Prevent negative offsets when paginating collection

[tautvydasr]

Recently I faced a problem with collection pagination because it calculates negative offset and returns entries from the end of collection items.

For example:

$c = new Collection(['one', 'two', 'three', 'four']);
$c->forPage(0, 2)->all() // returns ['three', 'four']

I believe it would be nice if offset could not be negative and only positive numbers could be accepted as page.

[taylorotwell]

Send to 5.5 branch.

[sisve]

@tautvydasr This break other applications that rely on this behavior, Most things in PHP has the ability to use negative values to start at "the other end", like substr with a negative start value will count from the end of the string.

[deleugpn]

@sisve looks like Taylor wanted this on point release.

[tautvydasr]

@taylorotwell moved to 5.5 branch #21658

@sisve PHP ability to use negative values to start at "the other end" should be used with slice method which is using native function array_slice and this behavior is expected. Method forPage is supposed to only paginate collection items so negative offset behavior is not expected. I don't think there is a real world example where page number is supposed to be for instance -2.