updated for version 7.3.1151 Problem: New regexp engine: Slow when a look-behind match is followed by a zero-width match. Solution: Postpone the look-behind match more often.

start of test file Xxx
vim: set noai :
	this is a test
	this is a test
	this is a test
	this is a test
this is some more text
end of test file Xxx
this is another test line