New UnexpectedOutput exception to catch server errors in localrepo.stream_in If the unexpected is a string, the empty string will be mentioned, and long strings are cut to at most 400 chars.

#!/bin/sh

hg init
python -c 'print "confuse str.splitlines\nembedded\rnewline"' > a
hg ci -Ama -d '1 0'
echo clean diff >> a
hg ci -mb -d '2 0'
hg diff -r0 -r1