logm issue

[andreasnoack]

As reported by @iamnapo in #414

julia> B = [3 2; -5 -3]
2×2 Array{Int64,2}:
  3   2
 -5  -3

julia> expm(logm(B))
2×2 Array{Float64,2}:
 -5.33599  -5.66504
 17.5616   18.4572

[YingboMa]

Also, Julia will hang in this situation.

julia> B = [1 -1; 1 -1]
2×2 Array{Int64,2}:
 1  -1
 1  -1

julia> logm(B)

The while loop in this line will never terminate.

https://github.com/JuliaLang/julia/blob/master/base/linalg/triangular.jl#L1698

[iamnapo]

I'd like to work on this if anyone else isn't already. Are there any relevant commits/PRs I could look for help?

[andreasnoack]

I know that @YingboMa looked a bit at this function yesterday. @YingboMa, are you already working on this?

[YingboMa]

Yes, I plan to work on this.