Improve Error Messages in the Confusing DivideError when plotting empty data with GR backend

[singularitti]

I encountered an issue when running a plot with empty y-data using the following code:

using Plots

plot([1], [])

This results in the following stack trace:

Error showing value of type Plots.Plot{Plots.GRBackend}:
ERROR: DivideError: integer division error
Stacktrace:
  [1] div
    @ ./int.jl:295 [inlined]
  [2] div
    @ ./div.jl:310 [inlined]
  [3] div
    @ ./div.jl:355 [inlined]
  [4] fld
    @ ./div.jl:321 [inlined]
  [5] mod
    @ ./int.jl:287 [inlined]
  [6] mod1
    @ ./operators.jl:839 [inlined]
  [7] mod
    @ ./range.jl:1495 [inlined]
  [8] _cycle(v::Vector{Float64}, idx::Int64)
    @ Plots ~/.julia/packages/Plots/kLeqV/src/utils.jl:196
  [9] _guess_best_legend_position(xl::Tuple{…}, yl::Tuple{…}, plt::Plots.Subplot{…}, weight::Int64)
    @ Plots ~/.julia/packages/Plots/kLeqV/src/utils.jl:1216
 [10] _guess_best_legend_position(xl::Tuple{…}, yl::Tuple{…}, plt::Plots.Subplot{…})
    @ Plots ~/.julia/packages/Plots/kLeqV/src/utils.jl:1200
 [11] _guess_best_legend_position(lp::Symbol, plt::Plots.Subplot{Plots.GRBackend})
    @ Plots ~/.julia/packages/Plots/kLeqV/src/utils.jl:1240
 [12] gr_legend_pos(sp::Plots.Subplot{…}, leg::@NamedTuple{…}, vp::Plots.GRViewport{…})
    @ Plots ~/.julia/packages/Plots/kLeqV/src/backends/gr.jl:1145
 [13] gr_add_legend(sp::Plots.Subplot{…}, leg::@NamedTuple{…}, viewport_area::Plots.GRViewport{…})
    @ Plots ~/.julia/packages/Plots/kLeqV/src/backends/gr.jl:1008
 [14] gr_display(sp::Plots.Subplot{…}, w::Measures.AbsoluteLength, h::Measures.AbsoluteLength, vp_canvas::Plots.GRViewport{…})
    @ Plots ~/.julia/packages/Plots/kLeqV/src/backends/gr.jl:972
 [15] (::Plots.var"#508#509"{Int64, Int64, Plots.GRViewport{Float64}})(sp::Plots.Subplot{Plots.GRBackend})
    @ Plots ~/.julia/packages/Plots/kLeqV/src/backends/gr.jl:688
 [16] foreach(f::Plots.var"#508#509"{Int64, Int64, Plots.GRViewport{Float64}}, itr::Vector{Plots.Subplot})
    @ Base ./abstractarray.jl:3187
 [17] gr_display(plt::Plots.Plot{Plots.GRBackend}, dpi_factor::Int64)
    @ Plots ~/.julia/packages/Plots/kLeqV/src/backends/gr.jl:688
 [18] gr_display
    @ ~/.julia/packages/Plots/kLeqV/src/backends/gr.jl:658 [inlined]
 [19] #564
    @ ~/.julia/packages/Plots/kLeqV/src/backends/gr.jl:2114 [inlined]
 [20] withenv(::Plots.var"#564#566"{Plots.Plot{Plots.GRBackend}}, ::Pair{String, String}, ::Vararg{Pair{String}})
    @ Base ./env.jl:265
 [21] _display(plt::Plots.Plot{Plots.GRBackend})
    @ Plots ~/.julia/packages/Plots/kLeqV/src/backends/gr.jl:2113
 [22] display(::Plots.PlotsDisplay, plt::Plots.Plot{Plots.GRBackend})
    @ Plots ~/.julia/packages/Plots/kLeqV/src/output.jl:169

The error message is not very clear and might confuse users, especially in longer or more complex code.

Would it be possible to improve the error handling here, perhaps with a more informative message, or catch the case where one or more inputs are empty?

System Information:

julia> versioninfo()
Julia Version 1.11.0
Commit 501a4f25c2b (2024-10-07 11:40 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: macOS (arm64-apple-darwin22.4.0)
  CPU: 16 × Apple M3 Max
  WORD_SIZE: 64
  LLVM: libLLVM-16.0.6 (ORCJIT, apple-m3)
Threads: 12 default, 0 interactive, 6 GC (on 12 virtual cores)

Possibly related issues: #1329, #448