Fix bug in length of BlockedUnitRange with non-1 start (#167)

Author: dlfivefifty

Project.toml

@@ -1,6 +1,6 @@
 name = "BlockArrays"
 uuid = "8e7c35d0-a365-5155-bbbb-fb81a777f24e"
-version = "0.15.1"
+version = "0.15.2"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"

src/blockaxis.jl

@@ -62,7 +62,7 @@ _diff(a::AbstractVector) = diff(a)
 _diff(a::Tuple) = diff(collect(a))
 @inline blocklengths(a::BlockedUnitRange) = [first(a.lasts)-a.first+1; _diff(a.lasts)]
 
-length(a::BlockedUnitRange) = isempty(a.lasts) ? 0 : Integer(last(a.lasts))
+length(a::BlockedUnitRange) = isempty(a.lasts) ? 0 : Integer(last(a.lasts)-a.first+1)
 
 """
    blockisequal(a::AbstractUnitRange{Int}, b::AbstractUnitRange{Int})

test/test_blockindices.jl

@@ -224,17 +224,23 @@ end
     end
 
     @testset "BlockIndex indexing" begin
-       b = blockedrange([1,2,3])
-       @test b[Block(3)[2]] == b[Block(3)][2] == 5
-       @test b[Block(3)[2:3]] == b[Block(3)][2:3] == 5:6
+        b = blockedrange([1,2,3])
+        @test b[Block(3)[2]] == b[Block(3)][2] == 5
+        @test b[Block(3)[2:3]] == b[Block(3)][2:3] == 5:6
     end
 
     @testset "BlockRange indexing" begin
-       b = blockedrange([1,2,3])
-       @test b[Block.(1:2)] == blockedrange([1,2])
-       @test b[Block.(1:3)] == b
-       @test_throws BlockBoundsError b[Block.(0:2)]
-       @test_throws BlockBoundsError b[Block.(1:4)]
+        b = blockedrange([1,2,3])
+        @test b[Block.(1:2)] == blockedrange([1,2])
+        @test b[Block.(1:3)] == b
+        @test_throws BlockBoundsError b[Block.(0:2)]
+        @test_throws BlockBoundsError b[Block.(1:4)]
+ 
+        @testset "bug" begin
+            b = blockedrange(1:4)
+            @test b[Block.(2:4)] == 2:10
+            @test length(b[Block.(2:4)]) == 9
+        end
     end
 
     @testset "misc" begin