- fixed portal restoration on revisiting level in hub

Added function to FLevelLocals to test if map is being reentered

https://forum.zdoom.org/viewtopic.php?t=60455
(cherry picked from commit 29d2e77840)

src/g_levellocals.h

@@ -166,6 +166,12 @@ struct FLevelLocals
 		return headgamenode;
 	}
 
+	// Returns true if level is loaded from saved game or is being revisited as a part of a hub
+	bool		IsReentering() const
+	{
+		return savegamerestore 
+			|| (info != nullptr && info->Snapshot.mBuffer != nullptr && info->isValid());
+	}
 };
 
 extern FLevelLocals level;

src/p_setup.cpp

@@ -4102,7 +4102,7 @@ void P_SetupLevel (const char *lumpname, int position)
 	times[16].Clock();
 	if (reloop) P_LoopSidedefs (false);
 	PO_Init ();				// Initialize the polyobjs
-	if (!savegamerestore)
+	if (!level.IsReentering())
 		P_FinalizePortals();	// finalize line portals after polyobjects have been initialized. This info is needed for properly flagging them.
 	times[16].Unclock();
 

src/s_sound.cpp

@@ -477,7 +477,7 @@ void S_Start ()
 
 	// Don't start the music if loading a savegame, because the music is stored there.
 	// Don't start the music if revisiting a level in a hub for the same reason.
-	if (!savegamerestore && (level.info == nullptr || level.info->Snapshot.mBuffer == nullptr || !level.info->isValid()))
+	if (!level.IsReentering())
 	{
 		if (level.cdtrack == 0 || !S_ChangeCDMusic (level.cdtrack, level.cdid))
 			S_ChangeMusic (level.Music, level.musicorder);