Diagonal(BlockVector) * BlockDiagonal (and vice versa) fails

[mtfishman]

For example:

julia> using BlockArrays

julia> using BlockArrays: BlockDiagonal

julia> using LinearAlgebra

julia> pkgversion(BlockArrays)
v"1.1.1"

julia> pkgversion(LinearAlgebra)
v"1.11.0"

julia> A = BlockDiagonal([randn(2, 2), randn(2, 2)])
2×2-blocked 4×4 BlockMatrix{Float64, Diagonal{Matrix{Float64}, Vector{Matrix{Float64}}}, Tuple{BlockedOneTo{Int64, Vector{Int64}}, BlockedOneTo{Int64, Vector{Int64}}}}:
 -1.73455   1.11785   │    ⋅           ⋅      
 -0.99245  -0.549115  │    ⋅           ⋅      
 ─────────────────────┼───────────────────────
   ⋅         ⋅        │  -0.285518   -0.592538
   ⋅         ⋅        │  -0.0665603   0.425891

julia> D = Diagonal(BlockedVector([1, 2, 3, 4], [2, 2]))
4×4 Diagonal{Int64, BlockedVector{Int64, Vector{Int64}, Tuple{BlockedOneTo{Int64, Vector{Int64}}}}} with indices BlockedOneTo([2, 4])×BlockedOneTo([2, 4]):
 1  ⋅  │  ⋅  ⋅
 ⋅  2  │  ⋅  ⋅
 ──────┼──────
 ⋅  ⋅  │  3  ⋅
 ⋅  ⋅  │  ⋅  4

julia> A * D
ERROR: BoundsError: attempt to access 1-element Base.OneTo{Int64} at index [1:2]
Stacktrace:
  [1] throw_boundserror(A::Base.OneTo{Int64}, I::Tuple{UnitRange{Int64}})
    @ Base ./essentials.jl:14
  [2] checkbounds
    @ ./abstractarray.jl:699 [inlined]
  [3] getindex
    @ ./range.jl:973 [inlined]
  [4] getindex
    @ ~/.julia/packages/BlockArrays/VccC2/src/blockaxis.jl:10 [inlined]
  [5] unblock
    @ ~/.julia/packages/BlockArrays/VccC2/src/views.jl:10 [inlined]
  [6] to_indices
    @ ~/.julia/packages/BlockArrays/VccC2/src/views.jl:29 [inlined]
  [7] to_indices
    @ ~/.julia/packages/BlockArrays/VccC2/src/views.jl:44 [inlined]
  [8] view
    @ ./subarray.jl:213 [inlined]
  [9] _bview
    @ ~/.julia/packages/BlockArrays/VccC2/src/blockbroadcast.jl:124 [inlined]
 [10] (::BlockArrays.var"#56#61"{Base.Broadcast.Broadcasted{…}, Tuple{…}})(i::Int64)
    @ BlockArrays ~/.julia/packages/BlockArrays/VccC2/src/blockbroadcast.jl:156
 [11] ntuple
    @ ./ntuple.jl:19 [inlined]
 [12] _generic_blockbroadcast_copyto!(dest::BlockMatrix{…}, bc::Base.Broadcast.Broadcasted{…})
    @ BlockArrays ~/.julia/packages/BlockArrays/VccC2/src/blockbroadcast.jl:156
 [13] copyto!(dest::BlockMatrix{…}, bc::Base.Broadcast.Broadcasted{…})
    @ BlockArrays ~/.julia/packages/BlockArrays/VccC2/src/blockbroadcast.jl:163
 [14] copy
    @ ./broadcast.jl:892 [inlined]
 [15] materialize
    @ ./broadcast.jl:867 [inlined]
 [16] copy(M::ArrayLayouts.Rmul{BlockArrays.BlockLayout{…}, ArrayLayouts.DiagonalLayout{…}, BlockMatrix{…}, Diagonal{…}})
    @ ArrayLayouts ~/.julia/packages/ArrayLayouts/48qDX/src/diagonal.jl:20
 [17] copy
    @ ~/.julia/packages/ArrayLayouts/48qDX/src/mul.jl:140 [inlined]
 [18] materialize
    @ ~/.julia/packages/ArrayLayouts/48qDX/src/mul.jl:137 [inlined]
 [19] mul
    @ ~/.julia/packages/ArrayLayouts/48qDX/src/mul.jl:138 [inlined]
 [20] *(A::BlockMatrix{Float64, Diagonal{…}, Tuple{…}}, B::Diagonal{Int64, BlockedVector{…}})
    @ ArrayLayouts ~/.julia/packages/ArrayLayouts/48qDX/src/ArrayLayouts.jl:225
 [21] top-level scope
    @ REPL[32]:1
Some type information was truncated. Use `show(err)` to see complete types.

julia> D * A
ERROR: BoundsError: attempt to access 2-blocked 4-element BlockedVector{Int64} at index [BlockSlice(Block(1)[1:2],1:2), BlockSlice(Block(1)[1:2],Base.OneTo(2))]
Stacktrace:
  [1] throw_boundserror(A::BlockedVector{…}, I::Tuple{…})
    @ Base ./essentials.jl:14
  [2] checkbounds
    @ ./abstractarray.jl:699 [inlined]
  [3] view
    @ ./subarray.jl:214 [inlined]
  [4] _bview
    @ ~/.julia/packages/BlockArrays/VccC2/src/blockbroadcast.jl:124 [inlined]
  [5] (::BlockArrays.var"#56#61"{Base.Broadcast.Broadcasted{…}, Tuple{…}})(i::Int64)
    @ BlockArrays ~/.julia/packages/BlockArrays/VccC2/src/blockbroadcast.jl:156
  [6] ntuple
    @ ./ntuple.jl:19 [inlined]
  [7] _generic_blockbroadcast_copyto!(dest::BlockMatrix{…}, bc::Base.Broadcast.Broadcasted{…})
    @ BlockArrays ~/.julia/packages/BlockArrays/VccC2/src/blockbroadcast.jl:156
  [8] copyto!
    @ ~/.julia/packages/BlockArrays/VccC2/src/blockbroadcast.jl:163 [inlined]
  [9] copy
    @ ./broadcast.jl:892 [inlined]
 [10] materialize
    @ ./broadcast.jl:867 [inlined]
 [11] copy
    @ ~/.julia/packages/ArrayLayouts/48qDX/src/diagonal.jl:19 [inlined]
 [12] copy
    @ ~/.julia/packages/ArrayLayouts/48qDX/src/mul.jl:140 [inlined]
 [13] materialize
    @ ~/.julia/packages/ArrayLayouts/48qDX/src/mul.jl:137 [inlined]
 [14] mul
    @ ~/.julia/packages/ArrayLayouts/48qDX/src/mul.jl:138 [inlined]
 [15] *(A::Diagonal{Int64, BlockedVector{…}}, B::BlockMatrix{Float64, Diagonal{…}, Tuple{…}})
    @ ArrayLayouts ~/.julia/packages/ArrayLayouts/48qDX/src/ArrayLayouts.jl:224
 [16] top-level scope
    @ REPL[33]:1
Some type information was truncated. Use `show(err)` to see complete types.

julia> versioninfo()
Julia Version 1.11.1
Commit 8f5b7ca12ad (2024-10-16 10:53 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: macOS (arm64-apple-darwin22.4.0)
  CPU: 10 × Apple M1 Max
  WORD_SIZE: 64
  LLVM: libLLVM-16.0.6 (ORCJIT, apple-m1)
Threads: 1 default, 0 interactive, 1 GC (on 8 virtual cores)

Maybe related to #325. Comes up in #426.