Honor the LIBRETRO_DATABASE_DIRECTORY environment variable. (#17431)

* Partially revert a change made in 69ceb95ddc.

The change caused the 'libretro_directory' config option to always
revert to the default value, which was not intended behavior.

Reported-by: Michael Cook

* platform: Honor the LIBRETRO_DATABASE_DIRECTORY environment variable.

This is a follow-up to commit 69ceb95ddc.

* frontend/drivers/platform_unix.c
(libretro_database_directory): New variable.
(frontend_unix_get_env): Set DEFAULT_DIR_DATABASE to the value of
the LIBRETRO_DATABASE_DIRECTORY environment variable, if available.
* frontend/drivers/platform_win32.c: Likewise.
* configuration.c (config_load_file)
<libretro_database_directory>: New variable. Use the values of
the LIBRETRO_DATABASE_DIRECTORY environment variables instead of their
corresponding configured values, when set.
* docs/retroarch.6: Document.
* retroarch.c (retroarch_print_help): List supported environment
variables, and cross-reference the man page.

configuration.c

@@ -3571,6 +3571,7 @@ static bool config_load_file(global_t *global,
    char* libretro_directory                        = NULL;
    char* libretro_assets_directory                 = NULL;
    char* libretro_autoconfig_directory             = NULL;
+   char* libretro_database_directory               = NULL;
    char* libretro_system_directory                 = NULL;
    char* libretro_video_filter_directory           = NULL;
    char* libretro_video_shader_directory           = NULL;
@@ -3855,6 +3856,12 @@ static bool config_load_file(global_t *global,
          strlcpy(path_settings[i].ptr, tmp_str, PATH_MAX_LENGTH);
    }
 
+#if !IOS
+   if (config_get_path(conf, "libretro_directory", tmp_str, sizeof(tmp_str)))
+      configuration_set_string(settings,
+            settings->paths.directory_libretro, tmp_str);
+#endif
+
 #ifdef RARCH_CONSOLE
    if (conf)
       video_driver_load_settings(global, conf);
@@ -3871,13 +3878,19 @@ static bool config_load_file(global_t *global,
    }
 
    libretro_autoconfig_directory = getenv("LIBRETRO_AUTOCONFIG_DIRECTORY");
-   if (libretro_autoconfig_directory)
+   if (libretro_autoconfig_directory) /* override configuration value */
        configuration_set_string(settings,
 				settings->paths.directory_autoconfig,
 				libretro_autoconfig_directory);
 
+   libretro_database_directory = getenv("LIBRETRO_DATABASE_DIRECTORY");
+   if (libretro_database_directory) /* override configuration value */
+       configuration_set_string(settings,
+				settings->paths.path_content_database,
+				libretro_database_directory);
+
    libretro_system_directory = getenv("LIBRETRO_SYSTEM_DIRECTORY");
-   if (libretro_system_directory)
+   if (libretro_system_directory) /* override configuration value */
        configuration_set_string(settings,
 				settings->paths.directory_system,
 				libretro_system_directory);

docs/retroarch.6

@@ -1,6 +1,6 @@
 .\" retroarch.6:
 
-.TH  "RETROARCH" "6" "January 16, 2025" "RETROARCH" "System Manager's Manual: retroarch"
+.TH  "RETROARCH" "6" "January 18, 2025" "RETROARCH" "System Manager's Manual: retroarch"
 
 .SH NAME
 
@@ -261,6 +261,12 @@ Specify the directory where RetroArch looks for controller
 auto-configuration files, overriding the value of the
 "joypad_autoconfig_dir" configuration file option.
 
+.TP
+\fBLIBRETRO_DATABASE_DIRECTORY\fR
+Specify the directory where RetroArch looks for database files,
+overriding the value of the "content_database_path" configuration file
+option.
+
 .TP
 \fBLIBRETRO_SYSTEM_DIRECTORY\fR
 Specify the directory where RetroArch looks for system files,

