This is an update to #1150. I've merged these changes with master as well and tested this on Linux and Windows XP 64 bit and it works fine. The tearing bug isn't completely gone but until we find a cleaner solution this at least makes the pager functional when used in the vsplit mode.
@prabhuramachandran, please simply rebase your branch onto master, so that we don't have criss-crossing of the history. Basically your PR should only show your own commits, and not the master merge. Let us know if you need a hand with the rebase details and we'll be happy to help.
BUG: Scrolling pager in vsplit on Mac OSX tears.
On Mac OS X, scrolling the pager when it is split vertically causes the
help text to tear (i.e. the help text is unreadable). This hack
attempts to make it a little better although the solution may not be
optimal at all.
@fperez, sorry about that, I've rebased and hope this is OK. Do let me know if I've messed anything up. Thanks.
I've also tested on ubuntu 11.10 and it works OK here. Since we had already tested the exact same logic yesterday on OSX, I'll go ahead and merge now. Thanks!