basectx: add an empty class that will be used as a parent of all contexts
At the moment, there is no simple way to check if an object is a context
because there is no common parent class. If there were, we could use
'isinstance' everywhere. Simply having memctx inherit from workingctx or
changectx would allow the use of 'isinstance' but that could lead to some
confusing situations of reading the code since we have three distinct concepts
of a context:
- changectx represents a changeset *already* in the repo, and is therefore immutable
- workingctx represents changes on disk in the working directory
- memctx represents changes solely in memory which may or may not be on disk
Therefore, I propose refactoring context.py to have all three contexts inherit
from a parent class 'basectx'.
Create an empty repo:
$ hg init a
$ cd a
Try some commands:
$ hg log
$ hg grep wah
[1]
$ hg manifest
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
0 files, 0 changesets, 0 total revisions
Check the basic files created:
$ ls .hg
00changelog.i
requires
store
Should be empty:
$ ls .hg/store
Poke at a clone:
$ cd ..
$ hg clone a b
updating to branch default
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd b
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
0 files, 0 changesets, 0 total revisions
$ ls .hg
00changelog.i
branch
dirstate
hgrc
requires
store
Should be empty:
$ ls .hg/store
$ cd ..