bookmarks: refer to "the" active bookmark to clarify that there's only one
This is a follow-on to
0c6cdbb697d9 that just makes a slight clarification.
memctx: allow extensions to determine what filectxfn should do
Rev
650b5b6e75ed switched the contract for filectxfn from "raise IOError if
file is missing" to "return None if file is missing". Out of tree extensions
need to be updated for that, but for extensions interested in compatibility
with both Mercurial <= 3.1 and default, it is next to impossible to introspect
core Mercurial to figure out what to do.
This patch adds a field to memctx for extensions to use.
revsetbenchmark: add revset with lazyset subtraction
The added revset is used by obsolescence and currently results in
recursion in __contains__ between 2 lazysets. We should have
coverage of this revset.