Fix crash when an SSL key-log file couldn't be opened.

net/third_party/nss/ssl/sslsock.c

 /*
  * vtables (and methods that call through them) for the 4 types of 
  * SSLSockets supported.  Only one type is still supported.
  * Various other functions.
  *
  * ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (the "License"); you may not use this file except in compliance with
@@ skipping 2916 matching lines @@
 #endif /* TRACE */
         ev = getenv("SSLDEBUG");
         if (ev && ev[0]) {
             ssl_debug = atoi(ev);
             SSL_TRACE(("SSL: debugging set to %d", ssl_debug));
         }
 #endif /* DEBUG */
         ev = getenv("SSLKEYLOGFILE");
         if (ev && ev[0]) {
             ssl_keylog_iob = fopen(ev, "a");
-            if (ftell(ssl_keylog_iob) == 0) {
-                fputs("# SSL/TLS secrets log file, generated by NSS\n",
-                      ssl_keylog_iob);
+            if (!ssl_keylog_iob) {
+                SSL_TRACE(("Failed to open key log file"));
+            } else {
+                if (ftell(ssl_keylog_iob) == 0) {
+                    fputs("# SSL/TLS secrets log file, generated by NSS\n",
+                          ssl_keylog_iob);
+                }
+                SSL_TRACE(("SSL: logging pre-master secrets to %s", ev));
             }
-            SSL_TRACE(("SSL: logging pre-master secrets to %s", ev));
         }
         ev = getenv("SSLBYPASS");
         if (ev && ev[0]) {
             ssl_defaults.bypassPKCS11 = (ev[0] == '1');
             SSL_TRACE(("SSL: bypass default set to %d", \
                       ssl_defaults.bypassPKCS11));
         }
         ev = getenv("SSLFORCELOCKS");
         if (ev && ev[0] == '1') {
             ssl_force_locks = PR_TRUE;
@@ skipping 110 matching lines @@
             ssl_DestroySocketContents(ss);
             ssl_DestroyLocks(ss);
             PORT_Free(ss);
             ss = NULL;
         }
         ss->protocolVariant = protocolVariant;
     }
     return ss;
 }