filelog: raise CensoredNodeError when hash checks fail with censor metadata
With this change, when a revlog revision hash does not match its content, and
the content is empty with a special metadata key, the integrity failure is
assumed to be intentionally caused to remove sensitive content from repository
history.
To allow different Mercurial functionality to handle this scenario differently
a more specific exception is raised than "ordinary" hash failures.
Alternatives to this approach include, but are not limited to:
- Calling a hook when hashes mismatch to allow arbitrary tombstone validation.
Cons: Irresponsibly easy to disable integrity checking altogether.
- Returning empty revision data eagerly instead of raising, masking the error.
Cons: Push/pull won't roundtrip the tombstone, so client repos are unusable.
- Doing nothing differently at this layer. Callers must do their own detection
of tombstoned data if they want to handle some hash checks and not others.
- Impacts dozens of callsites, many of which don't have the revision data
- Would probably be missing one or two callsites at any given time
- Currently we throw a RevlogError, as do 12 other places in revlog.py.
Callers would need to parse the exception message and/or ensure
RevlogError is not thrown from any other part of their call tree.
Issue586: removing remote files after merge appears to corrupt the
dirstate
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Ama
adding a
$ hg init ../b
$ cd ../b
$ echo b > b
$ hg ci -Amb
adding b
$ hg pull -f ../a
pulling from ../a
searching for changes
warning: repository is unrelated
requesting all 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 merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg rm -f a
$ hg ci -Amc
$ hg st -A
C b
$ cd ..
Issue1433: Traceback after two unrelated pull, two move, a merge and
a commit (related to issue586)
create test repos
$ hg init repoa
$ touch repoa/a
$ hg -R repoa ci -Am adda
adding a
$ hg init repob
$ touch repob/b
$ hg -R repob ci -Am addb
adding b
$ hg init repoc
$ cd repoc
$ hg pull ../repoa
pulling from ../repoa
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
(run 'hg update' to get a working copy)
$ hg update
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ mkdir tst
$ hg mv * tst
$ hg ci -m "import a in tst"
$ hg pull -f ../repob
pulling from ../repob
searching for changes
warning: repository is unrelated
requesting all 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)
merge both repos
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ mkdir src
move b content
$ hg mv b src
$ hg ci -m "import b in src"
$ hg manifest
src/b
tst/a
$ cd ..