time: Time.String formats negative monotonic times incorrectly #18993
Description
Please answer these questions before submitting your issue. Thanks!
What version of Go are you using (go version)?
tip (go version devel +0c9325e Wed Feb 8 17:54:06 2017 +0000 linux/amd64)
What operating system and processor architecture are you using (go env)?
linux/amd64
What did you do?
package main
import (
"fmt"
"time"
)
func main() {
time.Sleep(200 * time.Millisecond)
t := time.Now()
fmt.Println(t)
t = t.Add(-time.Second)
fmt.Println(t)
}
This printed
2017-02-08 10:34:35.543437741 -0800 PST m=+0.200282679
2017-02-08 10:34:34.543437741 -0800 PST m=-1.200282679
Given the first timestamp, the second line should instead have been
2017-02-08 10:34:34.543437741 -0800 PST m=-0.799717321
Looks like that method could also use a test. If it's OK, I'll send a CL.
/cc @rsc