Editing: lists getting misnumbered

Version: 70.0b1 (64-bit)

Adding sublists within lists gets the outer list misnumbered:

Step 1 - make ordered list 1 to 4
  1. Item 1

  2. Item 2

  3. Item 3

  4. Item 4
    Step 2 - go to Item 2, add new “item 2a”:

  5. Item 1

  6. Item 2

  7. Item 2a

  8. Item 3

  9. Item 4
    Step 3 - Press to indent Item 2a, to make it a sub list:

  10. Item 1

  11. Item 2

  12. Item 2a

  13. Item 3

  14. Item 4
    Note: “Item 3” is now numbered as 2, instead of 3 as expected.

    Step 4 - Add new sub item “Item 2b”

  15. Item 1

  16. Item 2

  17. Item 2a

  18. Item 2b

  19. Item 3

  20. Item 4
    Step 5 - Add another sub item “Item 2c”

  21. Item 1

  22. Item 2

  23. Item 2a

  24. Item 2b

  25. Item 2c

  26. Item 3

  27. Item 4
    Note: “Item 3” gets shifted to 4!

    This is a regression, the list editing used to work fine in Beta
    69.0 and earlier.

    Regards

    -T.W.Chan-