SDL_mixer: fixed MID_MUSIC case in Mix_LoadMUSType_RW():

From 1f596b43a0a5133be901dd6ab930f83c9a14fdd1 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Sun, 4 Apr 2021 00:33:32 +0300
Subject: [PATCH] fixed MID_MUSIC case in Mix_LoadMUSType_RW():

without this, music->error might have never set to true.
---
 music.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/music.c b/music.c
index 680adf8..8fe8eca 100644
--- a/music.c
+++ b/music.c
@@ -672,12 +672,14 @@ Mix_Music *Mix_LoadMUSType_RW(SDL_RWops *rw, Mix_MusicType type, int freesrc)
 #ifdef MID_MUSIC
 	case MUS_MID:
 		music->type = MUS_MID;
+		music->error = 1;
 #ifdef USE_NATIVE_MIDI
 		if ( native_midi_ok ) {
 			music->data.nativemidi = native_midi_loadsong_RW(rw, freesrc);
 			if ( music->data.nativemidi == NULL ) {
 				Mix_SetError("%s", native_midi_error());
-				music->error = 1;
+			} else {
+				music->error = 0;
 			}
 			break;
 		}
@@ -685,8 +687,8 @@ Mix_Music *Mix_LoadMUSType_RW(SDL_RWops *rw, Mix_MusicType type, int freesrc)
 #ifdef USE_FLUIDSYNTH_MIDI
 		if ( fluidsynth_ok ) {
 			music->data.fluidsynthmidi = fluidsynth_loadsong_RW(rw, freesrc);
-			if ( music->data.fluidsynthmidi == NULL ) {
-				music->error = 1;
+			if ( music->data.fluidsynthmidi != NULL ) {
+				music->error = 0;
 			}
 			break;
 		}
@@ -696,11 +698,11 @@ Mix_Music *Mix_LoadMUSType_RW(SDL_RWops *rw, Mix_MusicType type, int freesrc)
 			music->data.midi = Timidity_LoadSong_RW(rw, freesrc);
 			if ( music->data.midi == NULL ) {
 				Mix_SetError("%s", Timidity_Error());
-				music->error = 1;
+			} else {
+				music->error = 0;
 			}
 		} else {
 			Mix_SetError("%s", Timidity_Error());
-			music->error = 1;
 		}
 #endif
 		break;