filectx: add isabsent method
This will indicate whether this filectx represents a file that is *not* in a
changectx. This will be used by merge and filemerge code to know about when a
conflict is a change/delete conflict.
While this is kind of hacky, it is the least bad of all the alternatives. Other
options considered but rejected include:
- isinstance(fctx, ...) -- not very Pythonic, doesn't support duck typing
- fctx.size() is None -- the 'size()' call on workingfilectxes causes a disk stat
- fctx.filenode() == nullid -- the semantics around filenode are incredibly
confusing. In particular, for workingfilectxes, filenode() is always None no
matter whether the file is present on disk or in either parent. Having different
behavior for None versus nullid in the merge code is just asking for pain.
Thanks to Pierre-Yves David for early review feedback here.
Test for changeset ba7c74081861
(update dirstate correctly for non-branchmerge updates)
$ hg init a
$ cd a
$ echo a > a
$ hg add a
$ hg commit -m a
$ cd ..
$ hg clone a b
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd a
$ hg mv a b
$ hg commit -m move
$ echo b >> b
$ hg commit -m b
$ cd ../b
$ hg pull ../a
pulling from ../a
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
(run 'hg update' to get a working copy)
$ hg update
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cd ..