Description of Problem:
When I upgraded from initscripts 5.49 to 6.40 an old problem reappeared. 
For PPP interfaces using demand dialing, "ifup" hangs.

In the 5.49 version of ifup-ppp the DEMAND option modified the behaviour of
the script in some critical places.  This code apparently was lost
somewhere on the way to 6.40.  As far as I can understand it is still
needed.  At least for me, "ifup" hangs when I try to do "ifup ppp0".  And
consequently, the boot process don't run smoothly.
 
I modified ifup-ppp with some code from the 5.49, and my system appears to
be fine again.  I enclose the patch. (Beware, though, this is not very well
tested.)

Version-Release number of selected component (if applicable):
6.40-1

How Reproducible:
Always.

Steps to Reproduce:
1.  Set DEMAND=yes in one ifcfg-pppX
2.  Do "ifup pppX" for the same X.

Actual Results:
The ifup don't finish.

Expected Results:
I expect ifup to finish.  Apparently the boot scripts do too.