Fix default sort order in Query Builder

[gerryvdm]

cursor.sort() expects a value of 1 for ascending or -1 for descending. Calling Builder::sort($field) would result in a sort with a value of 0.

Resorting to a default ascending order when not having specified a sort order.

[jmikola]

@gerryvdm: I think proper behavior here would be to throw an InvalidArgumentException, as the method should either be called with either a single array of field/order pairs or two field and order arguments. I'm not keen on defaulting to a particular order based because a required (by the documentation) argument is missing.

Something like "Single field requires an order argument" as the exception message would suffice, if you'd like to revise this.

[gerryvdm]

Wouldn't throwing an exception break a lot of exisiting code in projects?

I also don't think it's unreasonable to have a default ascending sort order?

[jmikola]

@gerryvdm: Good point on BC. I didn't consider that.

It looks like doctrine/dbal also defaults to ascending mode if the $order parameter is omitted, so this seems like a suitable default behavior.

[jmikola]

Manually merged. Thanks!