go/types: return Universe for (*Package)(nil).Scope()

Port of go.dev/cl/325469.

Fixes #46594.

Change-Id: I4bcdafecaa86885360599c204678871646bb221b
Reviewed-on: https://go-review.googlesource.com/c/go/+/385997
Trust: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>

diff --git a/src/go/types/package.go b/src/go/types/package.go
index 7b89def1b5d5137c5572131cf336cb12f97e3257..26385dc39b95fbe41b382f1477cb8f00af5f807c 100644 (file)
--- a/src/go/types/package.go
+++ b/src/go/types/package.go
@@ -39,7 +39,13 @@ func (pkg *Package) SetName(name string) { pkg.name = name }
 // Scope returns the (complete or incomplete) package scope
 // holding the objects declared at package level (TypeNames,
 // Consts, Vars, and Funcs).
-func (pkg *Package) Scope() *Scope { return pkg.scope }
+// For a nil pkg receiver, Scope returns the Universe scope.
+func (pkg *Package) Scope() *Scope {
+       if pkg != nil {
+               return pkg.scope
+       }
+       return Universe
+}
 
 // A package is complete if its scope contains (at least) all
 // exported objects; otherwise it is incomplete.