This speeds up the in-memory version of debugbuilddag that I'm
working on considerably for the case where we want to build just
a 00changelog.i (for discovery tests, for instance).
There are a couple of test changes because node ids in tests
have changed.
The changes to the patch names in test-mq-qdelete.t were required
because they could collide with nodeid abbreviations and newly
actually do (patch "c" collides with id "cafe..." for patch "b").
Previously, when rolling back a transaction, some users could be confused
between the level to which the store is rolled back, and the new parents
of the working directory.
$ hg rollback
rolling back to revision 4 (undo commit)
With this change:
$ hg rollback
repository tip rolled back to tip revision 4 (undo commit)
working directory now based on revision 2 and 1
So now the user can realize that the store has been rolled back to an older
tip, but also that the working directory may not on the tip (here we are
rolling back the merge of the heads 2 and 1)
It tries to convert localstr to unicode before truncating.
Because we cannot assume that the given text is encoded in local encoding,
it falls back to raw string in case of unicode error.
