Use SDL_bool instead an int return code in the SDL API

Most SDL functions used to indicate success or failure using an int return code. These functions have been changed to return SDL_bool.

Here is a coccinelle patch to change code that previously compared the return value to 0 and changes it to a boolean test:
@ bool_return_type @
identifier func =~ "^(Mix_FadeInMusic|Mix_FadeInMusicPos|Mix_GroupChannels|Mix_ModMusicJumpToOrder|Mix_OpenAudio|Mix_PlayMusic|Mix_SetMusicCMD|Mix_SetMusicPosition|Mix_SetSoundFonts|Mix_StartTrack)$";
@@
(
  func(
  ...
  )
- == 0
|
- func(
+ !func(
  ...
  )
- < 0
|
- func(
+ !func(
  ...
  )
- != 0
|
- func(
+ !func(
  ...
  )
- == -1
)

cmake/test/main.c

@@ -9,7 +9,7 @@ int main(int argc, char *argv[])
         return 1;
     }
     if (Mix_Init(0) == 0) {
-        SDL_Log("Mix_Init: no sound/music loaders supported (%s)\n", Mix_GetError());
+        SDL_Log("Mix_Init: no sound/music loaders supported (%s)\n", SDL_GetError());
     }
     Mix_Quit();
     SDL_Quit();

examples/playmus.c

@@ -189,7 +189,7 @@ int main(int argc, char *argv[])
 #endif
 
     /* Open the audio device */
-    if (Mix_OpenAudio(0, &spec) < 0) {
+    if (!Mix_OpenAudio(0, &spec)) {
         SDL_Log("Couldn't open audio: %s\n", SDL_GetError());
         return 2;
     } else {

examples/playwave.c

@@ -169,7 +169,7 @@ static void do_panning_update(void)
         if (!panningok) {
             SDL_Log("Mix_SetPanning(0, %d, %d) failed!\n",
                     (int) leftvol, (int) rightvol);
-            SDL_Log("Reason: [%s].\n", Mix_GetError());
+            SDL_Log("Reason: [%s].\n", SDL_GetError());
         }
 
         if ((leftvol == 255) || (leftvol == 0)) {
@@ -206,7 +206,7 @@ static void do_distance_update(void)
         distanceok = Mix_SetDistance(0, distance);
         if (!distanceok) {
             SDL_Log("Mix_SetDistance(0, %d) failed!\n", (int) distance);
-            SDL_Log("Reason: [%s].\n", Mix_GetError());
+            SDL_Log("Reason: [%s].\n", SDL_GetError());
         }
 
         if (distance == 0) {
@@ -240,7 +240,7 @@ static void do_position_update(void)
         if (!positionok) {
             SDL_Log("Mix_SetPosition(0, %d, %d) failed!\n",
                     (int) angle, (int) distance);
-            SDL_Log("Reason: [%s].\n", Mix_GetError());
+            SDL_Log("Reason: [%s].\n", SDL_GetError());
         }
 
         if (angle == 0) {
@@ -424,7 +424,7 @@ int main(int argc, char *argv[])
 #endif
 
     /* Open the audio device */
-    if (Mix_OpenAudio(0, &spec) < 0) {
+    if (!Mix_OpenAudio(0, &spec)) {
         SDL_Log("Couldn't open audio: %s\n", SDL_GetError());
         CleanUp(2);
     } else {
@@ -469,7 +469,7 @@ int main(int argc, char *argv[])
          (reverse_stereo))
     {
         SDL_Log("Failed to set up reverse stereo effect!\n");
-        SDL_Log("Reason: [%s].\n", Mix_GetError());
+        SDL_Log("Reason: [%s].\n", SDL_GetError());
     }
 
     /* Play and then exit */