hledger-lib-0.24's "track the commodity of zero amounts when
possible (useful eg for hledger-web's multi-commodity charts)" preserved
the commodity when normalising a zero mixed amount, but not the amount
style. This showed up as occasionally incorrect amount style (commodity
symbol placement, decimal point character, etc.) in balance reports with
certain journals, like this:
$ hledger bal
€3000.00 a <------ not using the canonical € style
4000,58€ 1
-1000,58€ D
-3000,00€ e
--------------------
0
I thought this would require a big rewrite of amount arithmetic, but it
seems that just being a little more careful is enough. When normalising
a mixed amount containing multiple zeros in the same commodity, we now
preserve the last zero with its amount style, instead of replacing them
all with a new one.
b8d75b7728