type n t;

was copying a bit too much about t into n,
like whether the signature was queued to be printed.
(bug reported by anton)

was also editing t, meaning you could do
	type T int;
	func (p int) Meth() { }

both fixed.

R=ken
OCL=27052
CL=27052

src/cmd/gc/dcl.c

@@ -91,6 +91,7 @@ void
 updatetype(Type *n, Type *t)
 {
 	Sym *s;
+	int local;
 
 	s = n->sym;
 	if(s == S || s->otype != n)
@@ -118,10 +119,19 @@ updatetype(Type *n, Type *t)
 		fatal("updatetype %T / %T", n, t);
 	}
 
-	if(n->local)
-		t->local = 1;
+	// decl was
+	//	type n t;
+	// copy t, but then zero out state associated with t
+	// that is no longer associated with n.
+	local = n->local;
 	*n = *t;
 	n->sym = s;
+	n->local = local;
+	n->siggen = 0;
+	n->methptr = 0;
+	n->printed = 0;
+	n->method = nil;
+	n->vargen = 0;
 
 	// catch declaration of incomplete type
 	switch(n->etype) {

src/cmd/gc/obj.c

@@ -425,6 +425,7 @@ dumpsignatures(void)
 		t = d->dtype;
 		et = t->etype;
 		s = signame(t);
+//print("signame %S for %T\n", s, t);
 		if(s == S)
 			continue;
 

src/cmd/gc/subr.c

@@ -1637,8 +1637,8 @@ signame(Type *t)
 		ss->oname->class = PEXTERN;
 	}
 
+//print("siggen %T %d\n", t, t->siggen);
 	if(!t->siggen) {
-//print("siggen %T\n", t);
 		// special case: don't generate the empty interface
 		if(strcmp(buf, "empty") == 0)
 			goto out;