Index: fold-const.c
===================================================================
--- fold-const.c	(revision 166974)
+++ fold-const.c	(working copy)
@@ -13415,7 +13415,7 @@ fold_ternary_loc (location_t loc, enum t
 	     a COND, which will recurse.  In that case, the COND_EXPR
 	     is probably the best choice, so leave it alone.  */
 	  && type == TREE_TYPE (arg0))
-	return pedantic_non_lvalue_loc (loc, arg0);
+	return pedantic_non_lvalue_loc (loc, unshare_expr (arg0));
 
       /* Convert A ? 0 : 1 to !A.  This prefers the use of NOT_EXPR
 	 over COND_EXPR in cases such as floating point comparisons.  */