Change the selection before committing deletions of lines

For whatever reason this was sometimes being done after the commit,
which resulted in a lot of code only working by coincidence when the
grid commit handler happened to be the first one to be called.

aegisub/src/ass_karaoke.cpp

@@ -315,10 +315,10 @@ void AssKaraoke::SplitLines(std::set<AssDialogue*> const& lines, agi::Context *c
 
 	if (!did_split) return;
 
-	c->ass->Commit(_("splitting"), AssFile::COMMIT_DIAG_ADDREM | AssFile::COMMIT_DIAG_FULL);
-
 	AssDialogue *new_active = c->selectionController->GetActiveLine();
 	if (!sel.count(c->selectionController->GetActiveLine()))
 		new_active = *sel.begin();
 	c->selectionController->SetSelectionAndActive(sel, new_active);
+
+	c->ass->Commit(_("splitting"), AssFile::COMMIT_DIAG_ADDREM | AssFile::COMMIT_DIAG_FULL);
 }

aegisub/src/base_grid.cpp

@@ -320,14 +320,8 @@ void BaseGrid::UpdateMaps(bool preserve_selected_rows) {
 		SetSelectedSet(new_sel);
 	}
 
-	// Force a reannounce of the active line if it hasn't changed, as it isn't
-	// safe to touch the active line while processing a commit event which would
-	// cause this function to be called
-	AssDialogue *line = active_line;
-	active_line = nullptr;
-
 	// The active line may have ceased to exist; pick a new one if so
-	if (line_index_map.size() && line_index_map.find(line) == line_index_map.end()) {
+	if (line_index_map.size() && !line_index_map.count(active_line)) {
 		if (active_row < (int)index_line_map.size())
 			SetActiveLine(index_line_map[active_row]);
 		else if (preserve_selected_rows && !selection.empty())
@@ -335,9 +329,6 @@ void BaseGrid::UpdateMaps(bool preserve_selected_rows) {
 		else
 			SetActiveLine(index_line_map.back());
 	}
-	else {
-		SetActiveLine(line);
-	}
 
 	if (selection.empty() && active_line) {
 		Selection sel;

aegisub/src/command/edit.cpp

@@ -494,11 +494,11 @@ static void delete_lines(agi::Context *c, wxString const& commit_message) {
 		c->ass->InsertLine(new_active);
 	}
 
-	c->ass->Commit(commit_message, AssFile::COMMIT_DIAG_ADDREM);
-
 	sel.clear();
 	sel.insert(new_active);
 	c->selectionController->SetSelectionAndActive(sel, new_active);
+
+	c->ass->Commit(commit_message, AssFile::COMMIT_DIAG_ADDREM);
 }
 
 struct edit_line_copy : public validate_sel_nonempty {
@@ -670,6 +670,7 @@ static void combine_lines(agi::Context *c, void (*combiner)(AssDialogue *, AssDi
 	sel.clear();
 	sel.insert(first);
 	c->selectionController->SetSelectionAndActive(sel, first);
+
 	c->ass->Commit(message, AssFile::COMMIT_DIAG_ADDREM | AssFile::COMMIT_DIAG_FULL);
 }
 

aegisub/src/subs_controller.cpp

@@ -208,7 +208,8 @@ void SubsController::Close() {
 	redo_stack.clear();
 	autosaved_commit_id = saved_commit_id = commit_id + 1;
 	filename.clear();
-	context->ass->Line.clear();
+	AssFile blank;
+	swap(blank.Line, context->ass->Line);
 	context->ass->LoadDefault();
 	context->ass->Commit("", AssFile::COMMIT_NEW);
 }