LHelp shows empty window (if F1 context sensitive help called twice)

Original Reporter info from Mantis: yurix

• Reporter name: Yuri

Description:

If LHep window is not closed, then next context sensitive help shows window without navigation (and not shows properly help).

Steps to reproduce:

For example:

1. Put cursor on "TForm" class and press F1.
   
2. Do not close LHelp window. Switch window back to Lazarus.
   
3. Put cursor on "TThread" class (or on any else keyword) and press F1.
   LHelp show glitch window.

Mantis conversion info:

• Mantis ID: 29747
• OS: Windows
• OS Build: XP, 7, 8.1
• Build: 51630
• Platform: x86, x64
• Version: 1.6
• Fixed in version: 2.2
• Fixed in revision: 64159 (#de6bb064)
• Monitored by: » seniorandre (Andrey Sobol)
• Target version: 2.2