This closes bug #453335

src/compose.php

@@ -444,7 +444,8 @@
 	 $body = explode("\n", $body);
 	 $newBody = '';
 	 foreach ($body as $line) {
-	    $line = rtrim($line);
+	    if( $line <> '-- ' )
+	       $line = rtrim($line);
 	    if (strlen($line) <= $editor_size + 1)
 	       $newBody .= $line . "\n";
 	    else {

src/options_personal.php

@@ -103,7 +103,7 @@
    if ( $prefix_sig )
      echo ' checked';
    echo '>  ' .
-        _( "Prefix signature with '--' ?" ) . '<BR>';
+        _( "Prefix signature with '-- ' ?" ) . '<BR>';
    echo "\n<textarea name=\"signature_edit\" rows=\"5\" cols=\"50\">$signature_abs</textarea><br>";
 ?>
             </td>