[gobo-eiffel-develop] Formatting service does not display plus sign

[Colin A. <col...@go...>]

I inherited from ST_FORMATTING_SERVICES, and called:

format ("$+G", <<ds-cell-of-double>>)

The result was formatted fine except no + sign appeared (it was a
positive number).

This looks like a bug to me - I did some debugging, and the + flag was
recognised and the boolean set accordingly.