py3: add couple of missing b'' prefixes in tests/test-pager-legacy.t # skip-blame because just b'' prefixes Differential Revision: https://phab.mercurial-scm.org/D3784

import: use context manager for lock, dirstateguard, transaction A tiny side-effect is that the transaction is now closed after saving the commit message. Differential Revision: https://phab.mercurial-scm.org/D3748

streamclone: update progress later to avoid passing None to util.bytecount Differential Revision: https://phab.mercurial-scm.org/D3773

highlight: adjust to attribute being private Differential Revision: https://phab.mercurial-scm.org/D3772

annotate: automatically populate fields referenced from template If '{line_number}' is in the template, we'll probably need it. No --line-number option should be required in such cases.

annotate: reverse mapping between option name and field name This makes the next patch slightly simpler.

formatter: provide hint of referenced field names I don't like the function name, but I call it datahint() for consistency with another function I'll add later, fm.contexthint().

templater: add function to look up symbols used in template Formatter can use this information to enable slow paths such as loading ctx object only when necessary.

templater: parse template string to tree by templater class The parsed tree could be cached, but it isn't for now. We can add a cache later if that matters.

templater: drop extension point of engine classes (API) I don't think this would ever be used by third-party extensions, as we've heavily changed both the templater internals and the syntax since then. The main reason of removing this API is that I want to move the parsing function from the engine to the templater class so that we can peek keywords and functions used in a user template. This change also removes reference cycle between the templater and the engine.