re PR c/71685 (Segmentation fault in gcc when compiling the attached file.)

	PR c/71685
	* c-typeck.c (c_build_qualified_type): Don't clear
	C_TYPE_INCOMPLETE_VARS for the main variant.

	* gcc.dg/pr71685.c: New test.

From-SVN: r237830

gcc/c/ChangeLog

+2016-06-29  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/71685
+	* c-typeck.c (c_build_qualified_type): Don't clear
+	C_TYPE_INCOMPLETE_VARS for the main variant.
+
 2016-06-28  Martin Sebor  <msebor@redhat.com>
 
 	PR c/71552

gcc/c/c-typeck.c

@@ -13676,7 +13676,8 @@ c_build_qualified_type (tree type, int type_quals, tree orig_qual_type,
 		   : build_qualified_type (type, type_quals));
   /* A variant type does not inherit the list of incomplete vars from the
      type main variant.  */
-  if (RECORD_OR_UNION_TYPE_P (var_type))
+  if (RECORD_OR_UNION_TYPE_P (var_type)
+      && TYPE_MAIN_VARIANT (var_type) != var_type)
     C_TYPE_INCOMPLETE_VARS (var_type) = 0;
   return var_type;
 }

gcc/testsuite/ChangeLog

+2016-06-29  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/71685
+	* gcc.dg/pr71685.c: New test.
+
 2016-06-28  Martin Sebor  <msebor@redhat.com>
 
 	PR c/71552

gcc/testsuite/gcc.dg/pr71685.c

+/* PR c/71685 */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu11" } */
+
+extern struct S v, s;
+struct S { int t; int p[]; } v = { 4, 0 };