Fix: don't propagate shift/ctrl state till next game-tick (#9381)

When the game-loop is very slow, it was easily possible to start
the loop with _shift_pressed being false, but end with
_shift_pressed being true. This doesn't hurt the game as such,
but for the user this can be very weird: I pressed "Buy Vehicle",
pressed shift a bit later, and I still get a cost indication.

src/video/video_driver.cpp

@@ -116,21 +116,6 @@ void VideoDriver::Tick()
 		/* Avoid next_draw_tick getting behind more and more if it cannot keep up. */
 		if (this->next_draw_tick < now - ALLOWED_DRIFT * this->GetDrawInterval()) this->next_draw_tick = now;
 
-		/* Keep the interactive randomizer a bit more random by requesting
-		 * new values when-ever we can. */
-		InteractiveRandom();
-
-		this->InputLoop();
-
-		/* Check if the fast-forward button is still pressed. */
-		if (fast_forward_key_pressed && !_networking && _game_mode != GM_MENU) {
-			ChangeGameSpeed(true);
-			this->fast_forward_via_key = true;
-		} else if (this->fast_forward_via_key) {
-			ChangeGameSpeed(false);
-			this->fast_forward_via_key = false;
-		}
-
 		/* Locking video buffer can block (especially with vsync enabled), do it before taking game state lock. */
 		this->LockVideoBuffer();
 
@@ -139,9 +124,24 @@ void VideoDriver::Tick()
 			std::lock_guard<std::mutex> lock_wait(this->game_thread_wait_mutex);
 			std::lock_guard<std::mutex> lock_state(this->game_state_mutex);
 
+			/* Keep the interactive randomizer a bit more random by requesting
+			 * new values when-ever we can. */
+			InteractiveRandom();
+
 			this->DrainCommandQueue();
 
 			while (this->PollEvent()) {}
+			this->InputLoop();
+
+			/* Check if the fast-forward button is still pressed. */
+			if (fast_forward_key_pressed && !_networking && _game_mode != GM_MENU) {
+				ChangeGameSpeed(true);
+				this->fast_forward_via_key = true;
+			} else if (this->fast_forward_via_key) {
+				ChangeGameSpeed(false);
+				this->fast_forward_via_key = false;
+			}
+
 			::InputLoop();
 
 			/* Prevent drawing when switching mode, as windows can be removed when they should still appear. */