I upgrade to the latest release Freeglut (I had a lot of
customizations and fixes I didn't want to port yet). Anyway, I
noticed flicker when resizing the window.
I tracked it down to this new code: line 834 of freeglut_main.c:
if ( window != fgStructure.CurrentWindow )
By commenting out this line the flicker disappeared.
It is strange since I would expected having this check, which keeps
the code from redundantly resetting the device context, would have the
opposite effect of reducing flicker.
There might be some intervening code that makes certain assumptions
about how this check should work invalid.