Function auto_row_height 

pub fn auto_row_height(wb: &mut Workbook, si: usize, row: u32)

Recomputes an automatic row height from its content: the largest font, and wrapped text. Rows with a user-set height keep it.

Line breaks in a cell’s text count only when the cell wraps, as in Excel: with Wrap Text off a multi-line value shows on one line and AutoFit gives a one-line row.