Small fixes for DOS

Adjusting a few definitions to help the DOS version. It is still
not really operational, but these changes cause no harm elsewhere.

Author: zoltanvb

core_info.c

@@ -2118,7 +2118,7 @@ static core_info_list_t *core_info_list_new(const char *path,
       info->core_file_id.str  = strdup(core_file_id);
       info->core_file_id.hash = core_info_hash_string(core_file_id);
 
-      strlcpy(core_file_id + _len, ".info", sizeof(core_file_id) - _len);
+      strlcpy(core_file_id + _len, FILE_PATH_CORE_INFO_EXTENSION, sizeof(core_file_id) - _len);
 
       /* Parse core info file */
       if ((conf = core_info_get_config_file(core_file_id, info_dir)))

file_path_special.h

@@ -39,7 +39,11 @@ RETRO_BEGIN_DECLS
 #define FILE_PATH_AUTO_EXTENSION ".auto"
 #define FILE_PATH_BSV_EXTENSION ".replay"
 #define FILE_PATH_OPT_EXTENSION ".opt"
+#ifdef DJGPP
+#define FILE_PATH_CORE_INFO_EXTENSION ".inf"
+#else
 #define FILE_PATH_CORE_INFO_EXTENSION ".info"
+#endif
 #define FILE_PATH_CONFIG_EXTENSION ".cfg"
 #define FILE_PATH_REMAP_EXTENSION ".rmp"
 #define FILE_PATH_RTC_EXTENSION ".rtc"
@@ -91,8 +95,13 @@ RETRO_BEGIN_DECLS
 #define FILE_PATH_CONTENT_MUSIC_HISTORY "content_music_history.lpl"
 #define FILE_PATH_CONTENT_VIDEO_HISTORY "content_video_history.lpl"
 #define FILE_PATH_CORE_OPTIONS_CONFIG "retroarch-core-options.cfg"
+#ifdef DJGPP
+#define FILE_PATH_MAIN_CONFIG "retrodos.cfg"
+#define FILE_PATH_SALAMANDER_CONFIG "retrosal.cfg"
+#else
 #define FILE_PATH_MAIN_CONFIG "retroarch.cfg"
 #define FILE_PATH_SALAMANDER_CONFIG "retroarch-salamander.cfg"
+#endif
 #define FILE_PATH_BACKGROUND_IMAGE "bg.png"
 #define FILE_PATH_TTF_FONT "font.ttf"
 #define FILE_PATH_RUNTIME_EXTENSION ".lrtl"

frontend/drivers/platform_dos.c

@@ -58,7 +58,7 @@ static void frontend_dos_get_env_settings(int *argc, char *argv[],
    if ((slash = strrchr(base_path, '/')))
       *slash = '\0';
    slash = strrchr(base_path, '/');
-   if (slash && strcasecmp(slash, "/cores"))
+   if (slash && strcasecmp(slash, "/cores") == 0)
       *slash = '\0';
 
    fill_pathname_join(g_defaults.dirs[DEFAULT_DIR_CORE], base_path,