Non-rectangular head-spanning articles

[robertjlee]

The "headspan" article type works well for rectangular articles that don't split across pages. But there is an edge case that isn't well catered for: if you have a split-able (currently "paste-up") article, there is a good chance that the top edge of each column will line up on at least the first few columns.

In this case, it makes sense to set the headline spanning across the columns where the top edge is aligned, especially if this represents all columns across which the article is set. This means the article will take up more space, and we will need to recalculate the article length, but this will look better on the page, especially with longer headlines.

There could be three options:

1. Paste-up only; headline at top of first column
2. Span on the first columns where the top-edge matches, allowing offset columns
3. Span only if all columns line up and are set on the same page (essentially allowing a headspan article with each column potentially a different length).

NB: This may confuse the initial estimate of column and page count, especially option 2.