panic (nil pointer dereference) in s3manager.Error.Error() when origErr is nil

[caseylucas]

Version of AWS SDK for Go?

v1.12.67

Version of Go (go version)?

go version go1.9.2 darwin/amd64

What issue did you see?

panic because of nil pointer dereference

panic(0xa952c0, 0xf29dd0)
        /usr/local/Cellar/go/1.9.2/libexec/src/runtime/panic.go:491 +0x283
github.com/aws/aws-sdk-go/service/s3/s3manager.(*Error).Error(0xc420537148, 0xc4201c2fc0, 0xc420363080)
        /Users/clucas/go/src/github.com/aws/aws-sdk-go/service/s3/s3manager/batch.go:63 +0x33

Steps to reproduce

If you have have an runnable example, please include it.

package main

import (
	"fmt"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/service/s3/s3manager"
)

func main() {
	fmt.Println("in main")
	err := s3manager.Error{
		Bucket: aws.String("bucket"),
		Key:    aws.String("key"),
	}
	fmt.Println(err.Error()) // <-- panic here
	/*
		panic: runtime error: invalid memory address or nil pointer dereference
		[signal SIGSEGV: segmentation violation code=0x1 addr=0x20 pc=0x126d693]

		goroutine 1 [running]:
		github.com/aws/aws-sdk-go/service/s3/s3manager.(*Error).Error(0xc420197f50, 0xc4200111d0, 0x1)
			/Users/clucas/go/src/github.com/aws/aws-sdk-go/service/s3/s3manager/batch.go:63 +0x33
		main.main()
		...
	*/
}

[jasdel]

Thanks for finding and letting us know about this bug @caseylucas. I'll take a look at the PR you created.

[jasdel]

Thanks for putting this PR together @caseylucas, we've merged in the fix.