Mercurial > hg
view tests/test-merge1.t @ 46607:e9901d01d135
revlog: add a mechanism to verify expected file position before appending
If someone uses `hg debuglocks`, or some non-hg process writes to the .hg
directory without respecting the locks, or if the repo's on a networked
filesystem, it's possible for the revlog code to write out corrupted data.
The form of this corruption can vary depending on what data was written and how
that happened. We are in the "networked filesystem" case (though I've had users
also do this to themselves with the "`hg debuglocks`" scenario), and most often
see this with the changelog. What ends up happening is we produce two items
(let's call them rev1 and rev2) in the .i file that have the same linkrev,
baserev, and offset into the .d file, while the data in the .d file is appended
properly. rev2's compressed_size is accurate for rev2, but when we go to
decompress the data in the .d file, we use the offset that's recorded in the
index file, which is the same as rev1, and attempt to decompress
rev2.compressed_size bytes of rev1's data. This usually does not succeed. :)
When using inline data, this also fails, though I haven't investigated why too
closely. This shows up as a "patch decode" error. I believe what's happening
there is that we're basically ignoring the offset field, getting the data
properly, but since baserev != rev, it thinks this is a delta based on rev
(instead of a full text) and can't actually apply it as such.
For now, I'm going to make this an optional component and default it to entirely
off. I may increase the default severity of this in the future, once I've
enabled it for my users and we gain more experience with it. Luckily, most of my
users have a versioned filesystem and can roll back to before the corruption has
been written, it's just a hassle to do so and not everyone knows how (so it's a
support burden). Users on other filesystems will not have that luxury, and this
can cause them to have a corrupted repository that they are unlikely to know how
to resolve, and they'll see this as a data-loss event. Refusing to create the
corruption is a much better user experience.
This mechanism is not perfect. There may be false-negatives (racy writes that
are not detected). There should not be any false-positives (non-racy writes that
are detected as such). This is not a mechanism that makes putting a repo on a
networked filesystem "safe" or "supported", just *less* likely to cause
corruption.
Differential Revision: https://phab.mercurial-scm.org/D9952
author | Kyle Lippincott <spectral@google.com> |
---|---|
date | Wed, 03 Feb 2021 16:33:10 -0800 |
parents | dc00324e80f4 |
children | 434de12918fd |
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$ cat <<EOF > merge > from __future__ import print_function > import sys, os > > try: > import msvcrt > msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY) > msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY) > except ImportError: > pass > > print("merging for", os.path.basename(sys.argv[1])) > EOF $ HGMERGE="\"$PYTHON\" ../merge"; export HGMERGE $ hg init t $ cd t $ echo This is file a1 > a $ hg add a $ hg commit -m "commit #0" $ echo This is file b1 > b $ hg add b $ hg commit -m "commit #1" $ hg update 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved Test interrupted updates by having a non-empty dir with the same name as one of the files in a commit we're updating to $ mkdir b && touch b/nonempty $ hg up abort: Unlinking directory not permitted: *$TESTTMP/t/b* (glob) (windows !) abort: Directory not empty: '?\$TESTTMP/t/b'? (re) (no-windows !) [255] $ hg ci abort: last update was interrupted (use 'hg update' to get a consistent checkout) [20] $ hg sum parent: 0:538afb845929 commit #0 branch: default commit: 1 unknown (interrupted update) update: 1 new changesets (update) phases: 2 draft Detect interrupted update by hg status --verbose $ hg status -v ? b/nonempty # The repository is in an unfinished *update* state. # To continue: hg update . $ rm b/nonempty $ hg up 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg sum parent: 1:b8bb4a988f25 tip commit #1 branch: default commit: (clean) update: (current) phases: 2 draft Prepare a basic merge $ hg up 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo This is file c1 > c $ hg add c $ hg commit -m "commit #2" created new head $ echo This is file b1 > b no merges expected $ hg merge -P 1 changeset: 1:b8bb4a988f25 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: commit #1 $ hg merge 1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg diff --nodates diff -r 49035e18a8e6 b --- /dev/null +++ b/b @@ -0,0 +1,1 @@ +This is file b1 $ hg status M b $ cd ..; rm -r t $ hg init t $ cd t $ echo This is file a1 > a $ hg add a $ hg commit -m "commit #0" $ echo This is file b1 > b $ hg add b $ hg commit -m "commit #1" $ hg update 0 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo This is file c1 > c $ hg add c $ hg commit -m "commit #2" created new head $ echo This is file b2 > b merge should fail $ hg merge 1 b: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] #if symlink symlinks to directories should be treated as regular files (issue5027) $ rm b $ ln -s 'This is file b2' b $ hg merge 1 b: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] symlinks shouldn't be followed $ rm b $ echo This is file b1 > .hg/b $ ln -s .hg/b b $ hg merge 1 b: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] $ rm b $ echo This is file b2 > b #endif bad config $ hg merge 1 --config merge.checkunknown=x config error: merge.checkunknown not valid ('x' is none of 'abort', 'ignore', 'warn') [30] this merge should fail $ hg merge 1 --config merge.checkunknown=abort