X-Git-Url: https://jxself.org/git/?a=blobdiff_plain;f=config%2Fmenu.c;h=7e233a6ca64ef7faf1bc9390ec89cb90ccef2d98;hb=4c9a4d5505c463aa2a35b6a199910fd92e387566;hp=b5c7d90df9df801dac0ca12d64b609e686e74b62;hpb=e5ef38a8fa9ef524c3ef061083ce35d1529e5ea0;p=carl9170fw.git

diff --git a/config/menu.c b/config/menu.c
index b5c7d90..7e233a6 100644
--- 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;