Matching of floating-point zeroes will change in OTP-27 so that -0.0 will
no longer match a non-negative 0.0. OTP-26.1 warns about such constructs,
which in decimal results in:

===> Compiling decimal
src/decimal_conv.erl:101:12: Warning: matching on the float 0.0 will no longer also match -0.0 in OTP 27. If you specifically intend to match 0.0 alone, write +0.0 instead.

Fixed by switching from a match to a numerical comparison.