TouchMenu: Abort early if tap/hold handlers are called on an unpainted

widget

May happen if we have blocking stuff on startup (e.g., Wi-Fi), and you
spam tap the screen during the white screen.

frontend/ui/widget/touchmenu.lua

@@ -157,6 +157,9 @@ function TouchMenuItem:onTapSelect(arg, ges)
     end
     if enabled == false then return end
 
+    -- If the menu hasn't actually been drawn yet, don't do anything (as it's confusing, and the coordinates may be wrong).
+    if not self.item_frame.dimen then return end
+
     if G_reader_settings:isFalse("flash_ui") then
         self.menu:onMenuSelect(self.item)
     else
@@ -200,6 +203,8 @@ function TouchMenuItem:onHoldSelect(arg, ges)
     end
     if enabled == false then return end
 
+    if not self.item_frame.dimen then return end
+
     if G_reader_settings:isFalse("flash_ui") then
         self.menu:onMenuHold(self.item, self.text_truncated)
     else