mountlib: make tests work under all platforms

cmd/mountlib/mounttest/write.go

@@ -1,10 +1,7 @@
-// +build linux darwin freebsd
-
 package mounttest
 
 import (
 	"os"
-	"syscall"
 	"testing"
 	"time"
 
@@ -68,45 +65,6 @@ func TestWriteFileOverwrite(t *testing.T) {
 	run.rm(t, "testwrite")
 }
 
-// Test double close
-func TestWriteFileDoubleClose(t *testing.T) {
-	run.skipIfNoFUSE(t)
-
-	out, err := os.Create(run.path("testdoubleclose"))
-	assert.NoError(t, err)
-	fd := out.Fd()
-
-	fd1, err := syscall.Dup(int(fd))
-	assert.NoError(t, err)
-
-	fd2, err := syscall.Dup(int(fd))
-	assert.NoError(t, err)
-
-	// close one of the dups - should produce no error
-	err = syscall.Close(fd1)
-	assert.NoError(t, err)
-
-	// write to the file
-	buf := []byte("hello")
-	n, err := out.Write(buf)
-	assert.NoError(t, err)
-	assert.Equal(t, 5, n)
-
-	// close it
-	err = out.Close()
-	assert.NoError(t, err)
-
-	// write to the other dup - should produce an error
-	n, err = syscall.Write(fd2, buf)
-	assert.Error(t, err, "input/output error")
-
-	// close the dup - should produce an error
-	err = syscall.Close(fd2)
-	assert.Error(t, err, "input/output error")
-
-	run.rm(t, "testdoubleclose")
-}
-
 // Test Fsync
 //
 // NB the code for this is in file.go rather than write.go