Restructure per-core configs.

Merging yesterday was probably a bit premature.

One issue I overlooked was that per-core configs were not flushed to disk
when loading a new core on PC. The per-core flushing only happened on
main_exit(), which is only run on application termination. This hence
would only work with consoles with exitspawn.

config_set_defaults() must be called when loading per-core-specifics as
well or lots of options silently leak into other core specific configs
when cores are changed.

The handling with g_extern.config_path and original_config_path was
difficult logic and very error prone considering it was mutated aribitrarily by RGUI.
I've removed the original config path concept and stuck
with that config_path is *only* for global config, and
core_specific_config_path is for core-specifics (which are resolved
during config load). Saves some memory too,
which is always nice.

The block_config_read solution I proposed yesterday was not good after
all (in fact, broken on PC), and the current solution should work better.

"RetroArch Config" option in RGUI now only shows global config.

frontend/frontend.c

@@ -285,12 +285,13 @@ void main_exit(args_type() args)
 
    if (g_extern.config_save_on_exit && *g_extern.config_path)
    {
+      // save last core-specific config to the default config location, needed on
+      // consoles for core switching and reusing last good config for new cores.
       config_save_file(g_extern.config_path);
 
-      // save last core-specific config to the default config location, needed on
-      // consoles for core switching and reusing last good config for new cores
-      if (*g_extern.original_config_path && strcmp(g_extern.config_path, g_extern.original_config_path) != 0)
-         config_save_file(g_extern.original_config_path);
+      // Flush out the core specific config.
+      if (*g_extern.core_specific_config_path)
+         config_save_file(g_extern.core_specific_config_path);
    }
 #endif
 
@@ -373,7 +374,7 @@ returntype main_entry(signature())
          menu_rom_history_push_current();
    }
 
-   while(!main_entry_iterate(signature_expand(), args));
+   while (!main_entry_iterate(signature_expand(), args));
 #else
    while ((g_extern.is_paused && !g_extern.is_oneshot) ? rarch_main_idle_iterate() : rarch_main_iterate());
 #endif

frontend/menu/menu_common.c

@@ -1515,7 +1515,6 @@ bool menu_replace_config(const char *path)
 
    // Load dummy core.
    *g_extern.fullpath = '\0';
-   *g_extern.original_config_path = '\0';
    *g_settings.libretro = '\0'; // Load core in new config.
    g_extern.lifecycle_state |= (1ULL << MODE_LOAD_GAME);
    rgui->load_no_rom = false;

frontend/menu/menu_settings.c

@@ -444,17 +444,11 @@ int menu_set_settings(void *data, unsigned setting, unsigned action)
             g_extern.config_save_on_exit = true;
          break;
       case RGUI_SETTINGS_PER_CORE_CONFIG:
-         g_extern.block_config_read = false;
          if (action == RGUI_ACTION_OK || action == RGUI_ACTION_RIGHT 
                || action == RGUI_ACTION_LEFT)
             g_settings.core_specific_config = !g_settings.core_specific_config;
          else if (action == RGUI_ACTION_START)
             g_settings.core_specific_config = default_core_specific_config;
-
-         if (g_settings.core_specific_config && *g_extern.core_specific_config_path)
-            strlcpy(g_extern.config_path, g_extern.core_specific_config_path, sizeof(g_extern.config_path));
-         else if (!g_settings.core_specific_config && *g_extern.original_config_path)
-            strlcpy(g_extern.config_path, g_extern.original_config_path, sizeof(g_extern.config_path));
          break;
 #if defined(HAVE_THREADS)
       case RGUI_SETTINGS_SRAM_AUTOSAVE:

general.h

@@ -363,6 +363,8 @@ struct global
 #ifdef HAVE_RMENU
    char menu_texture_path[PATH_MAX];
 #endif
+
+   // Config associated with global "default" config.
    char config_path[PATH_MAX];
    char append_config_path[PATH_MAX];
    char input_config_path[PATH_MAX];
@@ -652,7 +654,7 @@ struct global
    bool libretro_no_rom;
    bool libretro_dummy;
 
-   char original_config_path[PATH_MAX];
+   // Config file associated with per-core configs.
    char core_specific_config_path[PATH_MAX];
 };
 
@@ -684,7 +686,7 @@ const char *config_get_default_audio(void);
 const char *config_get_default_input(void);
 
 #include "conf/config_file.h"
-bool config_load_file(const char *path);
+bool config_load_file(const char *path, bool set_defaults);
 bool config_save_file(const char *path);
 bool config_read_keybinds(const char *path);
 

settings.c

@@ -438,51 +438,54 @@ void config_set_defaults(void)
 
 static void parse_config_file(void);
 
