[retro-gtk] core: Throw an error when the game failed loading

[Adrien Plazas <aplazas src gnome org>]

commit 911c3ba9cc47fd7e0357a743f65312767a53124a
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Sat Jul 31 09:03:48 2021 +0200

    core: Throw an error when the game failed loading
    
    This properly supports loading games and this avoids retrieving the AV
    info if the game failed loading, matching what is stated by libretro.h
    in the documentation of retro_load_game() and
    retro_get_system_av_info().

 retro-runner/retro-core.c         | 35 +++++++++++++++++++++++++++--------
 shared/retro-core-error-private.h |  2 ++
 2 files changed, 29 insertions(+), 8 deletions(-)
---
diff --git a/retro-runner/retro-core.c b/retro-runner/retro-core.c
index 7cd2e15..415c2ab 100644
--- a/retro-runner/retro-core.c
+++ b/retro-runner/retro-core.c
@@ -863,9 +863,10 @@ load_discs (RetroCore  *self,
   }, catch, error);
 }
 
-static gboolean
-load_game (RetroCore     *self,
-           RetroGameInfo *game)
+static void
+load_game (RetroCore      *self,
+           RetroGameInfo  *game,
+           GError        **error)
 {
   RetroUnloadGame unload_game;
   RetroLoadGame load_game;
@@ -882,13 +883,28 @@ load_game (RetroCore     *self,
   game_loaded = load_game (game);
   set_game_loaded (self, game_loaded);
 
+  if (G_UNLIKELY (!game_loaded)) {
+    if (game == NULL)
+      g_set_error_literal (error,
+                           RETRO_CORE_ERROR,
+                           RETRO_CORE_ERROR_COULDNT_LOAD_NO_GAME,
+                           "Coulnd't load no game.");
+    else
+      g_set_error_literal (error,
+                           RETRO_CORE_ERROR,
+                           RETRO_CORE_ERROR_COULDNT_LOAD_GAME,
+                           "Coulnd't load the game.");
+
+    return;
+  }
+
+  /* We must get the system AV info *only* once loading the game *succeeded*,
+   * not just once it completed. */
   get_system_av_info = retro_module_get_get_system_av_info (self->module);
   get_system_av_info (&info);
   retro_core_set_system_av_info (self, &info);
   if (self->renderer)
     retro_renderer_realize (self->renderer, info.geometry.max_width, info.geometry.max_height);
-
-  return game_loaded;
 }
 
 static void
@@ -901,7 +917,9 @@ load_medias (RetroCore  *self,
   length = self->media_uris == NULL ? 0 : g_strv_length (self->media_uris);
 
   if (length == 0) {
-    load_game (self, NULL);
+    retro_try_propagate ({
+      load_game (self, NULL, &catch);
+    }, catch, error);
 
     return;
   }
@@ -912,8 +930,9 @@ load_medias (RetroCore  *self,
                                      &catch);
   }, catch, error);
 
-  if (!load_game (self, game_info))
-    return;
+  retro_try_propagate ({
+    load_game (self, game_info, &catch);
+  }, catch, error);
 
   if (self->disk_control_callback != NULL)
     retro_try_propagate ({
diff --git a/shared/retro-core-error-private.h b/shared/retro-core-error-private.h
index 7fc8674..f18c49c 100644
--- a/shared/retro-core-error-private.h
+++ b/shared/retro-core-error-private.h
@@ -13,6 +13,8 @@ G_BEGIN_DECLS
 #define RETRO_CORE_ERROR (retro_core_error_quark ())
 
 enum {
+  RETRO_CORE_ERROR_COULDNT_LOAD_GAME,
+  RETRO_CORE_ERROR_COULDNT_LOAD_NO_GAME,
   RETRO_CORE_ERROR_COULDNT_ACCESS_FILE,
   RETRO_CORE_ERROR_COULDNT_SERIALIZE,
   RETRO_CORE_ERROR_COULDNT_DESERIALIZE,