[Dovecot] Panic: pop3-login: file sasl-server.c: line 75 (authenticate_callback): assertion failed: (client->auth_request == request)

[Mike Abbott]

Running Dovecot-1.1.5, I see this assertion failure:
Panic: pop3-login: file sasl-server.c: line 75  
(authenticate_callback): assertion failed: (client->auth_request ==  
request)
Error: pop3-login: Raw backtrace:
  2   pop3-login                          0x000000010000ac41  
default_fatal_finish + 41 ->
  3   pop3-login                          0x000000010000acac  
i_syslog_fatal_handler + 0 ->
  4   pop3-login                          0x000000010000a446 i_info +  
0 ->
  5   pop3-login                          0x00000001000053a2  
authenticate_callback + 126 ->
  6   pop3-login                          0x000000010000841c  
auth_client_input_fail + 280 ->
  7   pop3-login                          0x0000000100007910  
auth_client_input + 358 ->
  8   pop3-login                          0x000000010000e074  
io_loop_handler_run + 272 ->
  9   pop3-login                          0x000000010000d449  
io_loop_run + 38 ->
10  pop3-login                          0x0000000100004864 main + 1572  
->
11  pop3-login                          0x00000001000012fc start + 52
Error: child 1302 (login) killed with signal 6

This happens when I feed multiple user/pass lines to Dovecot all at  
once like this:
$ telnet gromit 110
Connected.
Escape character is '^]'.
+OK Dovecot ready.
user x
pass y
user x
pass y
+OK
+OK
Connection closed by foreign host.

The four user/pass lines I pasted in all at once.

IMAP login does not crash when presented with multiple login commands,  
but it does not read them all at once and needs prodding (in the form  
of extra command lines sent later on) to read them.  Actually it  
appears to read the first two lines then stops reading until more data  
comes in:

$ telnet gromit 143
Connected.
Escape character is '^]'.
* OK Dovecot ready.
a login a b
b login c d
c login e f
d login g h
e login i j
a NO Authentication failed.
b NO Authentication failed.

c NO Authentication failed.

d NO Authentication failed.

e NO Authentication failed.

* BAD Error in IMAP command received by server.
* BAD Error in IMAP command received by server.
* BAD Error in IMAP command received by server.
* BAD Error in IMAP command received by server.
^]
telnet> q
Connection closed.

You probably don't care about the odd imap-login behavior, but I tried  
it and mentioned it just for completeness after seeing pop3-login crash.