Loadso's Unload returns bool to indicate success/failure

include/SDL3/SDL_loadso.h

@@ -127,14 +127,16 @@ extern SDL_DECLSPEC SDL_FunctionPointer SDLCALL SDL_LoadFunction(SDL_SharedObjec
  * SDL_LoadFunction() will no longer be valid.
  *
  * \param handle a valid shared object handle returned by SDL_LoadObject().
+ * \returns a boolean value, where true indicates success and false
+ *          indicates failure; call SDL_GetError() for more information.
  *
  * \threadsafety It is safe to call this function from any thread.
  *
  * \since This function is available since SDL 3.2.0.
  *
  * \sa SDL_LoadObject
  */
-extern SDL_DECLSPEC void SDLCALL SDL_UnloadObject(SDL_SharedObject *handle);
+extern SDL_DECLSPEC bool SDLCALL SDL_UnloadObject(SDL_SharedObject *handle);
 
 /* Ends C function definitions when using C++ */
 #ifdef __cplusplus

src/loadso/dlopen/SDL_sysloadso.c

@@ -72,11 +72,17 @@ SDL_FunctionPointer SDL_LoadFunction(SDL_SharedObject *handle, const char *name)
     return symbol;
 }
 
-void SDL_UnloadObject(SDL_SharedObject *handle)
+bool SDL_UnloadObject(SDL_SharedObject *handle)
 {
-    if (handle) {
-        dlclose(handle);
+    if (!handle) {
+        return true;
+    }
+    int error_code = dlclose(handle);
+    if (error_code) {
+        SDL_SetError("Failed unloading library. Error code: %d. Message: %s
+                     error_code, (const char *)dlerror());
     }
+    return error_code == 0;
 }
 
 #endif // SDL_LOADSO_DLOPEN

src/loadso/dummy/SDL_sysloadso.c

@@ -37,9 +37,9 @@ SDL_FunctionPointer SDL_LoadFunction(SDL_SharedObject *handle, const char *name)
     return NULL;
 }
 
-void SDL_UnloadObject(SDL_SharedObject *handle)
+bool SDL_UnloadObject(SDL_SharedObject *handle)
 {
-    // no-op.
+    return true;
 }
 
 #endif // SDL_LOADSO_DUMMY

src/loadso/windows/SDL_sysloadso.c

@@ -58,11 +58,18 @@ SDL_FunctionPointer SDL_LoadFunction(SDL_SharedObject *handle, const char *name)
     return symbol;
 }
 
-void SDL_UnloadObject(SDL_SharedObject *handle)
+bool SDL_UnloadObject(SDL_SharedObject *handle)
 {
-    if (handle) {
-        FreeLibrary((HMODULE)handle);
+    if (!handle) {
+        return true;
+    }
+    bool success = FreeLibrary((HMODULE)handle);
+    if (!success) {
+        char errbuf[512];
+        SDL_snprintf(errbuf, sizeof (errbuf), "Failed unloading library");
+        WIN_SetError(errbuf);
     }
+    return success;
 }
 
 #endif // SDL_LOADSO_WINDOWS

test/testloadso.c

@@ -104,7 +104,11 @@ int main(int argc, char *argv[])
                 SDL_Log("Unloading library...");
             }
         }
-        SDL_UnloadObject(lib);
+        bool close_success = SDL_UnloadObject(lib);
+        if (!close_success) {
+            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL_UnloadObject('%s') failed: %s",
+                         libname, SDL_GetError());
+        }
     }
     SDL_Quit();
     SDLTest_CommonDestroyState(state);