%delta is not a linear "linked list"

[perlancar]

Bummer, turns out that due to multiple branches of perl (e.g. even minor version for stable branch and odd for development branch), we cannot simply iterate %delta by sorted key (release version). For example, $delta{'5.017'} is data against 5.016, not against the latest 5.016 release (5.016003).

Because Module::CoreList::More's functions iterate %delta in a single pass (wrongly assuming it was a linear "linked list") they can give wrong result, for example:

Module::CoreList->is_core("Module::CoreList", 2.76, 5.017) # returns false

but

Module::CoreList::More->is_core("Module::CoreList", 2.76, 5.017) # returns true, which is wrong

This is because, Module::CoreList was updated to 2.76 in perl 5.01602. Meanwhile, perl 5.17 still contains Module::CoreList 2.67. Because Module::CoreList::More iterates %delta by release version, it processes 5.017 after 5.01602 and 5.01603. When it should've processed 5.017 after 5.016.

To keep the performance advantage, one solution for this is, I think, is to create another data structure, e.g. %delta_sorted_by_release which contains the delta data sorted by release version. So we can still iterate the structure in a single pass. Also, if we do this, another optimization (early loop exit) also cannot be done because the assumption that module version monotonically increases as release version increases no longer holds (or to be exact, never holds anyway).

[perlancar]

Fixed by 323bd90