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

JuliaLang · Apr 11, 2020 · 797f769 · 797f769
1 parent c8d277f
commit 797f769
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Showing 2 changed files with 6 additions and 1 deletion.
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)