context: add deprecation warnings for deprecated types of changeids It's close to code freeze, and dropping support for repo['123'] and repo ['my-bookmark'] and repo['deadbeef'] is pretty dispruptive, so this just adds deprecation warnings so extensions can easily find the places they need to fix. Differential Revision: https://phab.mercurial-scm.org/D3197

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

context: handle partial nodeids in revsymbol() Similar reasoning as previous patches. Differential Revision: https://phab.mercurial-scm.org/D3195