os/exec: Wait behavior changed from Go 1.9 to Go 1.10 on Windows #25835
Description
Copying from #23019 (comment)
Here is the reproduction as a main function with correct markdown :-)
THX @ysmolsky!
Result does not change: works with go 1.9, breaks with go 1.10.
package main
import (
"bufio"
"context"
"fmt"
"os"
"os/exec"
"strings"
"syscall"
"time"
)
func fatal(format string, args ...interface{}) {
fmt.Println(fmt.Sprintf(format, args...))
os.Exit(1)
}
func main() {
ctx, cancel := context.WithTimeout(context.Background(), time.Second)
defer cancel()
cmd := exec.CommandContext(ctx, "sh", "-c", "echo hello world && sleep 5")
stdoutPipe, err := cmd.StdoutPipe()
if err != nil {
fatal("no pipe: %v", err)
}
start := time.Now()
if err = cmd.Start(); err != nil {
fatal("start failed: %v", err)
}
go func() {
var stdout string
buf := bufio.NewReader(stdoutPipe)
for {
line, err := buf.ReadString('\n')
if len(line) > 0 {
stdout = stdout + line + "\n"
}
if err != nil {
if !strings.HasPrefix(stdout, "hello world") {
fatal("wrong output: %q", stdout)
}
return
}
}
}()
err = cmd.Wait()
d := time.Since(start)
if err != nil {
exiterr := err.(*exec.ExitError)
status := exiterr.Sys().(syscall.WaitStatus)
if status.ExitStatus() == 0 {
fatal("wrong exit status: %v", status.ExitStatus())
}
}
if d.Seconds() >= 3 {
fatal("Cancelation took too long: %v", d)
}
fmt.Println("Success!")
}