Sometimes the repr of an object can contain the "\n{" sequence which is
used as a formatting language, so they are escaped to "\\n{". But the
collapse-false code needs to look for the real "\n{" token instead of
simply "{" as otherwise it may get unbalanced braces from the object's
repr (sometimes caused by the collapsing of long reprs by saferepr).
Fixes issue #731.
--HG--
branch : pytest-2.7