I agree it's not a good idea to use a combination of both preferences. 
But ignoring one of the preference if both are set is even worth and 
too confusing.

We currently disable both prefs by default, so I think anybody 
enabling both settings explicitely should know what he is doing.

The sig_first and sig_dashes features creates problems when replying 
and forwarding messages.  Any mailreader (including Imp itself) that 
knows of the '-- ' convention will then treat the quoted text after 
the signature as part of the signature.  This is confusing for any 
recipients of such messages.  The solution is to only honor the 
sig_dashes flag if composing a new message or if the sig_first flag is 
not set.



The following patch is not tested, but should at least be a guide to a 
finished fix.





*** lib/Identity/IMP.php.org    Tue Aug 10 15:40:02 2004

--- lib/Identity/IMP.php        Tue Aug 10 19:09:38 2004

***************

*** 233,245 ****

           $val = $this->getValue('signature', $ident);



           if (isset($val)) {

               $sig_first = $this->getValue('sig_first', $ident);

-             $sig_dashes = $this->getValue('sig_dashes', $ident);

               $val = str_replace("\r\n", "\n", $val);

-             if ($sig_dashes) {

-                 $val = "-- \n$val";

-             }

               if (isset($sig_first) && $sig_first) {

                   $val = "\n" . $val . "\n\n\n";

               } else {

                   $val = "\n" . $val;

--- 233,241 ----





*** compose.php.org     Tue Aug 10 15:43:00 2004

--- compose.php Tue Aug 10 19:43:16 2004

***************

*** 1208,1222 ****

                                   
$identity->getValue('save_sent_mail', $ident));

   }

   $sig = $identity->getSignature();

   $sig_first = $identity->getValue('sig_first');



   if ($get_sig) {

       if (isset($msg) && !empty($sig)) {

!         if ($sig_first) {

               $msg  = "\n" . $sig . $msg;

           } else {

!             $msg .= "\n" . $sig;

           }

       }

   }



--- 1208,1229 ----

                                   
$identity->getValue('save_sent_mail', $ident));

   }

   $sig = $identity->getSignature();

   $sig_first = $identity->getValue('sig_first');

+ $sig_dashes = $identity->getValue('sig_dashes');

+

+ // Only honor sig_dashes if the signature is at the end, or the 
message is empty.



   if ($get_sig) {

       if (isset($msg) && !empty($sig)) {

!         if ($sig_first && !empty(trim($msg))) {

               $msg  = "\n" . $sig . $msg;

           } else {

!             if ($sig_dashes) {

!                 $msg .= "\n-- \n$" .sig;

!             } else {

!                 $msg .= "\n" . $sig;

!             }

           }

       }

   }