fix JuliaLang#35225, issubset on empty ranges (JuliaLang#35244)

oxinabox · Apr 8, 2020 · 83b6270 · 83b6270
1 parent 774b258
commit 83b6270
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diff --git a/base/range.jl b/base/range.jl
@@ -876,7 +876,7 @@ end
 issubset(r::OneTo, s::OneTo) = r.stop <= s.stop
 
 issubset(r::AbstractUnitRange{<:Integer}, s::AbstractUnitRange{<:Integer}) =
- first(r) >= first(s) && last(r) <= last(s)
+ isempty(r) || first(r) >= first(s) && last(r) <= last(s)
 
 ## linear operations on ranges ##
 

diff --git a/test/ranges.jl b/test/ranges.jl
@@ -387,6 +387,11 @@ end
  @test !issubset(Base.OneTo(10), Base.OneTo(5))
  @test issubset(1:3:10, 1:10)
  @test !issubset(1:10, 1:3:10)
+ # with empty ranges
+ @test issubset(2:1, 3:4) #35225
+ @test issubset(2:1, 3:2)
+ @test issubset(Base.OneTo(0), Base.OneTo(3))
+ @test issubset(Base.OneTo(0), Base.OneTo(-3))
  end
  @testset "sort/sort!/partialsort" begin
  @test sort(UnitRange(1,2)) == UnitRange(1,2)