Careful profiling shows that we spend more time guessing what pattern
allocation will have, whereas we can delay it only at the point where
add_rfc2047 will be used and don't allocate huge memory area for the many
cases where it's not.
Signed-off-by: Pierre Habouzit <madcoder@debian.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>