re PR c++/71826 (ICE on valid C++ code with ambiguous member lookup: tree check:…

re PR c++/71826 (ICE on valid C++ code with ambiguous member lookup: tree check: expected baselink, have error_mark in tsubst_baselink, at cp/pt.c:13737)

	PR c++/71826
	* pt.c (tsubst_baselink): Only set BASELINK_OPTYPE for BASELINK_P.

	* g++.dg/template/pr71826.C: New test.

From-SVN: r238441

gcc/cp/ChangeLog

 2016-07-18  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/71826
+	* pt.c (tsubst_baselink): Only set BASELINK_OPTYPE for BASELINK_P.
+
 	PR c++/71822
 	* cp-gimplify.c (cp_gimplify_expr) <case VEC_INIT_EXPR>: Recursively
 	fold *expr_p before genericizing it.

gcc/cp/pt.c

@@ -13767,7 +13767,8 @@ tsubst_baselink (tree baselink, tree object_type,
 		  BASELINK_FUNCTIONS (baselink),
 		  template_args);
     /* Update the conversion operator type.  */
-    BASELINK_OPTYPE (baselink) = optype;
+    if (BASELINK_P (baselink))
+      BASELINK_OPTYPE (baselink) = optype;
 
     if (!object_type)
       object_type = current_class_type;

gcc/testsuite/ChangeLog

 2016-07-18  Jakub Jelinek  <jakub@redhat.com>
 
+	PR c++/71826
+	* g++.dg/template/pr71826.C: New test.
+
 	PR c++/71822
 	* g++.dg/template/defarg21.C: New test.
 

gcc/testsuite/g++.dg/template/pr71826.C

+// PR c++/71826
+// { dg-do compile }
+
+template <class> struct A { int i; };	// { dg-message "note" }
+struct B { void i () {} };		// { dg-message "note" }
+template <class T> struct C : A <T>, B
+{ 
+  void f () { i (); }			// { dg-error "is ambiguous" }
+};
+
+int
+main ()
+{ 
+  C <int> c;
+  c.f ();
+  return 0;
+}