Merge "database: Add extra sanity check to selectFieldValues()"

diff --cc includes/db/Database.php
index d741b2f,98473a5..351d438
--- 1/includes/db/Database.php
--- 2/includes/db/Database.php
+++ b/includes/db/Database.php
@@@ -1066,10 -1066,12 +1066,12 @@@ abstract class DatabaseBase implements 
        }
  
        public function selectFieldValues(
 -              $table, $var, $cond = '', $fname = __METHOD__, $options = array(), $join_conds = array()
 +              $table, $var, $cond = '', $fname = __METHOD__, $options = [], $join_conds = []
        ) {
                if ( $var === '*' ) { // sanity
-                       throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
+                       throw new DBUnexpectedError( $this, "Cannot use a * field" );
+               } elseif ( !is_string( $var ) ) { // sanity
+                       throw new DBUnexpectedError( $this, "Cannot use an array of fields" );
                }
  
                if ( !is_array( $options ) ) {