menu_displaylist: Hide History/Images/Music/Videos entries when history is disabled

When 'Settings -> Playlists -> History' (history_list_enable) is OFF,
CMD_EVENT_HISTORY_INIT early-returns and leaves g_defaults.content_history,
image_history, music_history, and video_history all NULL. The Playlists
tab generator was still appending entries for these with paths obtained
via playlist_get_conf_path(NULL), which returns NULL and renders as a
blank title. The icons and localized sublabels remained, producing four
"empty" rows in Main Menu -> Playlists.

Gate the four append calls additionally on the corresponding
g_defaults.*_history pointer being non-NULL. This also covers the
secondary early-return path in CMD_EVENT_HISTORY_INIT when
content_history_size is 0.

Mirror the same guard for the History entry in the rgui/glui (no nav
bar) branch.

Favorites is unaffected: g_defaults.content_favorites is initialized
independently of history_list_enable.

Author: LibretroAdmin

menu/menu_displaylist.c

@@ -4229,7 +4229,7 @@ static unsigned menu_displaylist_parse_playlists(
                         MENU_SETTING_ACTION, 0, 0, NULL))
                   count++;
 
-            if (settings->bools.menu_content_show_history)
+            if (settings->bools.menu_content_show_history && g_defaults.content_history)
                if (menu_entries_append(info_list,
                         playlist_get_conf_path(g_defaults.content_history),
                         MENU_ENUM_LABEL_LOAD_CONTENT_HISTORY_STR,
@@ -4239,7 +4239,7 @@ static unsigned menu_displaylist_parse_playlists(
          }
          else
          {
-            if (settings->bools.menu_content_show_history)
+            if (settings->bools.menu_content_show_history && g_defaults.content_history)
                if (menu_entries_append(info_list,
                         playlist_get_conf_path(g_defaults.content_history),
                         MENU_ENUM_LABEL_LOAD_CONTENT_HISTORY_STR,
@@ -4258,7 +4258,7 @@ static unsigned menu_displaylist_parse_playlists(
       }
 
 #ifdef HAVE_IMAGEVIEWER
-      if (settings->bools.menu_content_show_images)
+      if (settings->bools.menu_content_show_images && g_defaults.image_history)
          if (menu_entries_append(info_list,
                   playlist_get_conf_path(g_defaults.image_history),
                   MENU_ENUM_LABEL_GOTO_IMAGES_STR,
@@ -4267,7 +4267,7 @@ static unsigned menu_displaylist_parse_playlists(
             count++;
 #endif
 
-      if (settings->bools.menu_content_show_music)
+      if (settings->bools.menu_content_show_music && g_defaults.music_history)
          if (menu_entries_append(info_list,
                   playlist_get_conf_path(g_defaults.music_history),
                   MENU_ENUM_LABEL_GOTO_MUSIC_STR,
@@ -4276,7 +4276,7 @@ static unsigned menu_displaylist_parse_playlists(
             count++;
 
 #if defined(HAVE_FFMPEG) || defined(HAVE_MPV)
-      if (settings->bools.menu_content_show_video)
+      if (settings->bools.menu_content_show_video && g_defaults.video_history)
          if (menu_entries_append(info_list,
                   playlist_get_conf_path(g_defaults.video_history),
                   MENU_ENUM_LABEL_GOTO_VIDEO_STR,
@@ -15368,7 +15368,7 @@ bool menu_displaylist_ctl(enum menu_displaylist_ctl_state type,
                                  MENU_SETTING_ACTION, 0, 0, NULL))
                            count++;
 
-                     if (settings->bools.menu_content_show_history)
+                     if (settings->bools.menu_content_show_history && g_defaults.content_history)
                         if (menu_entries_append(info->list,
                                  playlist_get_conf_path(g_defaults.content_history),
                                  MENU_ENUM_LABEL_LOAD_CONTENT_HISTORY_STR,
@@ -15378,7 +15378,7 @@ bool menu_displaylist_ctl(enum menu_displaylist_ctl_state type,
                   }
                   else
                   {
-                     if (settings->bools.menu_content_show_history)
+                     if (settings->bools.menu_content_show_history && g_defaults.content_history)
                         if (menu_entries_append(info->list,
                                  playlist_get_conf_path(g_defaults.content_history),
                                  MENU_ENUM_LABEL_LOAD_CONTENT_HISTORY_STR,