[studio,nostalgia] Fix PaletteEditor color update command merging, add setObsolete

src/olympic/studio/modlib/include/studio/undocommand.hpp

@@ -17,13 +17,22 @@ class NoChangesException: public ox::Exception {
 };
 
 class UndoCommand {
+	private:
+		bool m_obsolete{};
 	public:
 		virtual ~UndoCommand() noexcept = default;
 		virtual ox::Error redo() noexcept = 0;
 		virtual ox::Error undo() noexcept = 0;
 		[[nodiscard]]
 		virtual int commandId() const noexcept = 0;
-		virtual bool mergeWith(UndoCommand const&cmd) noexcept;
+		virtual bool mergeWith(UndoCommand &cmd) noexcept;
+		constexpr void setObsolete(bool obsolete) noexcept {
+			m_obsolete = obsolete;
+		}
+		[[nodiscard]]
+		constexpr bool isObsolete() const noexcept {
+			return m_obsolete;
+		}
 };
 
 }

src/olympic/studio/modlib/src/undocommand.cpp

@@ -3,7 +3,7 @@
 
 namespace studio {
 
-bool UndoCommand::mergeWith(UndoCommand const&) noexcept {
+bool UndoCommand::mergeWith(UndoCommand&) noexcept {
 	return false;
 }
 

src/olympic/studio/modlib/src/undostack.cpp

@@ -17,6 +17,10 @@ ox::Error UndoStack::push(ox::UPtr<UndoCommand> &&cmd) noexcept {
 		m_stack.emplace_back(std::move(cmd));
 		++m_stackIdx;
 	}
+	if ((*m_stack.back().unwrap())->isObsolete()) {
+		m_stack.pop_back();
+		--m_stackIdx;
+	}
 	return {};
 }