diff --git a/stdlib/LinearAlgebra/src/triangular.jl b/stdlib/LinearAlgebra/src/triangular.jl index bc6c2a64a6d7d..5c3f728eeaa5e 100644 --- a/stdlib/LinearAlgebra/src/triangular.jl +++ b/stdlib/LinearAlgebra/src/triangular.jl @@ -1296,6 +1296,7 @@ function generic_trimatdiv!(C::AbstractVecOrMat, uploc, isunitc, tfun::Function, if size(C) != size(B) throw(DimensionMismatch(lazy"size of output, $(size(C)), does not match size of right hand side, $(size(B))")) end + iszero(mA) && return C oA = oneunit(eltype(A)) @inbounds if uploc == 'U' if isunitc == 'N' @@ -1432,6 +1433,7 @@ function generic_trimatdiv!(C::AbstractVecOrMat, uploc, isunitc, ::Function, xA: if size(C) != size(B) throw(DimensionMismatch(lazy"size of output, $(size(C)), does not match size of right hand side, $(size(B))")) end + iszero(mA) && return C oA = oneunit(eltype(A)) @inbounds if uploc == 'U' if isunitc == 'N' diff --git a/stdlib/LinearAlgebra/test/lu.jl b/stdlib/LinearAlgebra/test/lu.jl index a4cbdbe3eb9b9..0cb45047a118c 100644 --- a/stdlib/LinearAlgebra/test/lu.jl +++ b/stdlib/LinearAlgebra/test/lu.jl @@ -486,4 +486,17 @@ end LinearAlgebra.generic_lufact!(fill(Inf, 2, 2), check=false) end +@testset "lu for empty matrices" begin + for T in (Float64, BigFloat) + A = fill(T(0.0), 0, 0) + v = fill(T(1.0), 0, 10) + @test A \ v ≈ lu(A) \ v + vt = permutedims(v) + @test vt / A ≈ vt / lu(A) + B = UpperTriangular(transpose(fill(complex(T(0.0)), 0, 0)')) + @test B \ v ≈ v + @test vt / B ≈ vt + end +end + end # module TestLU