[BUG] `primary:=false` series messes with legend entries

[baggepinnen]

Details

Here's a MWE. The series in the middle, primary := false, messes with the order of the legend entries in the plots coming after it

struct Foo end

@recipe function fooplot(f::Foo)
    layout --> 2
    subplot := 1
    @series begin
        linecolor -> [1 2]
        label := ["1" "2"]
        randn(3, 2)
    end

    @series begin
        linecolor --> 1
        primary --> false
        [1]
    end

    subplot := 2
    @series begin
        linecolor := [1 2]
        label := ["1" "2"]
        randn(3, 2)
    end
end
plot(Foo())

look at the legend in the second subplot

Backends

Both GR and plotly

Versions

Plots.jl version: Plots v1.25.10 Backend version (]st -m <backend(s)>): GR v0.64.0 Output of versioninfo():

julia> versioninfo()
Julia Version 1.7.1
Commit ac5cc99908 (2021-12-22 19:35 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: AMD Ryzen 9 5900X 12-Core Processor
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.1 (ORCJIT, znver3)
Environment:
  JULIA_NUM_THREADS = 12
  JULIA_EDITOR = code
  JULIA_SSH_NO_VERIFY_HOSTS = gitlab.cognibotics.net
  JULIA_PKG_PRECOMPILE_AUTO = 1
  JULIA_NUM_PRECOMPILE_TASKS = 6

[BeastyBlacksmith]

I think this has the same cause as https://discourse.julialang.org/t/odd-behaviour-of-custom-labels-in-plot-recipes/76057/12, namely bad interaction of the argument cycling with recipes.

For now I'd advise to construct only a single series per @series block.