XLSX: a customFormat row style on trailing empty cells does not widen the print range, so a formatted empty column and its header fill are dropped

[developer0hye]

Summary

Excel extends a sheet's printed range to columns that carry formatting even when they hold
no cell value: a row-level customFormat style whose fill spans a trailing empty column
makes that column part of every printed page. office2pdf derives the printed range from
populated cells only, so a formatted-but-empty trailing column and its fill band are
dropped from the output entirely.

Measured

NumberFormatTests.xlsx Tests sheet, row 1 (customFormat style s=3, orange fill): GT
prints an empty 64pt column E on every one of the sheet's 8 pages, with the A1:E1 header
fill band spanning 461pt. office2pdf prints columns A–D only; the fill band measures 396pt.

	GT (Excel)	office2pdf
printed columns	A–E	A–D
header fill band width	461pt	396pt
empty formatted column E	64pt, present	absent

Reproduction

cargo run -p office2pdf-cli -- tests/fixtures/xlsx/poi/NumberFormatTests.xlsx -o out.pdf
mutool draw -F trace -o - out.pdf 2 | grep fill_path   # header band 396pt; GT 461pt incl. column E

Expected

The printed range includes formatted-but-empty trailing columns, as Excel prints them.

Actual

Only populated columns print: the formatted empty column and its header fill vanish.

Related: #621

Found in: the #621 fix-PR visual audit (NumberFormatTests.xlsx Tests sheet p1, local Excel-for-Mac GT, 150 DPI, 2026-07-30). Visual comparison below.

Visual comparison

Compare

GT left (Letter), office2pdf right (A4), 150 DPI, Tests sheet page 1.