Allow removing lines from patch directly

I always press 'd' in the patch building view, expecting that I can do
exactly what I can do in the staging view, to find out I need to go
space -> ctrl+p -> d and I think it's time to honour the muscle memory
and support this convenience keybinding.

Author: jesseduffield

docs-master/keybindings/Keybindings_en.md

@@ -237,6 +237,7 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` o `` | Open file | Open file in default application. |
 | `` e `` | Edit file | Open file in external editor. |
 | `` <space> `` | Toggle lines in patch |  |
+| `` d `` | Remove lines from commit | Remove the selected lines from this commit. This runs an interactive rebase in the background, so you may get a merge conflict if a later commit also changes these lines. |
 | `` <esc> `` | Exit custom patch builder |  |
 | `` / `` | Search the current view by text |  |
 

docs-master/keybindings/Keybindings_ja.md

@@ -278,6 +278,7 @@ _凡例：`＜c-b＞` はctrl+b、`＜a-b＞` はalt+b、`B` はshift+bを意味
 | `` o `` | ファイルを開く | デフォルトのアプリケーションでファイルを開きます。 |
 | `` e `` | ファイルを編集 | 外部エディタでファイルを開きます。 |
 | `` <space> `` | パッチ内の行を切り替え |  |
+| `` d `` | Remove lines from commit | Remove the selected lines from this commit. This runs an interactive rebase in the background, so you may get a merge conflict if a later commit also changes these lines. |
 | `` <esc> `` | カスタムパッチビルダーを終了 |  |
 | `` / `` | 現在のビューをテキストで検索 |  |
 

docs-master/keybindings/Keybindings_ko.md

@@ -178,6 +178,7 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` o `` | 파일 닫기 | Open file in default application. |
 | `` e `` | 파일 편집 | Open file in external editor. |
 | `` <space> `` | Line(s)을 패치에 추가/삭제 |  |
+| `` d `` | Remove lines from commit | Remove the selected lines from this commit. This runs an interactive rebase in the background, so you may get a merge conflict if a later commit also changes these lines. |
 | `` <esc> `` | Exit custom patch builder |  |
 | `` / `` | 검색 시작 |  |
 

docs-master/keybindings/Keybindings_nl.md

@@ -245,6 +245,7 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` o `` | Open bestand | Open file in default application. |
 | `` e `` | Verander bestand | Open file in external editor. |
 | `` <space> `` | Voeg toe/verwijder lijn(en) in patch |  |
+| `` d `` | Remove lines from commit | Remove the selected lines from this commit. This runs an interactive rebase in the background, so you may get a merge conflict if a later commit also changes these lines. |
 | `` <esc> `` | Sluit lijn-bij-lijn modus |  |
 | `` / `` | Start met zoeken |  |
 

docs-master/keybindings/Keybindings_pl.md

@@ -124,6 +124,7 @@ _Legenda: `<c-b>` oznacza ctrl+b, `<a-b>` oznacza alt+b, `B` oznacza shift+b_
 | `` o `` | Otwórz plik | Otwórz plik w domyślnej aplikacji. |
 | `` e `` | Edytuj plik | Otwórz plik w zewnętrznym edytorze. |
 | `` <space> `` | Przełącz linie w łatce |  |
+| `` d `` | Remove lines from commit | Remove the selected lines from this commit. This runs an interactive rebase in the background, so you may get a merge conflict if a later commit also changes these lines. |
 | `` <esc> `` | Wyjdź z budowniczego niestandardowej łatki |  |
 | `` / `` | Szukaj w bieżącym widoku po tekście |  |
 

docs-master/keybindings/Keybindings_pt.md

@@ -295,6 +295,7 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` o `` | Abrir arquivo | Abrir arquivo no aplicativo padrão. |
 | `` e `` | Editar arquivo | Abrir arquivo no editor externo. |
 | `` <space> `` | Alternar linhas no caminho |  |
+| `` d `` | Remove lines from commit | Remove the selected lines from this commit. This runs an interactive rebase in the background, so you may get a merge conflict if a later commit also changes these lines. |
 | `` <esc> `` | Sair do construtor de patch personalizado |  |
 | `` / `` | Search the current view by text |  |
 

docs-master/keybindings/Keybindings_ru.md

@@ -138,6 +138,7 @@ _Связки клавиш_
 | `` o `` | Открыть файл | Open file in default application. |
 | `` e `` | Редактировать файл | Open file in external editor. |
 | `` <space> `` | Добавить/удалить строку(и) для патча |  |
+| `` d `` | Remove lines from commit | Remove the selected lines from this commit. This runs an interactive rebase in the background, so you may get a merge conflict if a later commit also changes these lines. |
 | `` <esc> `` | Выйти из сборщика пользовательских патчей |  |
 | `` / `` | Найти |  |
 

docs-master/keybindings/Keybindings_zh-CN.md

@@ -260,6 +260,7 @@ _图例：`<c-b>` 意味着ctrl+b, `<a-b>意味着Alt+b, `B` 意味着shift+b_
 | `` o `` | 打开文件 | 使用默认程序打开该文件 |
 | `` e `` | 编辑文件 | 使用外部编辑器打开文件 |
 | `` <space> `` | 添加/移除 行到补丁 |  |
+| `` d `` | Remove lines from commit | Remove the selected lines from this commit. This runs an interactive rebase in the background, so you may get a merge conflict if a later commit also changes these lines. |
 | `` <esc> `` | 退出逐行模式 |  |
 | `` / `` | 开始搜索 |  |
 

