10.x: a predicate over a null range, RangeSet or value set is false in memory and in SQL (port of the predicate half of #350, #355 and #356) #357

Problem

#350, #355 and #356 apply to release/10.x (10.1.0) unchanged. RangeExtensions.cs is identical on both lines, and the SQL measured for #355 is identical on EF Core 10.0.0 and on 10.0.13 with Npgsql 10.0.3.

Change (10.2.0)

The predicate half of rule (c) from #350, which only changes answers and so fits a minor under ### Changed answers:

• SQL (A predicate over a NULL range, RangeSet or value set column is NULL in SQL, so its negation drops the row EF Core's own translations keep #355): every Boolean predicate over a range, RangeSet or value set operand that can be NULL is written x IS NOT NULL AND <predicate>. The exception is CompareTo against 0 or ±1, which keeps A NULL range column now matches CompareTo(null) > 0 in a query; Comparer treats null vs null as equal #261's documented Comparer<T>.Default rule; equality stays EF Core's own. The SQL over required columns and non-null parameters stays the same.
• Memory, range extensions with a null range on either side. Measured 2026-10-24, DateRange against Empty, (,), a finite range, an element, {p} and {}:
  • true → false (changed answers): Contains(Empty), Contains(RangeSet.Empty) and IsContainedBy((,)) on a null range.
  • NullReferenceException → false: Contains(T) on a null range. With a non-empty RangeSet operand, Overlaps, IsAdjacentTo and IsContainedBy on a null range. And every predicate whose RangeSet argument is null (p.Contains(null), p.Overlaps(null), p.IsStrictlyLeftOf(null), …).
  • Already false, unchanged: IsEmpty, IsFinite, IsInfinity, IsUnboundedStart, IsUnboundedEnd, LowerBoundInclusive and UpperBoundInclusive. Also, with a range operand on either side, Overlaps, IsAdjacentTo, the four position operators, and Contains and IsContainedBy apart from the two rows above.
• RangeSet.From (RangeSet.From accepts a null element: the set holds null, IsEmpty() is false and Contains throws #356, PR fix: a range set refuses a null range instead of storing it #370): throws ArgumentException for a null element, as the value sets do. So Except and Union on a null range throw ArgumentException too. Today they build a set holding null or throw, and null.Union((,)) returns {(,)}. fix: a range set refuses a null range instead of storing it #370 removes A null range answers some extensions in memory and throws on others, and the answers it gives disagree with PostgreSQL on a NULL column #350's Union(Infinite).Contains(v) candidate for that reason, and the port removes it on 10.x.

Left as they are on 10.x, documented in docs/ranges.md and docs/efcore.md as undefined on a null range and throwing from 11.0.0:

• Intersect (returns Empty);
• Gap(Empty) (returns Empty); Gap with any other operand already throws;
• Merge(Empty) (returns null through a non-nullable return type) and Merge((,)) (returns (,)); Merge with any other operand already throws.

Four of #350's twelve candidates therefore stay registered on 10.x: Intersect(p) != null, Intersect(p) == Empty, Gap(Empty).IsEmpty() and Merge(Infinite) == x. Union(Infinite).Contains(v) is fixed by #356, because memory throws for it.

Changelog: one ### Changed answers row per issue in [10.2.0], linking it and its docs/migration.md#changed-answers-in-1020 entry, in all the package changelogs it affects. Needs #331 to open 10.2.0 first.

Done when

On release/10.x, the widened #355 sweep passes on PostgreSQL 16 and 18 with only those four candidates left. The in-memory rows above are pinned by a test that fails with each change reverted. Close by hand after the merge.