Added a debug cheat to quickload but keep the currently loaded level.…

… (Shift+F9)

doc/ChangeLog.txt

@@ -613,3 +613,5 @@ FIXED: Make it possible to go through a certain closed gate on level 11 of Demo
 	Testcase: replays-testcases/Demo by Suave Prince level 11.p1r
 FIXED: When the prince jumps up at the bottom of a big pillar split between two rooms, a part near the top of the screen disappears.
 	Example: The top row in the first room of the original level 5.
+DONE: Added a debug cheat to quickload but keep the currently loaded level. (Shift+F9)
+	Motivation: https://forum.princed.org/viewtopic.php?p=32556#p32556

doc/Readme.txt

@@ -218,6 +218,12 @@ See SDLPoP.ini for details.
 * [: shift kid 1 pixel to the left
 * ]: shift kid 1 pixel to the right
 * T: Toggle timer (remaining minutes:seconds:ticks). Also shows the total elapsed ticks during playback.
+* Shift+F9: Quickload but keep the currently loaded level.
+	* Intended use: Suppose you made a quicksave after you got the prince or a guard into a specific position needed for a trick.
+	Then you try to do the trick, but you realize that you need to change the level slightly to make the trick work. So you edit the level.
+	But you can't use a (regular) quickload to get back to the saved position, because that would load the previous version of the level from the quicksave file.
+	In this situation, press Ctrl+A to load the new version of the level, then press Shift+F9 to load the quicksave onto this new level.
+	* Motivation: https://forum.princed.org/viewtopic.php?p=32556#p32556
 
 Where is the music?
 ----------------------

src/seg000.c

@@ -254,7 +254,15 @@ int quick_process(process_func_type process_func) {
 	int ok = 1;
 #define process(x) ok = ok && process_func(&(x), sizeof(x))
 	// level
-	process(level);
+#ifdef USE_DEBUG_CHEATS
+	// Don't load the level if the user holds either Shift key while pressing F9.
+	if (debug_cheats_enabled && (key_states[SDL_SCANCODE_LSHIFT] || key_states[SDL_SCANCODE_RSHIFT])) {
+		fseek(quick_fp, sizeof(level), SEEK_CUR);
+	} else
+#endif
+	{
+		process(level);
+	}
 	process(checkpoint);
 	process(upside_down);
 	process(drawn_room);