Handle pasting multi-line commit messages

When pasting a multi-line commit message into the subject field of the commit
editor, we would interpret the first newline as the confirmation for closing the
editor, and then all remaining characters as whatever command they are bound to,
resulting in executing all sorts of arbitrary commands.

Now we recognize this being a paste, and interpret the first newline as moving
to the description.

Also, prevent tabs in the pasted content from switching to the respective other
panel; simply insert four spaces instead, which should be good enough for the
leading indentation in pasted code snippets, for example.

Author: stefanhaller

Diff for: pkg/gui/controllers/commit_description_controller.go

@@ -28,7 +28,7 @@ func (self *CommitDescriptionController) GetKeybindings(opts types.KeybindingsOp
 	bindings := []*types.Binding{
 		{
 			Key:     opts.GetKey(opts.Config.Universal.TogglePanel),
-			Handler: self.switchToCommitMessage,
+			Handler: self.handleTogglePanel,
 		},
 		{
 			Key:     opts.GetKey(opts.Config.Universal.Return),
@@ -75,6 +75,32 @@ func (self *CommitDescriptionController) switchToCommitMessage() error {
 	return nil
 }
 
+func (self *CommitDescriptionController) handleTogglePanel() error {
+	// The default keybinding for this action is "<tab>", which means that we
+	// also get here when pasting multi-line text that contains tabs. In that
+	// case we don't want to toggle the panel, but insert the tab as a character
+	// (somehow, see below).
+	//
+	// Only do this if the TogglePanel command is actually mapped to "<tab>"
+	// (the default). If it's not, we can only hope that it's mapped to some
+	// ctrl key or fn key, which is unlikely to occur in pasted text. And if
+	// they mapped some *other* command to "<tab>", then we're totally out of
+	// luck.
+	if self.c.GocuiGui().IsPasting && self.c.UserConfig().Keybinding.Universal.TogglePanel == "<tab>" {
+		// Handling tabs in pasted commit messages is not optimal, but hopefully
+		// good enough for now. We simply insert 4 spaces without worrying about
+		// column alignment. This works well enough for leading indentation,
+		// which is common in pasted code snippets.
+		view := self.Context().GetView()
+		for range 4 {
+			view.Editor.Edit(view, gocui.KeySpace, ' ', 0)
+		}
+		return nil
+	}
+
+	return self.switchToCommitMessage()
+}
+
 func (self *CommitDescriptionController) close() error {
 	self.c.Helpers().Commits.CloseCommitMessagePanel()
 	return nil

Diff for: pkg/gui/controllers/commit_message_controller.go

@@ -48,7 +48,7 @@ func (self *CommitMessageController) GetKeybindings(opts types.KeybindingsOpts)
 		},
 		{
 			Key:     opts.GetKey(opts.Config.Universal.TogglePanel),
-			Handler: self.switchToCommitDescription,
+			Handler: self.handleTogglePanel,
 		},
 		{
 			Key:     opts.GetKey(opts.Config.CommitMessage.CommitMenu),
@@ -105,6 +105,32 @@ func (self *CommitMessageController) switchToCommitDescription() error {
 	return nil
 }
 
+func (self *CommitMessageController) handleTogglePanel() error {
+	// The default keybinding for this action is "<tab>", which means that we
+	// also get here when pasting multi-line text that contains tabs. In that
+	// case we don't want to toggle the panel, but insert the tab as a character
+	// (somehow, see below).
+	//
+	// Only do this if the TogglePanel command is actually mapped to "<tab>"
+	// (the default). If it's not, we can only hope that it's mapped to some
+	// ctrl key or fn key, which is unlikely to occur in pasted text. And if
+	// they mapped some *other* command to "<tab>", then we're totally out of
+	// luck.
+	if self.c.GocuiGui().IsPasting && self.c.UserConfig().Keybinding.Universal.TogglePanel == "<tab>" {
+		// It is unlikely that a pasted commit message contains a tab in the
+		// subject line, so it shouldn't matter too much how we handle it.
+		// Simply insert 4 spaces instead; all that matters is that we don't
+		// switch to the description panel.
+		view := self.context().GetView()
+		for range 4 {
+			view.Editor.Edit(view, gocui.KeySpace, ' ', 0)
+		}
+		return nil
+	}
+
+	return self.switchToCommitDescription()
+}
+
 func (self *CommitMessageController) handleCommitIndexChange(value int) error {
 	currentIndex := self.context().GetSelectedIndex()
 	newIndex := currentIndex + value
@@ -140,6 +166,20 @@ func (self *CommitMessageController) setCommitMessageAtIndex(index int) (bool, e
 }
 
 func (self *CommitMessageController) confirm() error {
+	// The default keybinding for this action is "<enter>", which means that we
+	// also get here when pasting multi-line text that contains newlines. In
+	// that case we don't want to confirm the commit, but switch to the
+	// description panel instead so that the rest of the pasted text goes there.
+	//
+	// Only do this if the SubmitEditorText command is actually mapped to
+	// "<enter>" (the default). If it's not, we can only hope that it's mapped
+	// to some ctrl key or fn key, which is unlikely to occur in pasted text.
+	// And if they mapped some *other* command to "<enter>", then we're totally
+	// out of luck.
+	if self.c.GocuiGui().IsPasting && self.c.UserConfig().Keybinding.Universal.SubmitEditorText == "<enter>" {
+		return self.switchToCommitDescription()
+	}
+
 	return self.c.Helpers().Commits.HandleCommitConfirm()
 }