Created attachment 329674 [details]
ensure tgid is always set

Description of problem:
When htop is configured to show a tree view

Version-Release number of selected component (if applicable):
htop-0.8.1-2.fc10
This is a regression -- 0.7.x didn't have this problem.

How reproducible:
Very easy to reproduce

Steps to Reproduce:
1. Edit or create ~/.htoprc, and set hide_userland_threads=1 and tree_view=1.
2. Start htop
3. Note that it is not actually displaying a tree view.
  
Actual results:
Processes are shown without threads in a flat view.  Pressing F5 to toggle tree view will change the order, but it remains flat.  Pressing H twice to toggle user threads on and off again will restore the proper tree hierarchy (until htop is restarted).

Expected results:
Processes are shown without threads in a tree view to begin with.

Additional info:
The problem is that when htop is hiding user threads, it doesn't go through the enumeration that sets the tgid in its process structures.  Every process is left with tgid=0, which prevents the tree generator from working.

The attached patch fixes the problem by setting tgid=pid when the parent pointer is NULL.

I've posted this to the upstream mailing list and bug tracker as well, but haven't gotten any response.
http://sourceforge.net/tracker/?func=detail&atid=651633&aid=2022810&group_id=108839

Ubuntu accepted this patch for jaunty from LP #298232.