A function gets executes several times while being only called once

[fjarri]

Consider the following code:

function inner(; kw=nothing)
    println("in inner()")
end

function get_inner()
    println("in get_inner()")
    inner
end

function test1()
    f = get_inner()
    f(kw=1)
end

function test2()
    get_inner()(kw=1)
end

function test3()
    get_inner()(; :kw => 1)
end


println("test1:")
test1()
println("test2:")
test2()
println("test3:")
test3()

In each of the test functions I would expect get_inner() to be only called once. Yet the output I get is

test1:
in get_inner()
in inner()
test2:
in get_inner()
in get_inner()
in inner()
test3:
in get_inner()
in get_inner()
in get_inner()
in inner()

Is it some peculiarity of Julia syntax, or a bug?

versioninfo() output:

Julia Version 0.5.1
Commit 6445c82 (2017-03-05 13:25 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin13.4.0)
  CPU: Intel(R) Core(TM) i7-4771 CPU @ 3.50GHz
  WORD_SIZE: 64
  BLAS: libopenblas (USE64BITINT DYNAMIC_ARCH NO_AFFINITY Haswell)
  LAPACK: libopenblas64_
  LIBM: libopenlibm
  LLVM: libLLVM-3.7.1 (ORCJIT, haswell)

[martinholters]

Also present on current master (but for test3, get_inner is only called twice). Seems to be a lowering issue:

julia> expand(:(get_inner()(kw=1)))
:(((Core.kwfunc)(get_inner()))((Base.vector_any)(:kw, 1), get_inner()))

AFAIU, the expression yielding the function to be called would need to be evaluated once with the result being stored in an SSAValue instead of evaluating it twice.