It's just wasted memory.
One corner case is when a file grows during playback, but this is rare
and usually happens on-disk only. The cache size was generally limited
before this change already, so no reason to care.
As an unrelated change, move the cache size info to the resize_cache()
function. There's really no reason not to do this, and it's slightly
more informative if the user changes the cache size at runtime.
wm4
b636b19058