Absolute value is broken for ArbComplex

[DanielVandH]

Maybe I'm doing something wrong, but absolute values on ArbComplex returns zero every time:

julia> z = 0.5 + 0.3im;

julia> abs(z)
0.5830951894845301

julia> z = ArbComplex(0.5, 0.3)
0.5 + 0.2999999999999999888977697537484im

julia> abs(z)
0

The issue seems to be with z = ArbReal{P}() in

ArbNumerics.jl/src/float/prearith.jl

Lines 84 to 88 in 0cfcf98

	function abs(x::ArbComplex{P}) where {P}
	z = ArbReal{P}()
	ccall(@libarb(acb_abs), Cvoid, (Ref{ArbComplex}, Ref{ArbComplex}, Clong), z, x, P)
	return z
	end

. If I instead use this method:

function _abs(x::ArbComplex{P}) where {P}
    z = ArbComplex{P}()
    ccall(ArbNumerics.@libarb(acb_abs), Cvoid, (Ref{ArbComplex}, Ref{ArbComplex}, Clong), z, x, P)
    return real(z)
end
_abs(ArbComplex(0.5, 0.3, bits=256))
abs(0.5 + 0.3im)

julia> _abs(ArbComplex(0.5, 0.3, bits=256))
0.58309518948453004137536495027902554867375965029811700288720077783633574140908

julia> abs(0.5 + 0.3im)
0.5830951894845301

Then it seems to work.

[JeffreySarnoff]

thank you for this

[JeffreySarnoff]

fixed in master, merge pending