Fix error in validating complex row-first hvncat (#45365)

base/abstractarray.jl

@@ -2396,14 +2396,17 @@ function _typed_hvncat_dims(::Type{T}, dims::NTuple{N, Int}, row_first::Bool, as
  # validate shapes for lowest level of concatenation
  d = findfirst(>(1), dims)
  if d !== nothing # all dims are 1
+ if row_first && d < 3
+ d = d == 1 ? 2 : 1
+ end
  nblocks = length(as) ÷ dims[d]
  for b ∈ 1:nblocks
  offset = ((b - 1) * dims[d])
  startelementi = offset + 1
  for i ∈ offset .+ (2:dims[d])
  for dd ∈ 1:N
  dd == d && continue
- if size(as[startelementi], dd) != size(as[i], dd)
+ if cat_size(as[startelementi], dd) != cat_size(as[i], dd)
  throw(ArgumentError("incompatible shape in element $i"))
  end
  end

test/abstractarray.jl

@@ -1543,6 +1543,8 @@ using Base: typed_hvncat
  # Issue 43933 - semicolon precedence mistake should produce an error
  @test_throws ArgumentError [[1 1]; 2 ;; 3 ; [3 4]]
  @test_throws ArgumentError [[1 ;;; 1]; 2 ;;; 3 ; [3 ;;; 4]]
+
+ @test [[1 2; 3 4] [5; 6]; [7 8] 9;;;] == [1 2 5; 3 4 6; 7 8 9;;;]
 end
 
 @testset "keepat!" begin