bug#44799: 28.0.50; Calc: Meter not printed as \text in latex output

[Mattias Engdegård]

It seems to be a heuristic for distinguishing units from variables, both of 
which unfortunately have the same representation in Calc. We could make it more 
precise by looking in the unit table (and allow for prefixes), but it would 
mean that a variable 'm' would always look like a unit. I'm afraid I have no 
other good solution at hand.

For that matter, shouldn't units use \mathrm{} rather than \text{} ?