Merge pull request #138 from JuliaArrays/noinfiter

Don't iterate infinitely on empty ranges

Author: chriselrod

src/ranges.jl

@@ -399,7 +399,11 @@ end
 const OptionallyStaticRange = Union{<:OptionallyStaticUnitRange,<:OptionallyStaticStepRange}
 
 Base.eachindex(r::OptionallyStaticRange) = r
-@inline Base.iterate(r::OptionallyStaticRange) = (fi = Int(first(r)); (fi, fi))
+@inline function Base.iterate(r::OptionallyStaticRange)
+    isempty(r) && return nothing
+    fi = Int(first(r));
+    fi, fi
+end
 
 Base.to_shape(x::OptionallyStaticRange) = length(x)
 Base.to_shape(x::Slice{T}) where {T<:OptionallyStaticRange} = length(x)