[Bug tree-optimization/86532] [9 Regression] Wrong code due to a wrong strlen folding starting with r262522

[bernd.edlinger at hotmail dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86532

--- Comment #3 from Bernd Edlinger <bernd.edlinger at hotmail dot de> ---
Hi Martin,
how about:

--- gcc/expr.c.jj       2018-07-09 22:33:48.000000000 +0200
+++ gcc/expr.c  2018-07-16 17:18:47.919177047 +0200
@@ -11359,6 +11359,9 @@ string_constant (tree arg, tree *ptr_off
       return array;
     }

+  if (varidx != NULL_TREE)
+    return NULL_TREE;
+
   if (!VAR_P (array) && TREE_CODE (array) != CONST_DECL)
     return NULL_TREE;