Support using the selected commit's message in a fixup

I've optimised for muscle memory backwards compatibility here:
  - Outside interactive rebase: press 'f' then instead of a confirmation
panel, a menu appears where you can choose to keep the selected commit's
message
  - Inside interactive rebase: press 'f' then press 'c' to see the menu
for keeping the message, where if you press 'c' again it will retain the
current message. so 'fcc' is the chord to press.

We're also now showing the -C flag (which is what enables the behaviour)
against the todo.

I've picked the 'c' keybinding because 'C' was taken and it corresponds
to the flag. Previously that showed a warning about a change in
keybinding for cherry picking but it's been ages since we've made that
change so I'm happy to retire it.

docs-master/Config.md

@@ -713,6 +713,7 @@ keybinding:
     renameCommitWithEditor: R
     viewResetOptions: g
     markCommitAsFixup: f
+    setFixupMessage: c
     createFixupCommit: F
     squashAboveCommits: S
     moveDownCommit: <c-j>

docs-master/keybindings/Keybindings_en.md

@@ -89,6 +89,7 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` b `` | View bisect options |  |
 | `` s `` | Squash | Squash the selected commit into the commit below it. The selected commit's message will be appended to the commit below it. |
 | `` f `` | Fixup | Meld the selected commit into the commit below it. Similar to squash, but the selected commit's message will be discarded. |
+| `` c `` | Set fixup message | Set the message option for the fixup commit. The -C option means to use this commit's message instead of the target commit's message. |
 | `` r `` | Reword | Reword the selected commit's message. |
 | `` R `` | Reword with editor |  |
 | `` d `` | Drop | Drop the selected commit. This will remove the commit from the branch via a rebase. If the commit makes changes that later commits depend on, you may need to resolve merge conflicts. |

docs-master/keybindings/Keybindings_ja.md

@@ -69,6 +69,7 @@ _凡例：`＜c-b＞` はctrl+b、`＜a-b＞` はalt+b、`B` はshift+bを意味
 | `` b `` | bisectオプションを表示 |  |
 | `` s `` | スカッシュ | 選択したコミットをその下のコミットにスカッシュします。スカッシュとは複数のコミットを1つにまとめる操作です。選択したコミットのメッセージが下のコミットに追加されます。 |
 | `` f `` | フィックスアップ | 選択したコミットをその下のコミットにマージします。フィックスアップはスカッシュと似ていますが、選択したコミットのメッセージは破棄され、下のコミットのメッセージのみが保持されます。 |
+| `` c `` | Set fixup message | Set the message option for the fixup commit. The -C option means to use this commit's message instead of the target commit's message. |
 | `` r `` | メッセージ変更 | 選択したコミットのメッセージを変更します。 |
 | `` R `` | エディタでメッセージ変更 |  |
 | `` d `` | 削除 | 選択したコミットを削除します。これはリベースを通じてブランチからコミットを削除します。コミットが後続のコミットが依存する変更を行っている場合、マージコンフリクトを解決する必要があるかもしれません。 |

docs-master/keybindings/Keybindings_ko.md

@@ -298,6 +298,7 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` b `` | Bisect 옵션 보기 |  |
 | `` s `` | 스쿼시 | Squash the selected commit into the commit below it. The selected commit's message will be appended to the commit below it. |
 | `` f `` | Fixup | Meld the selected commit into the commit below it. Similar to squash, but the selected commit's message will be discarded. |
+| `` c `` | Set fixup message | Set the message option for the fixup commit. The -C option means to use this commit's message instead of the target commit's message. |
 | `` r `` | 커밋메시지 변경 | Reword the selected commit's message. |
 | `` R `` | 에디터에서 커밋메시지 수정 |  |
 | `` d `` | 커밋 삭제 | Drop the selected commit. This will remove the commit from the branch via a rebase. If the commit makes changes that later commits depend on, you may need to resolve merge conflicts. |

docs-master/keybindings/Keybindings_nl.md

@@ -160,6 +160,7 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` b `` | View bisect options |  |
 | `` s `` | Squash | Squash the selected commit into the commit below it. The selected commit's message will be appended to the commit below it. |
 | `` f `` | Fixup | Meld the selected commit into the commit below it. Similar to squash, but the selected commit's message will be discarded. |
+| `` c `` | Set fixup message | Set the message option for the fixup commit. The -C option means to use this commit's message instead of the target commit's message. |
 | `` r `` | Hernoem commit | Reword the selected commit's message. |
 | `` R `` | Hernoem commit met editor |  |
 | `` d `` | Verwijder commit | Drop the selected commit. This will remove the commit from the branch via a rebase. If the commit makes changes that later commits depend on, you may need to resolve merge conflicts. |

