bugfix reading arrays (#234)

* bugfix reading arrays

* add tests

Co-authored-by: Jon Alm Eriksen <jon.alm.eriksen@novelda.com>

src/FlatBuffers/table.jl

@@ -103,7 +103,7 @@ end
 function Array{T}(t::Table, off) where {T}
     a = vector(t, off)
     S = T <: Table ? UOffsetT : T <: Struct ? NTuple{structsizeof(T), UInt8} : T
-    ptr = convert(Ptr{S}, pointer(bytes(t), pos(t) + a + 1))
+    ptr = convert(Ptr{S}, pointer(bytes(t), a + 1))
     data = unsafe_wrap(Base.Array, ptr, vectorlen(t, off))
     return Array{T, S, typeof(t)}(t, a, data)
 end

test/runtests.jl

@@ -409,6 +409,35 @@ tbl = Arrow.Table(Arrow.tobuffer(cols))
 @test tbl.k1 == cols.k1
 @test tbl.k2 == cols.k2
 
+# PR 234
+# bugfix parsing primitive arrays
+buf = [
+    0x14,0x00,0x00,0x00,0x00,0x00,0x0e,0x00,0x14,0x00,0x00,0x00,0x10,0x00,0x0c,0x00,0x08,
+    0x00,0x04,0x00,0x0e,0x00,0x00,0x00,0x2c,0x00,0x00,0x00,0x38,0x00,0x00,0x00,0x38,0x00,
+    0x00,0x00,0x38,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+    0x03,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x02,0x00,0x00,0x00,0x03,0x00,0x00,0x00,0x00,
+    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+]
+
+struct TestData <: Arrow.FlatBuffers.Table
+    bytes::Vector{UInt8}
+    pos::Base.Int
+end
+
+function Base.getproperty(x::TestData, field::Symbol)
+    if field === :DataInt32
+        o = Arrow.FlatBuffers.offset(x, 12)
+        o != 0 && return Arrow.FlatBuffers.Array{Int32}(x, o)
+    else
+        @warn "field $field not supported"
+    end
+end
+
+d = Arrow.FlatBuffers.getrootas(TestData, buf, 0);
+@test d.DataInt32 == UInt32[1,2,3]
+
+
 end # @testset "misc"
 
 end