Fix zombie files in merge
# HG changeset patch
# User maf46@burn.cl.cam.ac.uk
# Node ID 57667c9b93a5a743e4629d15a0e6bd76699130c3
# Parent d2994b5298fb20f87dc1d4747635b280db3c0526
Fix zombie files in merge
Keir Fraser observed the following:
> I made a small test case that illustrates the bug in merging changesets
> with 'hg remove's in them:
>
> 1. Create a repository A containing files foo & bar.
> 2. Create clone called B.
> 3. A removes file bar, and commits this removal.
> 4. B edits file foo, and commits this edit.
>
> Now, if B:
> # hg pull ../A; hg update -m; hg commit
> Then bar remains deleted.
>
> If A:
> # hg pull ../B; hg update -m; hg commit
> Then bar is resurrected!
>
> It looks as though, when you merge across a branch, any deletions in
> your own branch are forgotten.
> ...
> Fixing this is a must, as zombie files are a real pain. :-)
Keir later patched our local copy of hg as shown below, which fixes
the problem. I've also enclosed a test which captures the test Keir
outlined...
Files deleted on a branch should not automatically reappear in a merge
Patch notes:
1. The first chunk does not change behaviour, but cleans up the code
to more closely match check of 'force' in the second chunk. I
think it makes the code clearer.
2. The second chunk fixes two bugs --
i. If we choose to keep a remotely-changed locally-deleted file,
then we need to 'get' that file. If we choose to delete it
then no action need be taken (it is already deleted in the
working manifest). Without this fix, choosing to delete would
get a Python traceback.
ii. The test for whether the file was remotely-created is
insufficient. It is only true if f is not in the common
ancestor. Otherwise the file was deleted locally, and should
remain deleted. (this is the most important fix!)
Index: hg/tests/test-merge6
===================================================================
Mercurial git BK (*)
storage revlog delta compressed revisions SCCS weave
storage naming by filename by revision hash by filename
merge file DAGs changeset DAG file DAGs?
consistency SHA1 SHA1 CRC
signable? yes yes no
retrieve file tip O(1) O(1) O(revs)
add rev O(1) O(1) O(revs)
find prev file rev O(1) O(changesets) O(revs)
annotate file O(revs) O(changesets) O(revs)
find file changeset O(1) O(changesets) ?
checkout O(files) O(files) O(revs)?
commit O(changes) O(changes) ?
6 patches/s 6 patches/s slow
diff working dir O(changes) O(changes) ?
< 1s < 1s ?
tree diff revs O(changes) O(changes) ?
< 1s < 1s ?
hardlink clone O(files) O(revisions) O(files)
find remote csets O(log new) rsync: O(revisions) ?
git-http: O(changesets)
pull remote csets O(patch) O(modified files) O(patch)
repo growth O(patch) O(revisions) O(patch)
kernel history 300M 3.5G? 250M?
lines of code 2500 6500 (+ cogito) ??
* I've never used BK so this is just guesses