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 9fe267f77f56ff127cf7e65dc15dd9de71ce8ceb
(merge correctly when all the files in a directory are moved
but then local changes are added in the same directory)
$ hg init a
$ cd a
$ mkdir -p testdir
$ echo a > testdir/a
$ hg add testdir/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
$ echo alpha > testdir/a
$ hg commit -m remote-change
$ cd ..
$ cd b
$ mkdir testdir/subdir
$ hg mv testdir/a testdir/subdir/a
$ hg commit -m move
$ mkdir newdir
$ echo beta > newdir/beta
$ hg add newdir/beta
$ hg commit -m local-addition
$ hg pull ../a
pulling from ../a
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg up -C 2
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge
merging testdir/subdir/a and testdir/a to testdir/subdir/a
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg stat
M testdir/subdir/a
$ hg diff --nodates
diff -r bc21c9773bfa testdir/subdir/a
--- a/testdir/subdir/a
+++ b/testdir/subdir/a
@@ -1,1 +1,1 @@
-a
+alpha
$ cd ..