Merge branch 'yem-kconfig-rc-fixes' of git://gitorious.org/linux-kconfig/linux-kconfig into kbuild/rc-fixes

1 files changed, 14 insertions, 1 deletions

diff --git a/scripts/kconfig/menu.c b/scripts/kconfig/menu.c
index b5c7d90df9df..fd3f0180e08f 100644
--- a/scripts/kconfig/menu.c
+++ b/scripts/kconfig/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);
 			}
 		}