PR c++/82760 - memory corruption with aligned new.

	* call.c (build_operator_new_call): Update *args if we add the
	align_arg.

From-SVN: r255253

gcc/cp/ChangeLog

+2017-11-29  Jason Merrill  <jason@redhat.com>
+
+	PR c++/82760 - memory corruption with aligned new.
+	* call.c (build_operator_new_call): Update *args if we add the
+	align_arg.
+
 2017-11-28  Jakub Jelinek  <jakub@redhat.com>
 
 	PR sanitizer/81275

gcc/cp/call.c

@@ -4372,6 +4372,8 @@ build_operator_new_call (tree fnname, vec<tree, va_gc> **args,
 	= vec_copy_and_insert (*args, align_arg, 1);
       cand = perform_overload_resolution (fns, align_args, &candidates,
 					  &any_viable_p, tf_none);
+      if (cand)
+	*args = align_args;
       /* If no aligned allocation function matches, try again without the
 	 alignment.  */
     }

gcc/testsuite/g++.dg/cpp1z/aligned-new8.C

+// PR c++/82760
+// { dg-options -std=c++17 }
+// { dg-do run }
+
+#include <new>
+#include <cstddef>
+
+struct alignas(2 * alignof (std::max_align_t)) aligned_foo {
+  char x[2048];
+
+  ~aligned_foo() { }
+  aligned_foo() { __builtin_memset(x, 0, sizeof(x)); }
+};
+
+int main()
+{
+  aligned_foo * gFoo = new (std::nothrow) aligned_foo[2];
+  delete[] gFoo;
+}