non-scalar indexing is broken for ArrayPartition

[kolia]

using RecursiveArrayTools
a = ArrayPartition(1:5, 1:6)

a[1:8]
a[[1,3,8]]

both throw

ERROR: DimensionMismatch("output array is the wrong size; expected (Base.OneTo(8),), got (11,)")
Stacktrace:
 [1] throw_checksize_error(::ArrayPartition{Int64,Tuple{Array{Int64,1},Array{Int64,1}}}, ::Tuple{Base.OneTo{Int64}}) at ./multidimensional.jl:625
 [2] _unsafe_getindex(::IndexCartesian, ::ArrayPartition{Int64,Tuple{UnitRange{Int64},UnitRange{Int64}}}, ::UnitRange{Int64}) at ./multidimensional.jl:602
 [3] _getindex at ./multidimensional.jl:589 [inlined]
 [4] getindex(::ArrayPartition{Int64,Tuple{UnitRange{Int64},UnitRange{Int64}}}, ::UnitRange{Int64}) at ./abstractarray.jl:905

Single-indexing a[3] works just fine, obviously.

[ChrisRackauckas]

Fixed

[jleugeri]

Hi, not sure if this is a regression, but I just ran into the exact same problem in version v2.7.1:

   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.5.2 (2020-09-23)
 _/ |\__'_|_|_|\__'_|  |  Official https://julialang.org/ release
|__/                   |

(@v1.5) pkg> status
Status `C:\Users\XXX\.julia\environments\v1.5\Project.toml`
  ...
  [731186ca] RecursiveArrayTools v2.7.1
  ...

julia> using RecursiveArrayTools

julia> a = ArrayPartition(1:5, 1:6)
(1:5, 1:6)

julia>

julia> a[1:8]
ERROR: DimensionMismatch("output array is the wrong size; expected (Base.OneTo(8),), got (11,)")
Stacktrace:
 [1] throw_checksize_error(::ArrayPartition{Int64,Tuple{Array{Int64,1},Array{Int64,1}}}, ::Tuple{Base.OneTo{Int64}}) at .\multidimensional.jl:779
 [2] _unsafe_getindex(::IndexCartesian, ::ArrayPartition{Int64,Tuple{UnitRange{Int64},UnitRange{Int64}}}, ::UnitRange{Int64}) at .\multidimensional.jl:756
 [3] _getindex at .\multidimensional.jl:743 [inlined]
 [4] getindex(::ArrayPartition{Int64,Tuple{UnitRange{Int64},UnitRange{Int64}}}, ::UnitRange{Int64}) at .\abstractarray.jl:1060
 [5] top-level scope at REPL[3]:1

julia> a[[1,3,8]]
ERROR: DimensionMismatch("output array is the wrong size; expected (Base.OneTo(3),), got (11,)")
Stacktrace:
 [1] throw_checksize_error(::ArrayPartition{Int64,Tuple{Array{Int64,1},Array{Int64,1}}}, ::Tuple{Base.OneTo{Int64}}) at .\multidimensional.jl:779
 [2] _unsafe_getindex(::IndexCartesian, ::ArrayPartition{Int64,Tuple{UnitRange{Int64},UnitRange{Int64}}}, ::Array{Int64,1}) at .\multidimensional.jl:756
 [3] _getindex at .\multidimensional.jl:743 [inlined]
 [4] getindex(::ArrayPartition{Int64,Tuple{UnitRange{Int64},UnitRange{Int64}}}, ::Array{Int64,1}) at .\abstractarray.jl:1060
 [5] top-level scope at REPL[4]:1

julia> a[3]
3

julia> a[[1,2,3,4,5,6,7,8,9,10,11]]
([1, 2, 3, 4, 5], [1, 2, 3, 4, 5, 6])

julia>

[ChrisRackauckas]

This is fixed by #116