os: handle 'no parent' error as IsNotExist on Plan 9

This error is returned by lib9p when removing a file
without parent. It should fix TestRemoveAllRace
when running on ramfs.

LGTM=bradfitz, aram
R=rsc, bradfitz, aram
CC=golang-codereviews, mischief
https://golang.org/cl/153410044

diff --git a/src/os/error_plan9.go b/src/os/error_plan9.go
index 45cd74792348f2149ebc29f14750c6eca9022d21..001cdfcf2e3376aed7273ddbd1a28c7b663b7995 100644 (file)
--- a/src/os/error_plan9.go
+++ b/src/os/error_plan9.go
@@ -25,7 +25,8 @@ func isNotExist(err error) bool {
        case *LinkError:
                err = pe.Err
        }
-       return contains(err.Error(), "does not exist") || contains(err.Error(), "not found") || contains(err.Error(), "has been removed")
+       return contains(err.Error(), "does not exist") || contains(err.Error(), "not found") ||
+               contains(err.Error(), "has been removed") || contains(err.Error(), "no parent")
 }
 
 func isPermission(err error) bool {