Bug #20725: Inconsistent handling of doubly-unbounded ranges in Range#overlap?

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 3.3.5 (2024-09-03 revision ef084cc8f4) [arm64-darwin23]
• Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN

[jeromepl (Jerome Parent-Levesque)]

The new Range#overlap? method does not seem to have a clear definition of how it behaves when passed ranges with nil begin and end (nil..).

In the following two cases, it seems to treat this type of range as an "infinite" range that covers the entire space and therefore overlaps with anything:

(nil..nil).overlap?(nil..) # => true
(nil..nil).overlap?(3..) # => true

However it behaves differently in this case:

(nil..nil).overlap?(..3) # => false

Note that this also behaves differently than the ActiveSupport implementation of #overlap? in a Ruby version < 3.3 such as 3.2:

require "active_support"
(nil..nil).overlap?(..3) # => true

I think (nil..nil) ranges should always be considered to be completely unbounded, i.e. infinite and covering the whole space. They should therefore always return true when overlapping with any non-empty range.

[nobu (Nobuyoshi Nakada)]

https://github.com/ruby/ruby/pull/11609

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset git|24493779b79bb57fd2e71bf6e0ababe95448a9d6.

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[Bug #20725] Should not call compare on nil-endpoint

It means unbounded, always inclusive of other ranges.