Inference error with Array{Union{Int,Missing}} after resize

[shashi]

When I resize the array, julia errors trying to print it.

julia> x=Array{Union{Int, Missing}}(undef, 1)
1-element Array{Union{Missing, Int64},1}:
 missing

julia> resize!(x, 100)
100-element Array{Union{Missing, Int64},1}:
Error showing value of type Array{Union{Missing, Int64},1}:
ERROR: fatal error in type inference (type bound)
Stacktrace:
 [1] alignment(::IOContext{REPL.Terminals.TTYTerminal}, ::Array{Union{Missing, Int64},1}, ::Array{Int64,1}, ::Base.OneTo{Int64}, ::Int64, ::Int64, ::Int64) at ./arrayshow.jl:68
 [2] print_matrix(::IOContext{REPL.Terminals.TTYTerminal}, ::Array{Union{Missing, Int64},1}, ::String, ::String, ::String, ::String, ::String, ::String, ::Int64, ::Int64) at ./arrayshow.jl:186
 [3] print_matrix at ./arrayshow.jl:159 [inlined]
 [4] print_array at ./arrayshow.jl:308 [inlined]
 [5] show(::IOContext{REPL.Terminals.TTYTerminal}, ::MIME{Symbol("text/plain")}, ::Array{Union{Missing, Int64},1}) at ./arrayshow.jl:344
 [6] display(::REPL.REPLDisplay{REPL.LineEditREPL}, ::MIME{Symbol("text/plain")}, ::Array{Union{Missing, Int64},1}) at /home/shashi/code/julia/stdlib/REPL/src/REPL.jl:130
 [7] display(::REPL.REPLDisplay{REPL.LineEditREPL}, ::Array{Union{Missing, Int64},1}) at /home/shashi/code/julia/stdlib/REPL/src/REPL.jl:133
 [8] display(::Array{Union{Missing, Int64},1}) at ./multimedia.jl:287
 [9] #invokelatest#1 at ./essentials.jl:670 [inlined]
 [10] invokelatest at ./essentials.jl:669 [inlined]
 [11] print_response(::REPL.Terminals.TTYTerminal, ::Any, ::Nothing, ::Bool, ::Bool, ::Nothing) at /home/shashi/code/julia/stdlib/REPL/src/REPL.jl:151
 [12] print_response(::REPL.LineEditREPL, ::Any, ::Nothing, ::Bool, ::Bool) at /home/shashi/code/julia/stdlib/REPL/src/REPL.jl:137
 [13] (::getfield(REPL, Symbol("#do_respond#42")){Bool,getfield(REPL, Symbol("##52#61")){REPL.LineEditREPL,REPL.REPLHistoryProvider},REPL.LineEditREPL,REPL.LineEdit.Prompt})(::REPL.LineEdit.MIState, ::Base.GenericIOBuffer{Array{UInt8,1}}, ::Bool) at /home/shashi/code/julia/stdlib/REPL/src/REPL.jl:706
 [14] top-level scope at none:0

Now if I try to do typeof on each element:

julia> map(typeof, x)
Unreachable reached at 0x7f943056711b

signal (4): Illegal instruction
in expression starting at no file:0
getindex at ./array.jl:707 [inlined]
iterate at ./array.jl:682 [inlined]
iterate at ./generator.jl:44 [inlined]
collect_to! at ./array.jl:630 [inlined]
collect_to_with_first! at ./array.jl:617
unknown function (ip: 0x7f9430567163)
jl_fptr_trampoline at /home/shashi/code/julia/src/gf.c:1813
jl_apply_generic at /home/shashi/code/julia/src/gf.c:2151
_collect at ./array.jl:611
collect_similar at ./array.jl:535
jl_fptr_trampoline at /home/shashi/code/julia/src/gf.c:1813
jl_apply_generic at /home/shashi/code/julia/src/gf.c:2151
map at ./abstractarray.jl:1964
jl_fptr_trampoline at /home/shashi/code/julia/src/gf.c:1813
jl_apply_generic at /home/shashi/code/julia/src/gf.c:2151
do_call at /home/shashi/code/julia/src/interpreter.c:324
eval_value at /home/shashi/code/julia/src/interpreter.c:428
eval_stmt_value at /home/shashi/code/julia/src/interpreter.c:363 [inlined]
eval_body at /home/shashi/code/julia/src/interpreter.c:671
jl_interpret_toplevel_thunk_callback at /home/shashi/code/julia/src/interpreter.c:788
unknown function (ip: 0xfffffffffffffffe)
unknown function (ip: 0x7f943341d20f)
unknown function (ip: 0xffffffffffffffff)
jl_interpret_toplevel_thunk at /home/shashi/code/julia/src/interpreter.c:797
jl_toplevel_eval_flex at /home/shashi/code/julia/src/toplevel.c:814
jl_toplevel_eval_in at /home/shashi/code/julia/src/builtins.c:631
eval at ./boot.jl:319
jl_apply_generic at /home/shashi/code/julia/src/gf.c:2151
eval_user_input at /home/shashi/code/julia/usr/share/julia/stdlib/v0.7/REPL/src/REPL.jl:85
macro expansion at /home/shashi/code/julia/usr/share/julia/stdlib/v0.7/REPL/src/REPL.jl:116 [inlined]
#28 at ./task.jl:257
jl_fptr_trampoline at /home/shashi/code/julia/src/gf.c:1813
jl_apply_generic at /home/shashi/code/julia/src/gf.c:2151
jl_apply at /home/shashi/code/julia/src/julia.h:1533 [inlined]
start_task at /home/shashi/code/julia/src/task.c:268
unknown function (ip: 0xffffffffffffffff)
Allocations: 4864217 (Pool: 4863286; Big: 931); GC: 9
Illegal instruction (core dumped)

Could be another issue or a clue to the first one.

[martinholters]

Seems to be a problem with the new values being uninitialized. Doing e.g. fill!(resize!(x, 100), missing), everything seems to work smoothly. I guess we should not leave the values that uninitialized.

[quinnj]

Yeah, any resizing of isbitsunion Arrays should do a memset on the new type tag bytes to 0.