If an option was not sent to options.php, pass null to update_option(), rather than trimming the null and converting it to an empty string. This provides better context for sanitize_option() while still storing what ends up being an empty string either way. see #16416.

git-svn-id: http://core.svn.wordpress.org/trunk@21849 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/options.php

@@ -141,11 +141,12 @@ if ( 'update' == $action ) {
 
 			$option = trim( $option );
 			$value = null;
-			if ( isset($_POST[$option]) )
+			if ( isset( $_POST[ $option ] ) ) {
 				$value = $_POST[ $option ];
 				if ( ! is_array( $value ) )
 					$value = trim( $value );
 				$value = stripslashes_deep( $value );
+			}
 			update_option( $option, $value );
 		}
 	}