Fix HermitianLayout

Author: dlfivefifty

Project.toml

@@ -15,7 +15,7 @@ Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 [compat]
 ArrayLayouts = "0.8.2"
 BandedMatrices = "0.16.8, 0.17"
-BlockArrays = "0.16.6"
+BlockArrays = "0.16.14"
 FillArrays = "0.13"
 MatrixFactorizations = "0.8.5, 0.9"
 julia = "1.6"

src/AbstractBlockBandedMatrix.jl

@@ -40,7 +40,7 @@ conjlayout(::Type{T}, ::BlockBandedColumns{Lay}) where {T<:Complex,Lay} = BlockB
 conjlayout(::Type{T}, ::BlockBandedRows{Lay}) where {T<:Complex,Lay} = BlockBandedRows{typeof(conjlayout(T,Lay))}()
 
 symmetriclayout(::AbstractBandedBlockBandedLayout) = BandedBlockBandedLayout()
-hermitianlayout(::AbstractBandedBlockBandedLayout) = BandedBlockBandedLayout()
+hermitianlayout(_, ::AbstractBandedBlockBandedLayout) = BandedBlockBandedLayout()
 
 function blockbandwidths(S::HermOrSym)
     l, u = blockbandwidths(parent(S))

test/test_bandedblockbanded.jl

@@ -524,11 +524,19 @@ import ArrayLayouts: RangeCumsum
         cols = rows = 1:N
         data = reshape(collect(1:(λ+μ+1)*(l+u+1)*sum(cols)), ((λ + μ + 1) * (l + u + 1), sum(cols)))
         A = _BandedBlockBandedMatrix(data, rows, cols, (l, u), (λ, μ))
+        
+        @test blockbandwidths(Hermitian(A)) == blockbandwidths(Symmetric(A)) == (1,1)
+        @test blockbandwidths(Hermitian(A,:L)) == blockbandwidths(Symmetric(A,:L)) == (2,2)
+        @test subblockbandwidths(Hermitian(A)) == subblockbandwidths(Symmetric(A)) == (2,2)
+        @test subblockbandwidths(Hermitian(A,:L)) == subblockbandwidths(Symmetric(A,:L)) == (2,2)
 
         @test BandedBlockBandedMatrix(Symmetric(A)) == Symmetric(Matrix(A))
         @test BandedBlockBandedMatrix(Symmetric(A,:L)) == Symmetric(Matrix(A),:L)
         @test BandedBlockBandedMatrix(Hermitian(A)) == Hermitian(Matrix(A))
         @test BandedBlockBandedMatrix(Hermitian(A,:L)) == Hermitian(Matrix(A),:L)
+
+        @test Symmetric(A)[Block.(1:3),Block.(1:3)] isa BandedBlockBandedMatrix
+        @test Hermitian(A)[Block.(1:3),Block.(1:3)] isa BandedBlockBandedMatrix
     end
 end