formatter: factor out function that detects node change and document it This prepares for demand loading of ctx/fctx objects. With this change, 'revcache' is also recreated if 'node' value changes, which will be needed to support loading of ctx from (repo, node) pair.

formatter: inline _gettermap and _knownkeys

formatter: fill missing resources by formatter, not by resource mapper While working on demand loading of ctx/fctx objects, I found it's weird to support lookup in both directions. For instance, fctx can be loaded from (ctx, path) pair, but ctx may also be derived from fctx.changectx() in the original mapping. If the original mapping has had fctx but no ctx, and if the new mapping provides {path}, we can't be sure if fctx should be updated by fctx'.changectx()[path] or not. This patch simply drops the support for the resolution in fctx -> ctx -> repo direction.

templater: remove unused context argument from most resourcemapper functions While working on demand loading of ctx/fctx objects, I noticed that it's quite easy to create infinite recursion by carelessly using the template context in the resource mapper. Let's make that not happen.

ancestor: remove extra generator from lazyancestors.__iter__()

localrepo: fix a mixmatched arg name in createrepository() docstring Differential Revision: https://phab.mercurial-scm.org/D4548

error: ensure ProgrammingError message is always a str Since this error is internal-only and a runtime error, let's give it a treatment that makes it behave identically when repr()d on both Python 2 and Python 3. Differential Revision: https://phab.mercurial-scm.org/D4545