From: Robert Griesemer <gri@golang.org>
Date: Tue, 12 Nov 2024 22:14:19 +0000 (-0800)
Subject: go/types: adjust type-checking of pointer types
X-Git-Tag: go1.24rc1~416
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=5e91059f8b5cc078b4b0bfa38290a98414e441e2;p=gostls13.git

go/types: adjust type-checking of pointer types

This matches the behavior of types2.

For #49005.

Change-Id: I45661c96124f1c75c4fb6f69cbba7c73984a8231
Reviewed-on: https://go-review.googlesource.com/c/go/+/626039
Auto-Submit: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
---

diff --git a/src/go/types/typexpr.go b/src/go/types/typexpr.go
index c83f53ba61..0b88f31d73 100644
--- a/src/go/types/typexpr.go
+++ b/src/go/types/typexpr.go
@@ -334,6 +334,13 @@ func (check *Checker) typInternal(e0 ast.Expr, def *TypeName) (T Type) {
 		typ.base = Typ[Invalid] // avoid nil base in invalid recursive type declaration
 		setDefType(def, typ)
 		typ.base = check.varType(e.X)
+		// If typ.base is invalid, it's unlikely that *base is particularly
+		// useful - even a valid dereferenciation will lead to an invalid
+		// type again, and in some cases we get unexpected follow-on errors
+		// (e.g., go.dev/issue/49005). Return an invalid type instead.
+		if !isValid(typ.base) {
+			return Typ[Invalid]
+		}
 		return typ
 
 	case *ast.FuncType: