[BUG] Breakpoint fails if it's the first encountered statement

[timholy]

With

function f(x, y)
    z = x+y
    a = z*x
    return a
end

Juno.@run f(1, 2) fails to stop if you set the breakpoint on the first line of the body. It works if you set it at the 2nd or later line. It works at the first line of f if you do Juno.@run g() where g() = f(1, 2).

[pfitzseb]

I would argue this is a JuliaInterpreter bug:

julia> JuliaInterpreter.breakpoint(gcd)
8-element Array{BreakpointRef,1}:
 breakpoint(gcd(x::BigInt, y::BigInt) in Base.GMP at gmp.jl:403, line 403)
 breakpoint(gcd(a::T, b::T) where T<:Union{Int128, Int16, Int32, Int64, Int8, UInt128, UInt16, UInt32, UInt64, UInt8} in Base at intfuncs.jl:31, line 31)
 breakpoint(gcd(a::Integer) in Base at intfuncs.jl:75, line 75)
 breakpoint(gcd(a::T, b::T) where T<:Integer in Base at intfuncs.jl:20, line 20)
 breakpoint(gcd(a::Integer, b::Integer) in Base at intfuncs.jl:77, line 77)
 breakpoint(gcd(a::Integer, b::Integer...) in Base at intfuncs.jl:79, line 79)
 breakpoint(gcd(abc::AbstractArray{#s72,N} where N where #s72<:Integer) in Base at intfuncs.jl:85, line 85)
 breakpoint(gcd(x::P, y::P) where P<:Dates.Period in Dates at C:\cygwin\home\Administrator\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.1\Dates\src\periods.jl:75, line 75)

julia> frame = JuliaInterpreter.enter_call_expr(Expr(:call, gcd, 2,3))
Frame for gcd(a::T, b::T) where T<:Union{Int128, Int16, Int32, Int64, Int8, UInt128, UInt16, UInt32, UInt64, UInt8} in Base at intfuncs.jl:31
b  1 31  1 ──       Core.NewvarNode(:(za))
   2 31  │          Core.NewvarNode(:(zb))
   3 31  │          Core.NewvarNode(:(k))
⋮
a = 2
b = 3
T = Int64

julia> ret = JuliaInterpreter.debug_command(frame, :finish)

julia> JuliaInterpreter.get_return(root(frame))
1

JuliaDebug/Debugger.jl#134 is the same issue.

[pfitzseb]

Fixed by JunoLab/Atom.jl@8d3040c.