Clearing validation from cells (or setting a new rule, or pasting a
validation over them) and Clear Rules on selected cells shrink a rule's
areas. When that removes the rule's top-left cell, the relative formulas
were left written for the old cell, so the cells left checked other
cells: clearing A1 off a custom `A1>10` on A1:A9 made A2 check A1.
Rewrite the relative references of validation formulas, and of
conditional format expressions and comparison values, for the new
top-left cell. Absolute references and literal lists stay as they are.
Excel writes the relative formulas of a multi-area rule for the top-left
cell of the whole sqref (lowest row, lowest column), whatever order the
areas are listed in. GridCraft anchored them on the first area listed, so
a validation on `H62:H68 H26:H27 H93:H95` with `MOD($H26,$F26)=0` checked
row 26 - 36 at H26 and refused valid input.
Add `RangeRef::top_left` and use it in validation checks, list sources,
pasting a validation, conditional format lookups and the formulas the
xlsx writer generates for text, blank and error rules.
ljkx
Dylan M. Taylor
aiongg