bug161, fixed

R=ken
OCL=29907
CL=29907

src/cmd/gc/dcl.c

@@ -956,6 +956,8 @@ addvar(Node *n, Type *t, int ctxt)
 	s->vargen = gen;
 	s->oname = n;
 	s->offset = 0;
+	s->oconst = nil;
+	s->otype = nil;
 	s->lexical = LNAME;
 
 	n->funcdepth = funcdepth;
@@ -1003,6 +1005,8 @@ addtyp(Type *n, int ctxt)
 
 	redeclare("type", s);
 	s->otype = n;
+	s->oconst = nil;
+	s->oname = nil;
 	s->lexical = LATYPE;
 
 	d = dcl();
@@ -1056,6 +1060,8 @@ addconst(Node *n, Node *e, int ctxt)
 
 	redeclare("constant", s);
 	s->oconst = e;
+	s->otype = nil;
+	s->oname = nil;
 	s->lexical = LNAME;
 
 	d = dcl();

src/cmd/gc/subr.c

@@ -1045,7 +1045,7 @@ Tpretty(Fmt *fp, Type *t)
 			else
 				fmtprint(fp, "%lS", s);
 			if(strcmp(s->package, package) == 0)
-			if(s->otype != t || (!s->export && !s->imported)) {
+			if((s->otype != t || !s->export) && !s->imported) {
 				fmtprint(fp, "·%s", filename);
 				if(t->vargen)
 					fmtprint(fp, "·%d", t->vargen);

test/fixedbugs/bug161.go

+// $G $D/$F.go || echo BUG: should compile
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package P
+
+const a = 0;
+
+func f(a int) {
+	a = 0;
+}
+
+/*
+bug161.go:8: operation LITERAL not allowed in assignment context
+*/