Inverse broken for adjoint matrices

[fremling]

I have noticed that the adjoint (') functionality breaks the matrix inversion (inv) unless one get's rid of the adjoint attribute (by e.g. multiplying by one).

Here is a minimal working example

function InverseOfAdjoint()
    TheMatrix = fill(im*0.0,2,2)
    TheMatrix[1,2]=im
    TheMatrix[2,1]=im

    println("TheMatrix:")
    display(TheMatrix)

    TheAdjoint=TheMatrix'
    println("TheAdjoint:")
    display(TheAdjoint)

    InverseMatrix=inv(TheMatrix)
    println("InverseMatrix:")
    display(InverseMatrix)

    InverseNumericAdjoint=inv(TheAdjoint .* 1.0)
    println("InverseNumericAdjoint:")
    display(InverseNumericAdjoint)

    InverseAdjoint=inv(TheAdjoint)
    println("InverseAdjoint:")
    display(InverseAdjoint)
end

InverseOfAdjoint()

Which cause the output:

TheMatrix:
2×2 Array{Complex{Float64},2}:
 0.0+0.0im  0.0+1.0im
 0.0+1.0im  0.0+0.0im
TheAdjoint:
2×2 Adjoint{Complex{Float64},Array{Complex{Float64},2}}:
 0.0-0.0im  0.0-1.0im
 0.0-1.0im  0.0-0.0im
InverseMatrix:
2×2 Array{Complex{Float64},2}:
 -0.0+0.0im  0.0-1.0im
  0.0-1.0im  0.0+0.0im
InverseNumericAdjoint:
2×2 Array{Complex{Float64},2}:
 0.0-0.0im  0.0+1.0im
 0.0+1.0im  0.0+0.0im
ERROR: LoadError: MethodError: no method matching adjoint(::LDLt{Complex{Float64},SymTridiagonal{Complex{Float64},Array{Complex{Float64},1}}})
Closest candidates are:
  adjoint(::Missing) at missing.jl:79
  adjoint(::Number) at number.jl:193
  adjoint(::Adjoint) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.0/LinearAlgebra/src/adjtrans.jl:104
  ...
Stacktrace:
 [1] factorize(::Adjoint{Complex{Float64},Array{Complex{Float64},2}}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.0/LinearAlgebra/src/dense.jl:1216
 [2] inv(::Adjoint{Complex{Float64},Array{Complex{Float64},2}}) at /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.0/LinearAlgebra/src/generic.jl:803
 [3] InverseOfAdjoint() at MinimalExample.jl:22
 [4] top-level scope at none:0
 [5] include at ./boot.jl:317 [inlined]
 [6] include_relative(::Module, ::String) at ./loading.jl:1044
 [7] include(::Module, ::String) at ./sysimg.jl:29
 [8] include(::String) at ./client.jl:392
 [9] top-level scope at none:0
in expression starting at MinimalExample.jl:27

[pablosanjose]

This seems to be fixed on v1.1 and later, although it does fail on v1.0

[StefanKarpinski]

Yes, see #26302 and #30047. This is a feature, so not eligible for backport to the 1.0.x series.