Clean up future save states from the old rewind timeline

src/core/imgui_overlays.cpp

@@ -1614,9 +1614,16 @@ void ImGuiManager::RenderRewindSelector()
     {
       // Queue the state load to run on the CPU thread
       const std::string state_path = states[current_index].state_path;
-      Host::RunOnCPUThread([state_path]() {
+      const u32 selected_frame = states[current_index].frame_number;
+
+      Host::RunOnCPUThread([state_path, selected_frame]() {
         Error error;
-        if (!System::LoadState(state_path.c_str(), &error, true, false))
+        if (System::LoadState(state_path.c_str(), &error, true, false))
+        {
+          // Delete all states that occurred after this one (future states from old timeline)
+          System::DeleteRewindStatesAfter(selected_frame);
+        }
+        else
         {
           Host::AddIconOSDMessage("RewindLoadState", ICON_EMOJI_WARNING,
                                  fmt::format("Failed to load rewind state: {}", error.GetDescription()),

src/core/system.cpp

@@ -5215,6 +5215,27 @@ void System::SaveRewindState()
   }
 }
 
+void System::DeleteRewindStatesAfter(u32 frame_number)
+{
+  const std::string rewind_dir = GetRewindStateSaveDirectory();
+  if (rewind_dir.empty())
+    return;
+
+  std::vector<RewindStateInfo> existing_states = GetAvailableRewindStates();
+  for (const RewindStateInfo& state : existing_states)
+  {
+    // Delete all states with frame numbers greater than the selected one (more recent states)
+    if (state.frame_number > frame_number)
+    {
+      DEBUG_LOG("Deleting future rewind state: {} (frame {})", state.state_path, state.frame_number);
+      if (FileSystem::FileExists(state.state_path.c_str()))
+        FileSystem::DeleteFile(state.state_path.c_str());
+      if (FileSystem::FileExists(state.screenshot_path.c_str()))
+        FileSystem::DeleteFile(state.screenshot_path.c_str());
+    }
+  }
+}
+
 void System::OpenRewindStateSelector()
 {
   if (!IsValid() || !g_settings.rewind_enable || !g_settings.rewind_use_save_states)

src/core/system.h

@@ -374,6 +374,9 @@ std::vector<RewindStateInfo> GetAvailableRewindStates();
 /// Saves a rewind state to disk (only when using save state-based rewinding).
 void SaveRewindState();
 
+/// Deletes all rewind states with frame numbers greater than the specified frame.
+void DeleteRewindStatesAfter(u32 frame_number);
+
 /// Opens the rewind state selector UI.
 void OpenRewindStateSelector();