DIRECTOR: Fix calling convention for b_go

1 files changed, 43 insertions, 19 deletions

diff --git a/engines/director/lingo/lingo-builtins.cpp b/engines/director/lingo/lingo-builtins.cpp
index f0e384d92c..8a465c585e 100644
--- a/engines/director/lingo/lingo-builtins.cpp
+++ b/engines/director/lingo/lingo-builtins.cpp
@@ -893,36 +893,60 @@ void Lingo::b_do(int nargs) {
 }
 
 void Lingo::b_go(int nargs) {
+	// Builtin function for go as used by the Director bytecode engine.
+	//
+	// Accepted arguments:
+	// "loop"
+	// "next"
+	// "previous"
+	// (STRING|INT) frame
+	// STRING movie, (STRING|INT) frame
+
 	if (nargs >= 1 && nargs <= 2) {
-		Datum frame = g_lingo->pop();
+		Datum firstArg = g_lingo->pop();
 		nargs -= 1;
-		if (frame.type == STRING) {
-			if (*frame.u.s == "loop") {
+		bool callSpecial = false;
+
+		if (firstArg.type == STRING) {
+			if (*firstArg.u.s == "loop") {
 				g_lingo->func_gotoloop();
-			} else if (*frame.u.s == "next") {
+				callSpecial = true;
+			} else if (*firstArg.u.s == "next") {
 				g_lingo->func_gotonext();
-			} else if (*frame.u.s == "previous") {
+				callSpecial = true;
+			} else if (*firstArg.u.s == "previous") {
 				g_lingo->func_gotoprevious();
-			} else {
-				Datum movie;
-				if (nargs > 0) {
-					movie = g_lingo->pop();
-					nargs -= 1;
-					if (movie.type != STRING) {
-						warning("b_go: movie arg should be of type STRING, not %s", movie.type2str());
-					}
-				}
-				g_lingo->func_goto(frame, movie);
+				callSpecial = true;
 			}
+		}
+
+		if (!callSpecial) {
+			Datum movie;
+			Datum frame;
+
 			if (nargs > 0) {
-				warning("b_go: ignoring %d extra args", nargs);
-				g_lingo->dropStack(nargs);
+				movie = firstArg;
+				if (movie.type != STRING) {
+					warning("b_go: movie arg should be of type STRING, not %s", movie.type2str());
+				}
+				frame = g_lingo->pop();
+				nargs -= 1;
+			} else {
+				frame = firstArg;
 			}
 
-		} else {
-			warning("b_go: frame arg should be of type STRING, not %s", frame.type2str());
+			if (frame.type != STRING && frame.type != INT) {
+				warning("b_go: frame arg should be of type STRING or INT, not %s", frame.type2str());
+			}
+
+			g_lingo->func_goto(frame, movie);
+		}
+
+		if (nargs > 0) {
+			warning("b_go: ignoring %d extra args", nargs);
 			g_lingo->dropStack(nargs);
 		}
+
 	} else {
 		warning("b_go: expected 1 or 2 args, not %d", nargs);
 		g_lingo->dropStack(nargs);