diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 0049abf9ff0..c30348906ef 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,10 @@
+Mon Oct 20 10:52:22 1997  Jason Merrill  <jason@yorick.cygnus.com>
+
+	* decl.c (init_decl_processing): Give null_node unknown* type.
+	* typeck.c (comp_target_types): Handle UNKNOWN_TYPE.
+	(common_type): Likewise.
+	* error.c (args_as_string): Recognize null_node.
+
 Thu Oct 16 15:31:09 1997  Judy Goldberg <judygold@sanwafp.com>
 
 	* pt.c (determine_explicit_specialization): Initialize "dummy"
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 6f1007cda21..59fdbb32757 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -4998,11 +4998,6 @@ init_decl_processing ()
   TREE_TYPE (null_pointer_node) = build_pointer_type (void_type_node);
   layout_type (TREE_TYPE (null_pointer_node));
      
-  if (flag_ansi)
-    TREE_TYPE (null_node) = type_for_size (POINTER_SIZE, 0);
-  else
-    TREE_TYPE (null_node) = build_pointer_type (void_type_node);
-
   /* Used for expressions that do nothing, but are not errors.  */
   void_zero_node = build_int_2 (0, 0);
   TREE_TYPE (void_zero_node) = void_type_node;
@@ -5315,7 +5310,14 @@ init_decl_processing ()
   TYPE_MODE (unknown_type_node) = TYPE_MODE (void_type_node);
   /* Indirecting an UNKNOWN_TYPE node yields an UNKNOWN_TYPE node.  */
   TREE_TYPE (unknown_type_node) = unknown_type_node;
-  /* Looking up TYPE_POINTER_TO and TYPE_REFERENCE_TO yield the same result.  */
+
+  if (flag_ansi)
+    TREE_TYPE (null_node) = type_for_size (POINTER_SIZE, 0);
+  else
+    TREE_TYPE (null_node) = build_pointer_type (unknown_type_node);
+
+  /* Looking up TYPE_POINTER_TO and TYPE_REFERENCE_TO yield the same
+     result.  */
   TYPE_POINTER_TO (unknown_type_node) = unknown_type_node;
   TYPE_REFERENCE_TO (unknown_type_node) = unknown_type_node;
 
diff --git a/gcc/cp/error.c b/gcc/cp/error.c
index bec7bfaa1e4..5128175233f 100644
--- a/gcc/cp/error.c
+++ b/gcc/cp/error.c
@@ -1763,7 +1763,10 @@ args_as_string (p, v)
   OB_INIT ();
   for (; p; p = TREE_CHAIN (p))
     {
-      dump_type (error_type (TREE_VALUE (p)), v);
+      if (TREE_VALUE (p) == null_node)
+	OB_PUTS ("NULL");
+      else
+	dump_type (error_type (TREE_VALUE (p)), v);
       if (TREE_CHAIN (p))
 	OB_PUTS (", ");
     }
diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index d5d4381cbd8..aafea54b1e4 100644
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -451,6 +451,10 @@ common_type (t1, t2)
 	  target = tt1;
 	else if (tt1 == void_type_node || tt2 == void_type_node)
 	  target = void_type_node;
+	else if (tt1 == unknown_type_node)
+	  target = tt2;
+	else if (tt2 == unknown_type_node)
+	  target = tt1;
 	else
 	  target = common_type (tt1, tt2);
 
@@ -871,7 +875,10 @@ comp_target_types (ttl, ttr, nptrs)
 
       if (nptrs > 0)
 	{
-	  if (TREE_CODE (ttl) == VOID_TYPE
+	  if (TREE_CODE (ttl) == UNKNOWN_TYPE
+	      || TREE_CODE (ttr) == UNKNOWN_TYPE)
+	    return 1;
+	  else if (TREE_CODE (ttl) == VOID_TYPE
 		   && TREE_CODE (ttr) != FUNCTION_TYPE
 		   && TREE_CODE (ttr) != METHOD_TYPE
 		   && TREE_CODE (ttr) != OFFSET_TYPE)