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 424 matching lines @@
         if (mb->tail == mb->bufsize)
             mb->tail = 0;
     } else if (bytes_read == 0) {
         /* Record EOF condition and report to caller when buffer runs dry */
         ((PRFilePrivate *)secret)->eof = PR_TRUE;
     } else /* if (bytes_read < 0) */ {
         mb->last_err = bytes_read;
     }
 }
 
-void memio_GetWriteParams(memio_Private *secret,
-                          const char **buf1, unsigned int *len1,
-                          const char **buf2, unsigned int *len2)
+int memio_GetWriteParams(memio_Private *secret,
+                         const char **buf1, unsigned int *len1,
+                         const char **buf2, unsigned int *len2)
 {
     struct memio_buffer* mb = &((PRFilePrivate *)secret)->writebuf;
     PR_ASSERT(mb->bufsize);
 
+    if (mb->last_err)
+        return mb->last_err;
+
     *buf1 = &mb->buf[mb->head];
     *len1 = memio_buffer_used_contiguous(mb);
     *buf2 = mb->buf;
     *len2 = memio_buffer_wrapped_bytes(mb);
+    return 0;
 }
 
 void memio_PutWriteResult(memio_Private *secret, int bytes_written)
 {
     struct memio_buffer* mb = &((PRFilePrivate *)secret)->writebuf;
     PR_ASSERT(mb->bufsize);
 
     if (bytes_written > 0) {
         mb->head += bytes_written;
         if (mb->head >= mb->bufsize)
@@ skipping 59 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