogAction("Resolve merge conflict")
 	self.c.LogCommand(logStr, false)

pkg/gui/mergeconflicts/merge_conflict.go

@@ -28,7 +28,7 @@ const (
 	TOP Selection = iota
 	MIDDLE
 	BOTTOM
-	ALL
+	BOTH
 )
 
 func (s Selection) isIndexToKeep(conflict *mergeConflict, i int) bool {
@@ -56,14 +56,23 @@ func (s Selection) bounds(c *mergeConflict) (int, int) {
 		return c.ancestor, c.target
 	case BOTTOM:
 		return c.target, c.end
-	case ALL:
-		return c.start, c.end
+	case BOTH:
+		// BOTH spans two disjoint hunks, so it has no single range; callers
+		// go through selected() instead of asking for its bounds.
+		panic("BOTH has no single range")
 	}
 
 	panic("unexpected selection for merge conflict")
 }
 
 func (s Selection) selected(c *mergeConflict, idx int) bool {
+	// BOTH keeps the top and bottom hunks but drops the common ancestor in
+	// between (which is only present with the diff3 conflict style), so it
+	// isn't a single contiguous range like the other selections.
+	if s == BOTH {
+		return TOP.selected(c, idx) || BOTTOM.selected(c, idx)
+	}
+
 	start, end := s.bounds(c)
 	return start < idx && idx < end
 }

pkg/i18n/english.go

@@ -320,7 +320,7 @@ type TranslationSet struct {
 	ViewConflictsMenuItem                 string
 	AbortMenuItem                         string
 	PickHunk                              string
-	PickAllHunks                          string
+	PickBothHunks                         string
 	ViewMergeRebaseOptions                string
 	ViewMergeRebaseOptionsTooltip         string
 	ViewMergeOptions                      string
@@ -1338,7 +1338,7 @@ func EnglishTranslationSet() *TranslationSet {
 		RewordCommitEditor:                   "Reword with editor",
 		Error:                                "Error",
 		PickHunk:                             "Pick hunk",
-		PickAllHunks:                         "Pick all hunks",
+		PickBothHunks:                        "Pick both hunks",
 		Undo:                                 "Undo",
 		UndoReflog:                           "Undo",
 		RedoReflog:                           "Redo",

pkg/integration/tests/conflicts/pick_both_hunks_diff3.go

@@ -0,0 +1,41 @@
+package conflicts
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+	"github.com/jesseduffield/lazygit/pkg/integration/tests/shared"
+)
+
+var PickBothHunksDiff3 = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Pick both hunks of a conflict rendered in the diff3 style; the common ancestor must not be included",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shell.SetConfig("merge.conflictStyle", "diff3")
+		shared.CreateMergeConflictFile(shell)
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Files().
+			IsFocused().
+			Lines(
+				Contains("UU file").IsSelected(),
+			).
+			PressEnter()
+
+		t.Views().MergeConflicts().
+			IsFocused().
+			// the diff3 style renders the common ancestor between the two changes
+			Content(Contains("<<<<<<< HEAD\nFirst Change")).
+			Content(Contains("||||||| ")).
+			Content(Contains("Original")).
+			Press(keys.Main.PickBothHunks)
+
+		t.Common().ContinueOnConflictsResolved("merge")
+
+		t.Views().Files().IsEmpty()
+
+		t.FileSystem().FileContent("file",
+			Equals("\nThis\nIs\nThe\nFirst Change\nSecond Change\nFile\n"))
+	},
+})

pkg/integration/tests/test_list.go

@@ -167,6 +167,7 @@ var tests = []*components.IntegrationTest{
 	conflicts.MergeFileBoth,
 	conflicts.MergeFileCurrent,
 	conflicts.MergeFileIncoming,
+	conflicts.PickBothHunksDiff3,
 	conflicts.ResolveExternally,
 	conflicts.ResolveMultipleFiles,
 	conflicts.ResolveNoAutoStage,