docs-master/keybindings/Keybindings_zh-TW.md

@@ -72,6 +72,7 @@ _說明：`<c-b>` 表示 Ctrl＋B、`<a-b>` 表示 Alt＋B，`B`表示 Shift＋B
 | `` o `` | 開啟檔案 | 使用預設軟體開啟 |
 | `` e `` | 編輯檔案 | 使用外部編輯器開啟 |
 | `` <space> `` | 向 (或從) 補丁中添加/刪除行 |  |
+| `` d `` | Remove lines from commit | Remove the selected lines from this commit. This runs an interactive rebase in the background, so you may get a merge conflict if a later commit also changes these lines. |
 | `` <esc> `` | 退出自訂補丁建立器 |  |
 | `` / `` | 搜尋 |  |
 

pkg/gui/controllers/patch_building_controller.go

@@ -1,7 +1,10 @@
 package controllers
 
 import (
+	"fmt"
+
 	"github.com/jesseduffield/gocui"
+	"github.com/jesseduffield/lazygit/pkg/gui/keybindings"
 	"github.com/jesseduffield/lazygit/pkg/gui/types"
 	"github.com/samber/lo"
 )
@@ -42,6 +45,14 @@ func (self *PatchBuildingController) GetKeybindings(opts types.KeybindingsOpts)
 			Description:     self.c.Tr.ToggleSelectionForPatch,
 			DisplayOnScreen: true,
 		},
+		{
+			Key:               opts.GetKey(opts.Config.Universal.Remove),
+			Handler:           self.DiscardSelection,
+			GetDisabledReason: self.getDisabledReasonForDiscard,
+			Description:       self.c.Tr.RemoveSelectionFromPatch,
+			Tooltip:           self.c.Tr.RemoveSelectionFromPatchTooltip,
+			DisplayOnScreen:   true,
+		},
 		{
 			Key:             opts.GetKey(opts.Config.Universal.Return),
 			Handler:         self.Escape,
@@ -168,6 +179,83 @@ func (self *PatchBuildingController) toggleSelection() error {
 	return nil
 }
 
+func (self *PatchBuildingController) getDisabledReasonForDiscard() *types.DisabledReason {
+	if !self.c.Git().Patch.PatchBuilder.CanRebase {
+		return &types.DisabledReason{Text: self.c.Tr.CanOnlyRemoveLinesFromLocalCommits}
+	}
+	if !self.c.Git().Patch.PatchBuilder.IsEmpty() {
+		return &types.DisabledReason{Text: self.c.Tr.MustClearPatchBeforeRemovingLines}
+	}
+	return nil
+}
+
+func (self *PatchBuildingController) DiscardSelection() error {
+	if self.c.UserConfig().Git.DiffContextSize == 0 {
+		return fmt.Errorf(self.c.Tr.Actions.NotEnoughContextToStage,
+			keybindings.Label(self.c.UserConfig().Keybinding.Universal.IncreaseContextInDiffView))
+	}
+
+	if ok, err := self.c.Helpers().PatchBuilding.ValidateNormalWorkingTreeState(); !ok {
+		return err
+	}
+
+	self.c.Confirm(types.ConfirmOpts{
+		Title:  self.c.Tr.RemoveLinesFromCommitTitle,
+		Prompt: self.c.Tr.RemoveLinesFromCommitPrompt,
+		HandleConfirm: func() error {
+			return self.removeSelectionFromCommit()
+		},
+	})
+
+	return nil
+}
+
+func (self *PatchBuildingController) addSelectionToPatch() error {
+	self.context().GetMutex().Lock()
+	defer self.context().GetMutex().Unlock()
+
+	filename := self.c.Contexts().CommitFiles.GetSelectedPath()
+	if filename == "" {
+		return nil
+	}
+
+	state := self.context().GetState()
+	lineIndicesToToggle := state.LineIndicesOfAddedOrDeletedLinesInSelectedPatchRange()
+	if len(lineIndicesToToggle) == 0 {
+		return nil
+	}
+
+	return self.c.Git().Patch.PatchBuilder.AddFileLineRange(filename, lineIndicesToToggle)
+}
+
+func (self *PatchBuildingController) removeSelectionFromCommit() error {
+	if err := self.addSelectionToPatch(); err != nil {
+		return err
+	}
+
+	if self.c.Git().Patch.PatchBuilder.IsEmpty() {
+		return nil
+	}
+
+	self.c.Helpers().PatchBuilding.Escape()
+
+	return self.c.WithWaitingStatus(self.c.Tr.RebasingStatus, func(gocui.Task) error {
+		commitIndex := self.getPatchCommitIndex()
+		self.c.LogAction(self.c.Tr.Actions.RemovePatchFromCommit)
+		err := self.c.Git().Patch.DeletePatchesFromCommit(self.c.Model().Commits, commitIndex)
+		return self.c.Helpers().MergeAndRebase.CheckMergeOrRebase(err)
+	})
+}
+
+func (self *PatchBuildingController) getPatchCommitIndex() int {
+	for index, commit := range self.c.Model().Commits {
+		if commit.Hash() == self.c.Git().Patch.PatchBuilder.To {
+			return index
+		}
+	}
+	return -1
+}
+
 func (self *PatchBuildingController) Escape() error {
 	context := self.c.Contexts().CustomPatchBuilder
 	state := context.GetState()