title: Frame disappears with grid_propagate
body: <p>I was recently encountering this problem... I created some frames, and when i'm using <code>grid_propagate(False)</code> on them before I run it, the frames are empty on the window. If I run it with idle without the propagate function, there are there, even when I call the <code>grid_propagate</code> method afterwards.</p>
  
  <pre><code>import tkinter as tk
  
  root = tk.Tk()
  frame = tk.Frame(root)
  text = tk.Text(frame, bg='#000000', fg='#00cc00')
  
  
  frame.grid(row=0, column=0)
  text.grid(row=0, column=0)
  frame.grid_propagate(0)
  </code></pre>
  
  <p>I put the specific commands behind a comment char. It only works for me, when I enter them separately in the Idle after running it.</p>