avoid ssl_eof error on SSL_WANT_READ and friends

Incrementing a counter on empty SSL reads is not the correct way to determine
ssl_eof
(http://code.sixapart.com/trac/djabberd/changeset/758)

Instead we should check the error code to see if it is one of the SSL errors for
which we are supposed to retry(
http://www.openssl.org/docs/ssl/SSL_get_error.html)

[bradfitz]

http://codereview.appspot.com/2341/diff/1/2
File lib/DJabberd/Stanza/StartTLS.pm (right):

http://codereview.appspot.com/2341/diff/1/2#newcode74
Line 74: my $err = Net::SSLeay::get_error($ssl,-1);
space after comma

http://codereview.appspot.com/2341/diff/1/2#newcode85
Line 85: return $err;
Does this function return a boolean or an error code?  The name suggests a
boolean, but the return value suggests an error code.

[Jacob]

I've uploaded a new patch

http://codereview.appspot.com/2341/diff/1/2
File lib/DJabberd/Stanza/StartTLS.pm (right):

http://codereview.appspot.com/2341/diff/1/2#newcode74
Line 74: my $err = Net::SSLeay::get_error($ssl,-1);
On 2008/06/19 20:45:39, bradfitz wrote:
> space after comma

Done.

http://codereview.appspot.com/2341/diff/1/2#newcode85
Line 85: return $err;
On 2008/06/19 20:45:39, bradfitz wrote:
> Does this function return a boolean or an error code?  The name suggests a
> boolean, but the return value suggests an error code.
> 

Both! It returns an error code or zero, and the return value is used as if it
were a boolean in the if check in Connection to decide if we should close or not
close.  If we should close, we want to log the error code, so we log the value
returned.... I've changed the function name to actual_error_on_empty_read, is
that better?  Open to suggestions.

[bradfitz]

http://codereview.appspot.com/2341/diff/61/82
File lib/DJabberd/Connection.pm (right):

http://codereview.appspot.com/2341/diff/61/82#newcode495
Line 495: # A call to 'should_we_close_on_zero_bytes' accounts for the
possibility
You didn't update this comment.

Otherwise this seems fine now, assuming you've tested it all.  See
http://danga.com/commit.bml and let's get you commit access.