internal/lsp/source: handle possible nil pointer in rename check

Change-Id: I92cc4015361d40e8a10d05fa6857bee2b302cec4
Reviewed-on: https://go-review.googlesource.com/c/tools/+/284583
Trust: Rebecca Stambler <[email protected]>
Run-TryBot: Rebecca Stambler <[email protected]>
gopls-CI: kokoro <[email protected]>
TryBot-Result: Go Bot <[email protected]>
Reviewed-by: Heschi Kreinick <[email protected]>

Author: stamblerre

internal/lsp/source/rename_check.go

@@ -894,6 +894,9 @@ func tokenFileContainsPos(f *token.File, pos token.Pos) bool {
 }
 
 func objectKind(obj types.Object) string {
+	if obj == nil {
+		return "nil object"
+	}
 	switch obj := obj.(type) {
 	case *types.PkgName:
 		return "imported package name"
@@ -937,6 +940,9 @@ func isLocal(obj types.Object) bool {
 }
 
 func isPackageLevel(obj types.Object) bool {
+	if obj == nil {
+		return false
+	}
 	return obj.Pkg().Scope().Lookup(obj.Name()) == obj
 }