tuple splatting bug with simple program

[BrianGun]

version information:

Julia Version 1.0.3
Commit 099e826241 (2018-12-18 01:34 UTC)
Platform Info:
  OS: Windows (x86_64-w64-mingw32)
  CPU: Intel(R) Xeon(R) CPU E5-2680 v4 @ 2.40GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-6.0.0 (ORCJIT, broadwell)
Environment:
  JULIA_EDITOR = "C:\JuliaPro-1.0.3.1\app-1.32.2\atom.exe" -a
  JULIA_NUM_THREADS = 16
  JULIA_PKG_SERVER = https://pkg.juliacomputing.com/
  JULIA_PKG_TOKEN_PATH = C:\Users\bguenter\.juliapro\token.toml

Smallest function that produces the bug

julia> function test(input...)
       b::NTuple = input
       end
test (generic function with 1 method)

How to produce the bug

julia> test(1,2,3)

Unreachable reached at 000000001DBCAA98

Please submit a bug report with steps to reproduce this fault, and any error messages that follow (i
n their entirety). Thanks.
Exception: EXCEPTION_ILLEGAL_INSTRUCTION at 0x1dbcaa98 -- test at .\none:2
in expression starting at no file:0
test at .\none:2
jl_fptr_trampoline at /home/Administrator/buildbot/worker/package_win64/build/src\gf.c:1831
jl_apply_generic at /home/Administrator/buildbot/worker/package_win64/build/src\gf.c:2184do_call at /home/Administrator/buildbot/worker/package_win64/build/src\interpreter.c:324
eval_value at /home/Administrator/buildbot/worker/package_win64/build/src\interpreter.c:430
eval_stmt_value at /home/Administrator/buildbot/worker/package_win64/build/src\interpreter.c:363 [in
lined]
eval_body at /home/Administrator/buildbot/worker/package_win64/build/src\interpreter.c:678
jl_interpret_toplevel_thunk_callback at /home/Administrator/buildbot/worker/package_win64/build/src\
interpreter.c:806
unknown function (ip: FFFFFFFFFFFFFFFE)
unknown function (ip: 00000000119D37FF)
unknown function (ip: FFFFFFFFFFFFFFFF)
jl_toplevel_eval_flex at /home/Administrator/buildbot/worker/package_win64/build/src\toplevel.c:805
jl_toplevel_eval_in at /home/Administrator/buildbot/worker/package_win64/build/src\builtins.c:622
eval at .\boot.jl:319 [inlined]
repleval at C:\Users\bguenter\.juliapro\JuliaPro_v1.0.3.1\packages\Atom\v2iqN\src\repl.jl:139
jl_apply_generic at /home/Administrator/buildbot/worker/package_win64/build/src\gf.c:2184#164 at C:\Users\bguenter\.juliapro\JuliaPro_v1.0.3.1\packages\Atom\v2iqN\src\repl.jl:161with_logstate at .\logging.jl:395
with_logger at .\logging.jl:491 [inlined]
evalrepl at C:\Users\bguenter\.juliapro\JuliaPro_v1.0.3.1\packages\Atom\v2iqN\src\repl.jl:152
jl_apply_generic at /home/Administrator/buildbot/worker/package_win64/build/src\gf.c:2184do_call at /home/Administrator/buildbot/worker/package_win64/build/src\interpreter.c:324
eval_value at /home/Administrator/buildbot/worker/package_win64/build/src\interpreter.c:430
eval_stmt_value at /home/Administrator/buildbot/worker/package_win64/build/src\interpreter.c:363 [in
lined]
eval_body at /home/Administrator/buildbot/worker/package_win64/build/src\interpreter.c:678
jl_interpret_toplevel_thunk_callback at /home/Administrator/buildbot/worker/package_win64/build/src\
interpreter.c:806
unknown function (ip: FFFFFFFFFFFFFFFE)
unknown function (ip: 00000000119D348F)
unknown function (ip: FFFFFFFFFFFFFFFF)
jl_toplevel_eval_flex at /home/Administrator/buildbot/worker/package_win64/build/src\toplevel.c:805
jl_toplevel_eval_in at /home/Administrator/buildbot/worker/package_win64/build/src\builtins.c:622
eval at .\boot.jl:319
jl_apply_generic at /home/Administrator/buildbot/worker/package_win64/build/src\gf.c:2184eval_user_input at C:\Users\julia\AppData\Local\Julia-1.0.3\share\julia\stdlib\v1.0\REPL\src\REPL.jl
:85
macro expansion at C:\Users\julia\AppData\Local\Julia-1.0.3\share\julia\stdlib\v1.0\REPL\src\REPL.jl
:117 [inlined]
#28 at .\task.jl:259
jl_fptr_trampoline at /home/Administrator/buildbot/worker/package_win64/build/src\gf.c:1831
jl_apply_generic at /home/Administrator/buildbot/worker/package_win64/build/src\gf.c:2184jl_apply at /home/Administrator/buildbot/worker/package_win64/build/src\julia.h:1537 [inlined]
start_task at /home/Administrator/buildbot/worker/package_win64/build/src\task.c:268
Allocations: 30636752 (Pool: 30631301; Big: 5451); GC: 69

Julia has exited. Press Enter to start a new session.

[ararslan]

I can reproduce on Linux with Julia 1.0, 1.1, and current master. It works as expected on 0.6 and 0.7.

[JeffBezanson]

Looks like the behavior change is due to changing the tuple convert methods, but all versions have this root cause:

T = Tuple{Type{NTuple}, Tuple}

julia> typeintersect(T, Tuple{Type{Tuple{Vararg{V}}}, Tuple} where V)
Tuple{Type{Tuple{Vararg{T,N}} where T where N},Tuple}

julia> typeintersect(T, Tuple{Type{Tuple{Vararg{V}}}, Tuple{Vararg{V}}} where V)
Union{}

They should probably both be Union{} (in which case we might have to add a method), but making the second one non-empty would fix this too.

[JeffBezanson]

Looks related to the first example here: #24166 (comment)
also this comment in the code:

# TODO: These currently can't be used since
#   Type{NTuple} <: (Type{Tuple{Vararg{S}}} where S) is true
#   even though the value S doesn't exist