mirror of
https://github.com/golang/go
synced 2024-11-12 07:40:23 -07:00
09834d1c08
A straight conversion from a type T to an interface type I, where T does not implement I, should always panic with an interface conversion error that shows the missing method. This was not happening if the conversion was done once using the comma-ok form (the result would not be OK) and then again in a straight conversion. Due to an error in the runtime package the second conversion was failing with a nil pointer dereference. Fixes #16130. Change-Id: I8b9fca0f1bb635a6181b8b76de8c2385bb7ac2d2 Reviewed-on: https://go-review.googlesource.com/24284 Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Michel Lespinasse <walken@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Andrew Gerrand <adg@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
44 lines
947 B
Go
44 lines
947 B
Go
// run
|
|
|
|
// Copyright 2016 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// Test that an interface conversion error panics with an "interface
|
|
// conversion" run-time error. It was (incorrectly) panicing with a
|
|
// "nil pointer dereference."
|
|
|
|
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"runtime"
|
|
"strings"
|
|
)
|
|
|
|
type I interface {
|
|
Get() int
|
|
}
|
|
|
|
func main() {
|
|
defer func() {
|
|
r := recover()
|
|
if r == nil {
|
|
panic("expected panic")
|
|
}
|
|
re, ok := r.(runtime.Error)
|
|
if !ok {
|
|
panic(fmt.Sprintf("got %T, expected runtime.Error", r))
|
|
}
|
|
if !strings.Contains(re.Error(), "interface conversion") {
|
|
panic(fmt.Sprintf("got %q, expected interface conversion error", re.Error()))
|
|
}
|
|
}()
|
|
e := (interface{})(0)
|
|
if _, ok := e.(I); ok {
|
|
panic("unexpected interface conversion success")
|
|
}
|
|
fmt.Println(e.(I))
|
|
panic("unexpected interface conversion success")
|
|
}
|