Broadcasting regression with adjoints in 0.16.22

m = mortar([rand(i,j) for i=1:3, j=2:3])
m .- (1:5)'

In 0.16.22-23:

ERROR: BoundsError: attempt to access 1-element Vector{Int64} at index [2]
Stacktrace:
  [1] getindex
    @ .\array.jl:861 [inlined]
  [2] iterate
    @ C:\Users\sternlab\.julia\packages\BlockArrays\0XNk5\src\blockbroadcast.jl:128 [inlined]
  [3] _zip_iterate_some
    @ .\iterators.jl:358 [inlined]
  [4] _zip_iterate_some (repeats 2 times)
    @ .\iterators.jl:360 [inlined]
  [5] _zip_iterate_all
    @ .\iterators.jl:350 [inlined]
  [6] iterate
    @ .\iterators.jl:341 [inlined]
  [7] macro expansion
    @ C:\Users\sternlab\.julia\packages\BlockArrays\0XNk5\src\blockbroadcast.jl:172 [inlined]
  [8] _generic_blockbroadcast_copyto!(dest::BlockMatrix{Float64, Matrix{Matrix{Float64}}, Tuple{BlockedUnitRange{Vector{Int64}}, BlockedUnitRange{Vector{Int64}}}}, bc::Base.Broadcast.Broadcasted{BlockArrays.BlockStyle{2}, Tuple{BlockedUnitRange{Vector{Int64}}, BlockedUnitRange{Vector{Int64}}}, typeof(-), Tuple{BlockMatrix{Float64, Matrix{Matrix{Float64}}, Tuple{BlockedUnitRange{Vector{Int64}}, BlockedUnitRange{Vector{Int64}}}}, LinearAlgebra.Adjoint{Int64, UnitRange{Int64}}}})
    @ BlockArrays C:\Users\sternlab\.julia\packages\BlockArrays\0XNk5\src\blockbroadcast.jl:148
  [9] copyto!(dest::BlockMatrix{Float64, Matrix{Matrix{Float64}}, Tuple{BlockedUnitRange{Vector{Int64}}, BlockedUnitRange{Vector{Int64}}}}, bc::Base.Broadcast.Broadcasted{BlockArrays.BlockStyle{2}, Tuple{BlockedUnitRange{Vector{Int64}}, BlockedUnitRange{Vector{Int64}}}, typeof(-), Tuple{BlockMatrix{Float64, Matrix{Matrix{Float64}}, Tuple{BlockedUnitRange{Vector{Int64}}, BlockedUnitRange{Vector{Int64}}}}, LinearAlgebra.Adjoint{Int64, UnitRange{Int64}}}})
    @ BlockArrays C:\Users\sternlab\.julia\packages\BlockArrays\0XNk5\src\blockbroadcast.jl:190
 [10] copy
    @ .\broadcast.jl:885 [inlined]
 [11] materialize(bc::Base.Broadcast.Broadcasted{BlockArrays.BlockStyle{2}, Nothing, typeof(-), Tuple{BlockMatrix{Float64, Matrix{Matrix{Float64}}, Tuple{BlockedUnitRange{Vector{Int64}}, BlockedUnitRange{Vector{Int64}}}}, LinearAlgebra.Adjoint{Int64, UnitRange{Int64}}}})
    @ Base.Broadcast .\broadcast.jl:860
 [12] top-level scope
    @ Untitled-4:8

This works fine in 0.16.21.

Reproduce the broadcasting expression from the issue in Julia 0.16.22-23 and compare it with 0.16.21. Start in src/blockbroadcast.jl around the iterate and _generic_blockbroadcast_copyto! locations shown in the stack trace. Done means the adjoint expression no longer raises the BoundsError and retains the behavior seen in 0.16.21.