fix(frames): Inherit class direction setting in new frames

classes/plain.lua

@@ -34,7 +34,14 @@ plain.defaultFrameset = {
 plain.firstContentFrame = "content"
 
 plain.options.direction = function (value)
-  if value then plain.defaultFrameset.content.direction = value end
+  SILE.documentState.direction = value
+  if value then
+    for _, frame in pairs(plain.defaultFrameset) do
+      if not frame.direction then
+        frame.direction = value
+      end
+    end
+  end
 end
 
 function plain:init ()

core/frame.lua

@@ -19,6 +19,10 @@ SILE.framePrototype = pl.class({
 
     -- This gets called by Penlght when creating the frame instance
     _init = function (self, spec, dummy)
+      local direction = SILE.documentState.direction
+      if direction then
+        self.direction = direction
+      end
       self.constraints = {}
       self.variables = {}
       self.id = spec.id