docs-master/keybindings/Keybindings_pl.md

@@ -62,6 +62,7 @@ _Legenda: `<c-b>` oznacza ctrl+b, `<a-b>` oznacza alt+b, `B` oznacza shift+b_
 | `` b `` | Zobacz opcje bisect |  |
 | `` s `` | Scal | Scal wybrany commit z commitami poniżej. Wiadomość wybranego commita zostanie dołączona do commita poniżej. |
 | `` f `` | Poprawka | Włącz wybrany commit do commita poniżej. Podobnie do fixup, ale wiadomość wybranego commita zostanie odrzucona. |
+| `` c `` | Set fixup message | Set the message option for the fixup commit. The -C option means to use this commit's message instead of the target commit's message. |
 | `` r `` | Przeformułuj | Przeformułuj wiadomość wybranego commita. |
 | `` R `` | Przeformułuj za pomocą edytora |  |
 | `` d `` | Usuń | Usuń wybrany commit. To usunie commit z gałęzi za pomocą rebazowania. Jeśli commit wprowadza zmiany, od których zależą późniejsze commity, być może będziesz musiał rozwiązać konflikty scalania. |

docs-master/keybindings/Keybindings_pt.md

@@ -164,6 +164,7 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` b `` | View bisect options |  |
 | `` s `` | Squash | Squash o commit selecionado no commit abaixo dele. A mensagem do commit selecionado será anexada ao commit abaixo dele. |
 | `` f `` | Fixup | Faça o commit selecionado no commit abaixo dele. Semelhante para o squash, mas a mensagem do commit selecionado será descartada. |
+| `` c `` | Set fixup message | Set the message option for the fixup commit. The -C option means to use this commit's message instead of the target commit's message. |
 | `` r `` | Reword | Repetir a mensagem de submissão selecionada. |
 | `` R `` | Republicar com o editor |  |
 | `` d `` | Descartar | Solte o commit selecionado. Isso irá remover o commit do branch através de uma rebase. Se o commit faz com que as alterações em commits posteriores dependem, você pode precisar resolver conflitos de merge. |

docs-master/keybindings/Keybindings_ru.md

@@ -170,6 +170,7 @@ _Связки клавиш_
 | `` b `` | Просмотреть параметры бинарного поиска |  |
 | `` s `` | Объединить коммиты (Squash) | Squash the selected commit into the commit below it. The selected commit's message will be appended to the commit below it. |
 | `` f `` | Объединить несколько коммитов в один отбросив сообщение коммита (Fixup)  | Meld the selected commit into the commit below it. Similar to squash, but the selected commit's message will be discarded. |
+| `` c `` | Set fixup message | Set the message option for the fixup commit. The -C option means to use this commit's message instead of the target commit's message. |
 | `` r `` | Перефразировать коммит | Reword the selected commit's message. |
 | `` R `` | Переписать коммит с помощью редактора |  |
 | `` d `` | Удалить коммит | Drop the selected commit. This will remove the commit from the branch via a rebase. If the commit makes changes that later commits depend on, you may need to resolve merge conflicts. |

docs-master/keybindings/Keybindings_zh-CN.md

@@ -126,6 +126,7 @@ _图例：`<c-b>` 意味着ctrl+b, `<a-b>意味着Alt+b, `B` 意味着shift+b_
 | `` b `` | 查看二分查找选项 |  |
 | `` s `` | 压缩(Squash) | 将已选提交压缩到该提交之下。这些选定的提交的消息会附加到该提交的消息之下。 |
 | `` f `` | 修正 （fixup） | 将选定的提交合并到其下面的提交中。与压缩类似，但所选提交的消息将被丢弃。 |
+| `` c `` | Set fixup message | Set the message option for the fixup commit. The -C option means to use this commit's message instead of the target commit's message. |
 | `` r `` | 改写提交 | 重写所选提交的消息。 |
 | `` R `` | 使用编辑器重命名提交 |  |
 | `` d `` | 删除提交 | 删除选中的提交。这将通过变基从分支中删除该提交，如果该提交修改的内容依赖于后续的提交，则需要解决合并冲突。 |

docs-master/keybindings/Keybindings_zh-TW.md

@@ -184,6 +184,7 @@ _說明：`<c-b>` 表示 Ctrl＋B、`<a-b>` 表示 Alt＋B，`B`表示 Shift＋B
 | `` b `` | 查看二分選項 |  |
 | `` s `` | 壓縮 (Squash) | Squash the selected commit into the commit below it. The selected commit's message will be appended to the commit below it. |
 | `` f `` | 修復 (Fixup) | Meld the selected commit into the commit below it. Similar to squash, but the selected commit's message will be discarded. |
+| `` c `` | Set fixup message | Set the message option for the fixup commit. The -C option means to use this commit's message instead of the target commit's message. |
 | `` r `` | 改寫提交 | 改寫選中的提交訊息 |
 | `` R `` | 使用編輯器改寫提交 |  |
 | `` d `` | 刪除提交 | Drop the selected commit. This will remove the commit from the branch via a rebase. If the commit makes changes that later commits depend on, you may need to resolve merge conflicts. |