Fix integer_partitions(0)

Author: inkydragon

src/partitions.jl

@@ -456,7 +456,7 @@ function integer_partitions(n::Integer)
     if n < 0
         throw(DomainError(n, "n must be nonnegative"))
     elseif n == 0
-        return Vector{Int}[]
+        return Vector{Int}[[]]
     elseif n == 1
         return Vector{Int}[[1]]
     end

test/partitions.jl

@@ -27,8 +27,10 @@
     @test length(collect(partitions('a':'h', 5))) == length(partitions('a':'h', 5))
 
     # integer_partitions
-    @test integer_partitions(0) == []
-    @test integer_partitions(5) == Any[[1, 1, 1, 1, 1], [2, 1, 1, 1], [2, 2, 1], [3, 1, 1], [3, 2], [4, 1], [5]]
+    @test integer_partitions(0) == [Int[]]
+    @test integer_partitions(1) == [[1]]
+    # gap> Partitions( 5 );
+    @test integer_partitions(5) == [[1, 1, 1, 1, 1], [2, 1, 1, 1], [2, 2, 1], [3, 1, 1], [3, 2], [4, 1], [5]]
     @test_throws DomainError integer_partitions(-1)
 
     @test_throws ArgumentError prevprod([2, 3, 5], Int128(typemax(Int)) + 1)