Handle /dev/null on linux, as an closed device.

runtime/bin/file_macos.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_MACOS)
 
 #include "bin/file.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 91 matching lines @@
     return st.st_size;
   }
   return -1;
 }
 
 
 File* File::Open(const char* name, FileOpenMode mode) {
   // Report errors for non-regular files.
   struct stat st;
   if (TEMP_FAILURE_RETRY(stat(name, &st)) == 0) {
-    if (!S_ISREG(st.st_mode)) {
+    // Only accept regular files and character devices.
+    if (!S_ISREG(st.st_mode) && !S_ISCHR(st.st_mode)) {
       errno = (S_ISDIR(st.st_mode)) ? EISDIR : ENOENT;
       return NULL;
     }
   }
   int flags = O_RDONLY;
   if ((mode & kWrite) != 0) {
     flags = (O_RDWR | O_CREAT);
   }
   if ((mode & kTruncate) != 0) {
     flags = flags | O_TRUNC;
@@ skipping 141 matching lines @@
     stat_success = TEMP_FAILURE_RETRY(lstat(pathname, &entry_info));
   }
   if (stat_success == -1) return File::kDoesNotExist;
   if (S_ISDIR(entry_info.st_mode)) return File::kIsDirectory;
   if (S_ISREG(entry_info.st_mode)) return File::kIsFile;
   if (S_ISLNK(entry_info.st_mode)) return File::kIsLink;
   return File::kDoesNotExist;
 }
 
 #endif  // defined(TARGET_OS_MACOS)