https://issues.dlang.org/show_bug.cgi?id=24342

          Issue ID: 24342
           Summary: T[][].until(T[]) breaks if sentinel is longer than 1.
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: major
          Priority: P1
         Component: phobos
          Assignee: nobody@puremagic.com
          Reporter: default_357-line@yahoo.de

import std;

void main()
{
    int[] marker = [2, 3];
    int[][] first = [[1], [2, 3], [4]];
    int[][] second = first.until(marker, No.openRight).array;
    assert(second == [[1], [2, 3]]);
}

Instead, `second` is [[1], [2, 3], [4]].

This happens because `until` does not differentiate "range is T[] and sentinel is T[]" from "range is _T[][]_ and sentinel is T[]". This leads it to advance two rather than one elements if the sentinel is two long.

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