From 04119473f154c37400446d28486527bddd41b6cd Mon Sep 17 00:00:00 2001
From: jishnub <jishnub@users.noreply.github.com>
Date: Thu, 25 Feb 2021 11:01:25 +0400
Subject: [PATCH] Preserve ranges in indexing with IIUR(::OneTo)

---
 src/OffsetArrays.jl |  8 ++++----
 src/utils.jl        |  2 +-
 test/runtests.jl    | 25 ++++++++++++++++++++++---
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/src/OffsetArrays.jl b/src/OffsetArrays.jl
index f02bd30a..d6e06fca 100644
--- a/src/OffsetArrays.jl
+++ b/src/OffsetArrays.jl
@@ -349,19 +349,19 @@ end
 
 for OR in [:IIUR, :IdOffsetRange]
     for R in [:StepRange, :StepRangeLen, :LinRange, :UnitRange]
-        @eval @propagate_inbounds Base.getindex(r::$R, s::$OR) = OffsetArray(r[no_offset_view(s)], axes(s))
+        @eval @propagate_inbounds Base.getindex(r::$R, s::$OR) = _maybewrapaxes(r[UnitRange(s)], axes(s,1))
     end
 
     # this method is needed for ambiguity resolution
     @eval @propagate_inbounds Base.getindex(r::StepRangeLen{T,<:Base.TwicePrecision,<:Base.TwicePrecision}, s::$OR) where T =
-    OffsetArray(r[no_offset_view(s)], axes(s))
+    _maybewrapaxes(r[UnitRange(s)], axes(s,1))
     
     #= Integer UnitRanges may return an appropriate AbstractUnitRange{<:Integer}, as the result may be used in indexing, and
     indexing is faster with ranges =#
     @eval @propagate_inbounds function Base.getindex(r::UnitRange{<:Integer}, s::$OR)
-        rs = r[no_offset_view(s)]
+        rs = r[UnitRange(s)]
         offset_s = first(axes(s,1)) - 1
-        IdOffsetRange(UnitRange(rs .- offset_s), offset_s)
+        _maybewrapoffset(UnitRange(rs .- offset_s), offset_s, axes(s,1))
     end
 end
 
diff --git a/src/utils.jl b/src/utils.jl
index ba52fce7..585a3838 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -75,7 +75,7 @@ end
 _maybewrapaxes(A::AbstractVector, ::Base.OneTo) = no_offset_view(A)
 _maybewrapaxes(A::AbstractVector, ax) = OffsetArray(A, ax)
 
-_maybewrapoffset(r::AbstractUnitRange, of, ::Base.OneTo) = no_offset_view(r)
+_maybewrapoffset(r::AbstractUnitRange, of, ::Base.OneTo) = UnitRange(r)
 _maybewrapoffset(r::AbstractVector, of, ::Base.OneTo) = no_offset_view(r)
 _maybewrapoffset(r::AbstractUnitRange, of, ::Any) = IdOffsetRange(UnitRange(r), of)
 _maybewrapoffset(r::AbstractVector, of, axs) = OffsetArray(r .+ of, axs)
diff --git a/test/runtests.jl b/test/runtests.jl
index 68cb5db8..898ce1ce 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -852,15 +852,34 @@ end
 
         # AbstractRanges with 1-based indices
         for r2 in [
-            5:80, 
-            5:2:80, 
-            IdOffsetRange(5:80), 
+            5:80,
+            5:2:80,
+            IdOffsetRange(5:80),
             IdOffsetRange(ZeroBasedUnitRange(4:79), 1),
             ]
 
             test_indexing_axes_and_vals(r1, r2)
         end
     end
+
+    # Indexing with IdentityUnitRange(::Base.OneTo) is special as this has 1-based
+    # indices and the indexing operation leads to the correct axes in Base.
+    # The result should not be changed in this package.
+    # Also Issue 209 for versions v"1,0.x"
+    for r1 in [
+        UnitRange(1.0, 99.0),
+        1:99,
+        1:1:99,
+        1.0:1.0:99.0,
+        StepRangeLen(Float64(1), Float64(99), 99),
+        LinRange(1, 99, 99),
+        ]
+
+        for r2 in [IdentityUnitRange(Base.OneTo(10))]
+            test_indexing_axes_and_vals(r1, r2)
+            @test r1[r2] isa AbstractRange
+        end
+    end
 end
 
 @testset "Vector indexing with offset ranges" begin