Stop attempting to write to transport sockets in NSS on failure.

net/base/nss_memio.c

 // Copyright (c) 2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // Written in NSPR style to also be suitable for adding to the NSS demo suite
 
 /* memio is a simple NSPR I/O layer that lets you decouple NSS from
  * the real network.  It's rather like openssl's memory bio,
  * and is useful when your app absolutely, positively doesn't
  * want to let NSS do its own networking.
  */
@@ skipping 451 matching lines @@
 
     if (bytes_written > 0) {
         mb->head += bytes_written;
         if (mb->head >= mb->bufsize)
             mb->head -= mb->bufsize;
     } else if (bytes_written < 0) {
         mb->last_err = bytes_written;
     }
 }
 
+int memio_LastWriteError(memio_Private *secret)
+{
+    struct memio_buffer* mb = &((PRFilePrivate *)secret)->writebuf;
+    PR_ASSERT(mb->bufsize);
+
+    return mb->last_err;
+}
+
 /*--------------- private memio_buffer self-test -----------------*/
 
 /* Even a trivial unit test is very helpful when doing circular buffers. */
 /*#define TRIVIAL_SELF_TEST*/
 #ifdef TRIVIAL_SELF_TEST
 #include <stdio.h>
 
 #define TEST_BUFLEN 7
 
 #define CHECKEQ(a, b) { \
@@ skipping 43 matching lines @@
     CHECKEQ(memio_buffer_unused_contiguous(&mb), 0);
     CHECKEQ(memio_buffer_used_contiguous(&mb), 1);
 
     /* TODO: add more cases */
 
     printf("Test passed\n");
     exit(0);
 }
 
 #endif