really fix saving

src/backends/gr.jl

@@ -781,13 +781,12 @@ function gr_axis_width(sp, axis)
 end
 
 function _update_min_padding!(sp::Subplot{GRBackend})
+    has_user_gkswstype = haskey(ENV, "GKSwstype")
+    withenv("GKSwstype" => 100, "GKS_ENCODING" => "utf8") do
         dpi = sp.plt[:thickness_scaling]
-    ENV["GKS_ENCODING"] = "utf8"
-    if !haskey(ENV, "GKSwstype")
-        if isijulia()
+        if has_user_gkswstype && isijulia()
             ENV["GKSwstype"] = "svg"
         end
-    end
         # Add margin given by the user
         leftpad   = 2mm  + sp[:left_margin]
         toppad    = 2mm  + sp[:top_margin]
@@ -936,6 +935,7 @@ function _update_min_padding!(sp::Subplot{GRBackend})
             rightpad += 4mm
         end
         sp.minpad = Tuple(dpi * [leftpad, toppad, rightpad, bottompad])
+    end # end withenv
 end
 
 function is_equally_spaced(v)
@@ -1938,20 +1938,17 @@ for (mime, fmt) in (
     "image/svg+xml" => "svg",
 )
     @eval function _show(io::IO, ::MIME{Symbol($mime)}, plt::Plot{GRBackend})
-        ENV["GKS_ENCODING"] = "utf8"
         GR.emergencyclosegks()
         filepath = tempname() * "." * $fmt
-        env = get(ENV, "GKSwstype", "0")
-        ENV["GKSwstype"] = $fmt
-        ENV["GKS_FILEPATH"] = filepath
+        withenv(
+            "GKS_ENCODING" => "utf8", 
+            "GKSwstype" => $fmt, 
+            "GKS_FILEPATH" => filepath
+        ) do
             gr_display(plt, $fmt)
             GR.emergencyclosegks()
             write(io, read(filepath, String))
             rm(filepath)
-        if env != "0"
-            ENV["GKSwstype"] = env
-        else
-            pop!(ENV, "GKSwstype")
         end
     end
 end
@@ -1961,17 +1958,18 @@ function _display(plt::Plot{GRBackend})
     if plt[:display_type] == :inline
         GR.emergencyclosegks()
         filepath = tempname() * ".pdf"
-        ENV["GKSwstype"] = "pdf"
-        ENV["GKS_FILEPATH"] = filepath
+        withenv("GKSwstype" => "pdf", "GKS_FILEPATH" => filepath) do
             gr_display(plt)
             GR.emergencyclosegks()
             content = string("\033]1337;File=inline=1;preserveAspectRatio=0:", base64encode(open(read, filepath)), "\a")
             println(content)
             rm(filepath)
+        end
     else
-        ENV["GKS_DOUBLE_BUF"] = true
+        withenv("GKS_DOUBLE_BUF" => true) do
             gr_display(plt)
         end
     end
+end
 
 closeall(::GRBackend) = GR.emergencyclosegks()