Fix ranges of CartesianIndexes

Author: jishnub

base/multidimensional.jl

@@ -68,6 +68,7 @@ module IteratorsMD
 
     CartesianIndex(index::NTuple{N,Integer}) where {N} = CartesianIndex{N}(index)
     CartesianIndex(index::Integer...) = CartesianIndex(index)
+    CartesianIndex{N}(c::CartesianIndex{N}) where {N} = c
     CartesianIndex{N}(index::Vararg{Integer,N}) where {N} = CartesianIndex{N}(index)
     # Allow passing tuples smaller than N
     CartesianIndex{N}(index::Tuple) where {N} = CartesianIndex{N}(fill_to_length(index, 1, Val(N)))

base/range.jl

@@ -170,13 +170,13 @@ range_stop(stop::Integer) = range_length(stop)
 # Stop and length as the only argument
 range_stop_length(a::Real,          len::Integer) = UnitRange{typeof(a)}(oftype(a, a-len+1), a)
 range_stop_length(a::AbstractFloat, len::Integer) = range_step_stop_length(oftype(a, 1), a, len)
-range_stop_length(a,                len::Integer) = range_step_stop_length(oftype(a-a, 1), a, len)
+range_stop_length(a,                len::Integer) = range_step_stop_length(oftype(a-a, oneunit(a)), a, len)
 
 range_step_stop_length(step, stop, length) = reverse(range_start_step_length(stop, -step, length))
 
 range_start_length(a::Real,          len::Integer) = UnitRange{typeof(a)}(a, oftype(a, a+len-1))
 range_start_length(a::AbstractFloat, len::Integer) = range_start_step_length(a, oftype(a, 1), len)
-range_start_length(a,                len::Integer) = range_start_step_length(a, oftype(a-a, 1), len)
+range_start_length(a,                len::Integer) = range_start_step_length(a, oftype(a-a, oneunit(a)), len)
 
 range_start_stop(start, stop) = start:stop
 

test/ranges.jl

@@ -2112,3 +2112,13 @@ end
 @test length(range(1, 100, length=big(100)^100)) == big(100)^100
 @test length(range(big(1), big(100)^100, length=big(100)^100)) == big(100)^100
 @test length(0 * (1:big(100)^100)) == big(100)^100
+
+@testset "ranges of CartesianIndexes" begin
+    a = CartesianIndex(1,1)
+    r1 = range(a, step = CartesianIndex(2,3), length = 3)
+    r2 = StepRangeLen(CartesianIndex(1,1), CartesianIndex(2,3), 3)
+    @test r1 == r2
+
+    @test range(a, length = 4) == StepRangeLen(a, a, 4)
+    @test range(stop = a, length = 4) == StepRangeLen(-2a, a, 4)
+end