frontend/drivers/platform_unix.c

@@ -1325,6 +1325,7 @@ static void frontend_unix_get_env(int *argc,
    const char* libretro_directory = getenv("LIBRETRO_DIRECTORY");
    const char* libretro_assets_directory = getenv("LIBRETRO_ASSETS_DIRECTORY");
    const char* libretro_autoconfig_directory = getenv("LIBRETRO_AUTOCONFIG_DIRECTORY");
+   const char* libretro_database_directory = getenv("LIBRETRO_DATABASE_DIRECTORY");
    const char* libretro_system_directory = getenv("LIBRETRO_SYSTEM_DIRECTORY");
    const char* libretro_video_filter_directory = getenv("LIBRETRO_VIDEO_FILTER_DIRECTORY");
    const char* libretro_video_shader_directory = getenv("LIBRETRO_VIDEO_SHADER_DIRECTORY");
@@ -1889,6 +1890,11 @@ static void frontend_unix_get_env(int *argc,
          "records_config", sizeof(g_defaults.dirs[DEFAULT_DIR_RECORD_CONFIG]));
    fill_pathname_join(g_defaults.dirs[DEFAULT_DIR_RECORD_OUTPUT], base_path,
          "records", sizeof(g_defaults.dirs[DEFAULT_DIR_RECORD_OUTPUT]));
+   if (!string_is_empty(libretro_database_directory))
+       strlcpy(g_defaults.dirs[DEFAULT_DIR_DATABASE],
+	       libretro_database_directory,
+	       sizeof(g_defaults.dirs[DEFAULT_DIR_DATABASE]));
+   else
        fill_pathname_join(g_defaults.dirs[DEFAULT_DIR_DATABASE], base_path,
              "database/rdb", sizeof(g_defaults.dirs[DEFAULT_DIR_DATABASE]));
    if (!string_is_empty(libretro_video_shader_directory))

frontend/drivers/platform_win32.c

@@ -568,6 +568,7 @@ static void frontend_win32_env_get(int *argc, char *argv[],
    const char *libretro_directory = getenv("LIBRETRO_DIRECTORY");
    const char *libretro_assets_directory = getenv("LIBRETRO_ASSETS_DIRECTORY");
    const char* libretro_autoconfig_directory = getenv("LIBRETRO_AUTOCONFIG_DIRECTORY");
+   const char* libretro_database_directory = getenv("LIBRETRO_DATABASE_DIRECTORY");
    const char* libretro_system_directory = getenv("LIBRETRO_SYSTEM_DIRECTORY");
    const char* libretro_video_filter_directory = getenv("LIBRETRO_VIDEO_FILTER_DIRECTORY");
    const char* libretro_video_shader_directory = getenv("LIBRETRO_VIDEO_SHADER_DIRECTORY");
@@ -595,6 +596,11 @@ static void frontend_win32_env_get(int *argc, char *argv[],
            ":\\filters\\video", sizeof(g_defaults.dirs[DEFAULT_DIR_VIDEO_FILTER]));
    fill_pathname_expand_special(g_defaults.dirs[DEFAULT_DIR_CHEATS],
       ":\\cheats", sizeof(g_defaults.dirs[DEFAULT_DIR_CHEATS]));
+   if (!string_is_empty(libretro_database_directory))
+       strlcpy(g_defaults.dirs[DEFAULT_DIR_DATABASE],
+	       libretro_database_directory,
+	       sizeof(g_defaults.dirs[DEFAULT_DIR_DATABASE]));
+   else
        fill_pathname_expand_special(g_defaults.dirs[DEFAULT_DIR_DATABASE],
            ":\\database\\rdb", sizeof(g_defaults.dirs[DEFAULT_DIR_DATABASE]));
    fill_pathname_expand_special(g_defaults.dirs[DEFAULT_DIR_PLAYLIST],

retroarch.c

@@ -6519,7 +6519,27 @@ static void retroarch_print_help(const char *arg0)
          "Path for the save state files (*.state). (DEPRECATED, use --appendconfig and savestate_directory)\n"
          , sizeof(buf) - _len);
 
+   /* Flush buffer here to avoid the error "error: string length ‘752’
+    * is greater than the length ‘509’ ISO C90 compilers are required
+    * to support" */
    fputs(buf, stdout);
+
+#if defined(__linux__) || defined(__GNU__) || (defined(BSD) && !defined(__MACH__))
+   buf[0] = '\0';
+   _len   = 0;
+   _len += strlcpy(buf + _len,
+         "\nThe following environment variables are supported:\n\n"
+         "  LIBRETRO_ASSETS_DIRECTORY\n"
+         "  LIBRETRO_AUTOCONFIG_DIRECTORY\n"
+         "  LIBRETRO_DATABASE_DIRECTORY\n"
+         "  LIBRETRO_DIRECTORY\n"
+         "  LIBRETRO_SYSTEM_DIRECTORY\n"
+         "  LIBRETRO_VIDEO_FILTER_DIRECTORY\n"
+         "  LIBRETRO_VIDEO_SHADER_DIRECTORY\n\n"
+         "Refer to `man 6 retroarch' for a description of what they do.\n"
+         , sizeof(buf) - _len);
+   fputs(buf, stdout);
+#endif
 }
 
 #ifdef HAVE_DYNAMIC