Repeating SG1 with the same number is no-op

src/cmds.c

@@ -159,7 +159,6 @@ void commandSG() {
 		if (num == 0) {
 			mus_midi_stop();
 		} else {
-			mus_midi_stop();
 			mus_midi_start(num, loopcnt);
 		}
 		DEBUG_COMMAND("SG1 %d:\n", num);

src/midi.emscripten.c

@@ -67,6 +67,9 @@ static int midi_exit() {
 }
 
 static int midi_start(int no, int loop, char *data, int datalen) {
+	if (midino == no)
+		return OK;
+
 	EM_ASM_ARGS({ xsystem35.midiPlayer.play($0, $1, $2); }, loop, data, datalen);
 
 	midino = no;

src/midi.sdlmixer.c

@@ -75,6 +75,9 @@ static int midi_exit() {
 }
 
 static int midi_start(int no, int loop, char *data, int datalen) {
+	if (midino == no)
+		return OK;
+
 	midi_stop();
 
 	SDL_RWops *rwops = SDL_RWFromConstMem(data, datalen);