mconf/nconf: mark empty menus/menuconfigs different from non-empty ones

[carl9170fw.git] / config / menu.c

diff --git a/config/menu.c b/config/menu.c
index b5c7d90df9df801dac0ca12d64b609e686e74b62..7e233a6ca64ef7faf1bc9390ec89cb90ccef2d98 100644 (file)
--- a/config/menu.c
+++ b/config/menu.c
@@ -146,11 +146,24 @@ struct property *menu_add_prop(enum prop_type type, char *prompt, struct expr *e
                        struct menu *menu = current_entry;
 
                        while ((menu = menu->parent) != NULL) {
+                               struct expr *dup_expr;
+
                                if (!menu->visibility)
                                        continue;
+                               /*
+                                * Do not add a reference to the
+                                * menu's visibility expression but
+                                * use a copy of it.  Otherwise the
+                                * expression reduction functions
+                                * will modify expressions that have
+                                * multiple references which can
+                                * cause unwanted side effects.
+                                */
+                               dup_expr = expr_copy(menu->visibility);
+
                                prop->visible.expr
                                        = expr_alloc_and(prop->visible.expr,
-                                                        menu->visibility);
+                                                        dup_expr);
                        }
                }
 
@@ -430,6 +443,22 @@ bool menu_has_prompt(struct menu *menu)
        return true;
 }
 
+/*
+ * Determine if a menu is empty.
+ * A menu is considered empty if it contains no or only
+ * invisible entries.
+ */
+bool menu_is_empty(struct menu *menu)
+{
+       struct menu *child;
+
+       for (child = menu->list; child; child = child->next) {
+               if (menu_is_visible(child))
+                       return(false);
+       }
+       return(true);
+}
+
 bool menu_is_visible(struct menu *menu)
 {
        struct menu *child;