Fix rclone (scoop shim) and sftp issue due to detached console on Windows

changelog/unreleased/issue-3692

@@ -0,0 +1,12 @@
+Bugfix: Fix rclone (shimmed by Scoop) and sftp stopped working on Windows
+
+In #3602 a fix was introduced to fix the problem that rclone prematurely exits
+when Ctrl+C is pressed on Windows. The solution was to create the subprocess
+with its console detached from the restic console. However, such solution
+fails when using rclone install by scoop or using sftp with a passphrase-
+protected private key. We've fixed that by using a different approach to prevent
+Ctrl-C from passing down too early.
+
+https://github.com/restic/restic/issues/3681
+https://github.com/restic/restic/issues/3692
+https://github.com/restic/restic/pull/3696

internal/backend/foreground_windows.go

@@ -11,7 +11,7 @@ import (
 func startForeground(cmd *exec.Cmd) (bg func() error, err error) {
 	// just start the process and hope for the best
 	cmd.SysProcAttr = &syscall.SysProcAttr{}
-	cmd.SysProcAttr.CreationFlags = windows.DETACHED_PROCESS
+	cmd.SysProcAttr.CreationFlags = windows.CREATE_NEW_PROCESS_GROUP
 	err = cmd.Start()
 	if err != nil {
 		return nil, errors.Wrap(err, "cmd.Start")