+static void config_load_core_specific(void)
+{
+   *g_extern.core_specific_config_path = '\0';
+
+   if (!*g_settings.libretro || g_extern.libretro_dummy)
+      return;
+
+   if (*g_settings.rgui_config_directory)
+   {
+      path_resolve_realpath(g_settings.rgui_config_directory, sizeof(g_settings.rgui_config_directory));
+      strlcpy(g_extern.core_specific_config_path, g_settings.rgui_config_directory, sizeof(g_extern.core_specific_config_path));
+   }
+   else
+   {
+      // Use original config file's directory as a fallback.
+      fill_pathname_basedir(g_extern.core_specific_config_path, g_extern.config_path, sizeof(g_extern.core_specific_config_path));
+   }
+
+   fill_pathname_dir(g_extern.core_specific_config_path, g_settings.libretro, ".cfg", sizeof(g_extern.core_specific_config_path));
+
+   if (g_settings.core_specific_config)
+   {
+      char tmp[PATH_MAX];
+      strlcpy(tmp, g_settings.libretro, sizeof(tmp));
+      RARCH_LOG("Loading core-specific config from: %s.\n", g_extern.core_specific_config_path);
+
+      if (!config_load_file(g_extern.core_specific_config_path, true))
+         RARCH_WARN("Core-specific config not found, reusing last config.\n");
+
+      // don't have the core config file overwrite the libretro path
+      strlcpy(g_settings.libretro, tmp, sizeof(g_settings.libretro));
+   }
+}
+
 void config_load(void)
 {
+   // Flush out per-core configs before loading a new config.
+   if (*g_extern.core_specific_config_path && g_extern.config_save_on_exit)
+      config_save_file(g_extern.core_specific_config_path);
+
    if (!g_extern.block_config_read)
    {
       config_set_defaults();
       parse_config_file();
    }
 
-   if (!*g_extern.original_config_path)
-   {
-      // save the original path for saving. a copy of the last core's settings is always saved to the original config file path for future launches
-      path_resolve_realpath(g_extern.config_path, sizeof(g_extern.config_path));
-      strlcpy(g_extern.original_config_path, g_extern.config_path, sizeof(g_extern.original_config_path));
-   }
-   
-   if (*g_settings.libretro)
-   {
-      if (*g_settings.rgui_config_directory)
-      {
-         path_resolve_realpath(g_settings.rgui_config_directory, sizeof(g_settings.rgui_config_directory));
-         strlcpy(g_extern.core_specific_config_path, g_settings.rgui_config_directory, sizeof(g_extern.core_specific_config_path));
-      }
-      else
-      {
-         // use original config file's directory
-         strlcpy(g_extern.core_specific_config_path, g_extern.original_config_path, sizeof(g_extern.core_specific_config_path));
-         path_basedir(g_extern.core_specific_config_path);
-      }
-
-      fill_pathname_dir(g_extern.core_specific_config_path, g_settings.libretro, ".cfg", sizeof(g_extern.core_specific_config_path));
-
-      if (g_settings.core_specific_config)
-      {
-         char tmp[PATH_MAX];
-         strlcpy(tmp, g_settings.libretro, sizeof(tmp));
-         strlcpy(g_extern.config_path, g_extern.core_specific_config_path, sizeof(g_extern.config_path));
-         RARCH_LOG("Loading core-specific config from: %s.\n", g_extern.config_path);
-
-         if (!config_load_file(g_extern.config_path))
-            RARCH_WARN("Core-specific config not found, reusing last config.\n");
-
-         // don't have the core config file overwrite the libretro path
-         strlcpy(g_settings.libretro, tmp, sizeof(g_settings.libretro));
-      }
-   }
+   // Per-core config handling.
+   config_load_core_specific();
 }
 
 static config_file_t *open_default_config_file(void)
@@ -614,12 +617,12 @@ static void parse_config_file(void)
    if (*g_extern.config_path)
    {
       RARCH_LOG("Loading config from: %s.\n", g_extern.config_path);
-      ret = config_load_file(g_extern.config_path);
+      ret = config_load_file(g_extern.config_path, false);
    }
    else
    {
       RARCH_LOG("Loading default config.\n");
-      ret = config_load_file(NULL);
+      ret = config_load_file(NULL, false);
       if (*g_extern.config_path)
          RARCH_LOG("Found default config: %s.\n", g_extern.config_path);
    }
@@ -633,7 +636,7 @@ static void parse_config_file(void)
    }
 }
 
-bool config_load_file(const char *path)
+bool config_load_file(const char *path, bool set_defaults)
 {
    unsigned i;
    config_file_t *conf = NULL;
@@ -650,6 +653,9 @@ bool config_load_file(const char *path)
    if (conf == NULL)
       return true;
 
+   if (set_defaults)
+      config_set_defaults();
+
    char *save;
    char tmp_append_path[PATH_MAX]; // Don't destroy append_config_path.
    strlcpy(tmp_append_path, g_extern.append_config_path, sizeof(tmp_append_path));