--- /dev/null
+package main
+
+import "fmt"
+
+type S struct{}
+
+func (s *S) Error() string {
+ return "error for S"
+}
+
+func structNil() *S {
+ return nil
+}
+
+func errorNil() error {
+ return nil
+}
+
+func main() {
+ err := errorNil()
+ fmt.Println(err != nil)
+ err = structNil()
+ fmt.Println(err != nil) // want `this comparison is always true`
+ err = errorNil()
+ fmt.Println(err != nil)
+}