From: Rob Findley <rfindley@google.com>
Date: Wed, 5 May 2021 19:01:37 +0000 (-0400)
Subject: go/types: fix potential bugs in santitizer pass
X-Git-Tag: go1.17beta1~233
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=543e098320;p=gostls13.git

go/types: fix potential bugs in santitizer pass

This is a port of CL 317329 to go/types.

Change-Id: I1ba65284c91044f0ceed536da4149ef25e1f9502
Reviewed-on: https://go-review.googlesource.com/c/go/+/317291
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
---

diff --git a/src/go/types/sanitize.go b/src/go/types/sanitize.go
index 3429867321..b905972d36 100644
--- a/src/go/types/sanitize.go
+++ b/src/go/types/sanitize.go
@@ -67,13 +67,17 @@ func sanitizeInfo(info *Info) {
 type sanitizer map[Type]Type
 
 func (s sanitizer) typ(typ Type) Type {
+	if typ == nil {
+		return nil
+	}
+
 	if t, found := s[typ]; found {
 		return t
 	}
 	s[typ] = typ
 
 	switch t := typ.(type) {
-	case nil, *Basic, *bottom, *top:
+	case *Basic, *bottom, *top:
 		// nothing to do
 
 	case *Array:
@@ -107,10 +111,14 @@ func (s sanitizer) typ(typ Type) Type {
 
 	case *Interface:
 		s.funcList(t.methods)
-		s.typ(t.types)
+		if types := s.typ(t.types); types != t.types {
+			t.types = types
+		}
 		s.typeList(t.embeddeds)
 		s.funcList(t.allMethods)
-		s.typ(t.allTypes)
+		if allTypes := s.typ(t.allTypes); allTypes != t.allTypes {
+			t.allTypes = allTypes
+		}
 
 	case *Map:
 		if key := s.typ(t.key); key != t.key {