feat(scummtr): Try to detect and reject MANIAC-V2-EN

This particular version has an original script bug that corrupts the
game when you modify it (the game will always switch to Demo mode).

The V1 English variant, and the V2 non-English variants don't have
this bug.

#12

NEWS.md

@@ -29,6 +29,7 @@
 
 ### Known bugs:
 
+- MANIAC-V2-EN is unsupported. This is because of an existing bug in the original game: any change made to the resources would amplify it and corrupt the game. Possible workaround: work from MANIAC-V1-EN or from a non-English version of Maniac Mansion V2.
 - ScummTR: the `-b` option may not correctly work with all games. Possible workaround: use the `-r` option.
 
 ### Portability (for developers):

src/ScummTr/script.cpp

@@ -1479,6 +1479,23 @@ void Script::_opv12()
 		_eatWordOrVar(opcode & 0x80);
 		break;
 	case 0x62: // stopScript
+		if (ScummRp::game.version == 2 && ScummRp::game.id == GID_MANIAC && _file->name() == "07.LFL" && _file->fullOffset() == 0x2351)
+		{
+			byte b;
+			b = _eatByteOrVar(opcode & 0x80);
+			if (b == 0x00 && _peekByte() != 0xD8)
+			{
+#ifndef SCUMMTR_OK_TO_CORRUPT_MANIAC_V2_EN
+				// https://github.com/dwatteau/scummtr/issues/12
+				throw Script::Error("This version of Maniac Mansion V2 has an original bug that corrupts it if you modify it");
+#endif
+			}
+		}
+		else
+		{
+			_eatByteOrVar(opcode & 0x80);
+		}
+		break;
 	case 0xE2: // stopScript
 		_eatByteOrVar(opcode & 0x80);
 		break;