revsymbol: stop delegating to repo.__getitem__ for unhandled symbols (API) The only remaining cases where we were delegating unhandled symbols to repo.__getitem__ should now be when the symbol could not be found. In that case we just delegated to repo.__getitem__ for the error message. Let's just copy the error message instead. If there were any cases where we got e.g. a binary nodeid or an integer revnum into revsymbol() (e.g. via repo.lookup()), we'd now start raising an exception instead. That is why this is marked (API). This affects one test case, but the new behavior seems better to me. I can't tell if the old behavior was desired or if the test was just there to document how it happened to work. Differential Revision: https://phab.mercurial-scm.org/D3196