fix plotattributes in _add_plot_title!

src/args.jl

@@ -2059,7 +2059,7 @@ function _update_subplot_args(
 )
     anns = RecipesPipeline.pop_kw!(sp.attr, :annotations)
 
-    # # grab those args which apply to this subplot
+    # grab those args which apply to this subplot
     for k in keys(_subplot_defaults)
         slice_arg!(plotattributes_in, sp.attr, k, subplot_index, remove_pair)
     end

src/pipeline.jl

@@ -266,7 +266,7 @@ function _subplot_setup(plt::Plot, plotattributes::AKW, kw_list::Vector{KW})
         sp_attrs[sp] = attr
     end
 
-    _add_plot_title!(plt)
+    _add_plot_title!(plt, plotattributes)
     # override subplot/axis args.  `sp_attrs` take precendence
     for (idx, sp) in enumerate(plt.subplots)
         attr = if !haskey(plotattributes, :subplot) || plotattributes[:subplot] == idx
@@ -287,7 +287,7 @@ function series_idx(kw_list::AVec{KW}, kw::AKW)
     Int(kw[:series_plotindex]) - Int(kw_list[1][:series_plotindex]) + 1
 end
 
-function _add_plot_title!(plt)
+function _add_plot_title!(plt, plotattributes)
     plot_title = plt[:plot_title]
 
     if plot_title != ""
@@ -308,6 +308,9 @@ function _add_plot_title!(plt)
             plt[:plot_titleindex] = subplot[:subplot_index]
             subplot[:framestyle] = :none
             subplot[:margin] = 0px
+            # prevents propagation (see JuliaPlots/Plots.jl/issues/4083)
+            pop!(plotattributes, :framestyle, nothing)
+            pop!(plotattributes, :margin, nothing)
             push!(plt.subplots, subplot)
         end
 

src/plot.jl

@@ -163,7 +163,7 @@ function plot!(plt1::Plot, plt2::Plot, plts_tail::Plot...; kw...)
             cmdidx += 1
         end
     end
-    _add_plot_title!(plt)
+    _add_plot_title!(plt, plotattributes)
 
     # first apply any args for the subplots
     for (idx, sp) in enumerate(plt.subplots)

test/test_layouts.jl

@@ -25,3 +25,8 @@ end
     @test pl[:plot_title] == "My new title"
     @test pl[:plot_titleindex] == 5
 end
+
+@testset "Plots.jl/issues/4083" begin
+    p = plot(plot(1:2), plot(1:2); border = :grid, plot_title = "abc")
+    @test p.subplots[end][:framestyle] === :none
+end