Wrong conversion from dimensionless Quantity to Gain

[sostock]

using convert:

julia> convert(typeof(1.0u"dB_rp"), 100.0) # correct
40.0 dB

julia> convert(typeof(1.0u"dB_rp"), 1.0u"m/cm") # this should be the same, because 1m/cm == 100
100.0 dB

using uconvert:

julia> uconvert(u"dB_rp", 100.0) # correct
40.0 dB

julia> uconvert(u"dB_rp", 1.0u"m/cm") # a _different_ wrong result
0.0 dB

[sostock]

The other direction works correctly for both convert and uconvert:

julia> convert(Float64, 40.0u"dB_rp")
100.0

julia> convert(typeof(1.0u"m/cm"), 40.0u"dB_rp")
1.0 m cm^-1

julia> uconvert(NoUnits, 40.0u"dB_rp")
100.0

julia> uconvert(u"m/cm", 40.0u"dB_rp")
1.0 m cm^-1

[sostock]

Mixed units are interesting as well:

julia> convert(typeof(1.0u"dB_p/s"), 1.0u"dB_p/s")
[1.0 dB] s^-1

julia> convert(typeof(1.0u"dB_p/s"), 1u"dB_p/s")
[1.2589254117941673 dB] s^-1