[REPL] Autocompletion of `using` multiple submodules is broken

[giordano]

Julia v1.10.2, in a REPL session:

using Base.Threads, Base.Thre<TAB>

results in

julia> using Base.Threads, Base.Thre┌ Error: Error in the keymap
│   exception =
│    UndefVarError: `out` not defined
│    Stacktrace:
│      [1] complete_identifiers!(suggestions::Vector{REPL.REPLCompletions.Completion}, ffunc::Any, context_module::Module, string::String, name::String, pos::Int64, dotpos::Int64, startpos::Int64; comp_keywords::Bool)
│        @ REPL.REPLCompletions ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/REPLCompletions.jl:1055
│      [2] complete_identifiers!
│        @ ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/REPLCompletions.jl:983 [inlined]
│      [3] completions(string::String, pos::Int64, context_module::Module, shift::Bool)
│        @ REPL.REPLCompletions ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/REPLCompletions.jl:1299
│      [4] complete_line(c::REPL.REPLCompletionProvider, s::REPL.LineEdit.PromptState, mod::Module)
│        @ REPL ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/REPL.jl:545
│      [5] complete_line(s::REPL.LineEdit.PromptState, repeats::Int64, mod::Module)
│        @ REPL.LineEdit ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/LineEdit.jl:376
│      [6] complete_line(s::REPL.LineEdit.MIState)
│        @ REPL.LineEdit ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/LineEdit.jl:367
│      [7] edit_tab(s::REPL.LineEdit.MIState, jump_spaces::Bool, delete_trailing::Bool)
│        @ REPL.LineEdit ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/LineEdit.jl:2320
│      [8] edit_tab
│        @ ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/LineEdit.jl:2320 [inlined]
│      [9] (::REPL.LineEdit.var"#114#170")(::REPL.LineEdit.MIState, ::Any, ::Vararg{Any})
│        @ REPL.LineEdit ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/LineEdit.jl:2366
│     [10] #invokelatest#2
│        @ ./essentials.jl:892 [inlined]
│     [11] invokelatest
│        @ ./essentials.jl:889 [inlined]
│     [12] (::REPL.LineEdit.var"#27#28"{REPL.LineEdit.var"#114#170", String})(s::Any, p::Any)
│        @ REPL.LineEdit ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/LineEdit.jl:1612
│     [13] prompt!(term::REPL.Terminals.TextTerminal, prompt::REPL.LineEdit.ModalInterface, s::REPL.LineEdit.MIState)
│        @ REPL.LineEdit ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/LineEdit.jl:2749
│     [14] run_interface(terminal::REPL.Terminals.TextTerminal, m::REPL.LineEdit.ModalInterface, s::REPL.LineEdit.MIState)
│        @ REPL.LineEdit ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/LineEdit.jl:2651
│     [15] run_frontend(repl::REPL.LineEditREPL, backend::REPL.REPLBackendRef)
│        @ REPL ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/REPL.jl:1312
│     [16] (::REPL.var"#62#68"{REPL.LineEditREPL, REPL.REPLBackendRef})()
│        @ REPL ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/REPL.jl:386
└ @ REPL.LineEdit ~/.julia/juliaup/julia-1.10.2+0.x64.linux.gnu/share/julia/stdlib/v1.10/REPL/src/LineEdit.jl:2751
julia> 
julia> 

In Julia master this doesn't crash, but it also doesn't complete the second Base.Thre. This works as expected in Julia v1.9.

[aviatesk]

Fixed by #53273 and will be included in v1.10.3.

[giordano]

In Julia master this doesn't crash, but it also doesn't complete the second Base.Thre.