b: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] this merge should warn $ hg merge 1 --config merge.checkunknown=warn b: replacing untracked file 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat b.orig This is file b2 $ hg up --clean 2 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ mv b.orig b this merge should silently ignore $ cat b This is file b2 $ hg merge 1 --config merge.checkunknown=ignore 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) merge.checkignored $ hg up --clean 1 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ cat >> .hgignore << EOF > remoteignored > EOF $ echo This is file localignored3 > localignored $ echo This is file remoteignored3 > remoteignored $ hg add .hgignore localignored remoteignored $ hg commit -m "commit #3" $ hg up 2 1 files updated, 0 files merged, 4 files removed, 0 files unresolved $ cat >> .hgignore << EOF > localignored > EOF $ hg add .hgignore $ hg commit -m "commit #4" remote .hgignore shouldn't be used for determining whether a file is ignored $ echo This is file remoteignored4 > remoteignored $ hg merge 3 --config merge.checkignored=ignore --config merge.checkunknown=abort remoteignored: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] $ hg merge 3 --config merge.checkignored=abort --config merge.checkunknown=ignore merging .hgignore merging for .hgignore 3 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat remoteignored This is file remoteignored3 $ cat remoteignored.orig This is file remoteignored4 $ rm remoteignored.orig local .hgignore should be used for that $ hg up --clean 4 1 files updated, 0 files merged, 3 files removed, 0 files unresolved $ echo This is file localignored4 > localignored also test other conflicting files to see we output the full set of warnings $ echo This is file b2 > b $ hg merge 3 --config merge.checkignored=abort --config merge.checkunknown=abort b: untracked file differs localignored: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] $ hg merge 3 --config merge.checkignored=abort --config merge.checkunknown=ignore localignored: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] $ hg merge 3 --config merge.checkignored=warn --config merge.checkunknown=abort b: untracked file differs abort: untracked files in working directory differ from files in requested revision [20] $ hg merge 3 --config merge.checkignored=warn --config merge.checkunknown=warn b: replacing untracked file localignored: replacing untracked file merging .hgignore merging for .hgignore 3 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ cat localignored This is file localignored3 $ cat localignored.orig This is file localignored4 $ rm localignored.orig $ cat b.orig This is file b2 $ hg up --clean 2 0 files updated, 0 files merged, 4 files removed, 0 files unresolved $ mv b.orig b this merge of b should work $ cat b This is file b2 $ hg merge -f 1 merging b merging for b 0 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg diff --nodates diff -r 49035e18a8e6 b --- /dev/null +++ b/b @@ -0,0 +1,1 @@ +This is file b2 $ hg status M b $ cd ..; rm -r t $ hg init t $ cd t $ echo This is file a1 > a $ hg add a $ hg commit -m "commit #0" $ echo This is file b1 > b $ hg add b $ hg commit -m "commit #1" $ echo This is file b22 > b $ hg commit -m "commit #2" $ hg update 1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo This is file c1 > c $ hg add c $ hg commit -m "commit #3" created new head Contents of b should be "this is file b1" $ cat b This is file b1 $ echo This is file b22 > b merge fails $ hg merge 2 abort: uncommitted changes (use 'hg status' to list changes) [20] merge expected! $ hg merge -f 2 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg diff --nodates diff -r 85de557015a8 b --- a/b +++ b/b @@ -1,1 +1,1 @@ -This is file b1 +This is file b22 $ hg status M b $ cd ..; rm -r t $ hg init t $ cd t $ echo This is file a1 > a $ hg add a $ hg commit -m "commit #0" $ echo This is file b1 > b $ hg add b $ hg commit -m "commit #1" $ echo This is file b22 > b $ hg commit -m "commit #2" $ hg update 1 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo This is file c1 > c $ hg add c $ hg commit -m "commit #3" created new head $ echo This is file b33 > b merge of b should fail $ hg merge 2 abort: uncommitted changes (use 'hg status' to list changes) [20] merge of b expected $ hg merge -f 2 merging b merging for b 0 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg diff --nodates diff -r 85de557015a8 b --- a/b +++ b/b @@ -1,1 +1,1 @@ -This is file b1 +This is file b33 $ hg status M b Test for issue2364 $ hg up -qC . $ hg rm b $ hg ci -md $ hg revert -r -2 b $ hg up -q -- -2 Test that updated files are treated as "modified", when 'merge.update()' is aborted before 'merge.recordupdates()' (= parents aren't changed), even if none of mode, size and timestamp of them isn't changed on the filesystem (see also issue4583). $ cat > $TESTTMP/abort.py <<EOF > from __future__ import absolute_import > # emulate aborting before "recordupdates()". in this case, files > # are changed without updating dirstate > from mercurial import ( > error, > extensions, > merge, > ) > def applyupdates(orig, *args, **kwargs): > orig(*args, **kwargs) > raise error.Abort(b'intentional aborting') > def extsetup(ui): > extensions.wrapfunction(merge, "applyupdates", applyupdates) > EOF $ cat >> .hg/hgrc <<EOF > [fakedirstatewritetime] > # emulate invoking dirstate.write() via repo.status() > # at 2000-01-01 00:00 > fakenow = 200001010000 > EOF (file gotten from other revision) $ hg update -q -C 2 $ echo 'THIS IS FILE B5' > b $ hg commit -m 'commit #5' $ hg update -q -C 3 $ cat b This is file b1 $ touch -t 200001010000 b $ hg debugrebuildstate $ cat >> .hg/hgrc <<EOF > [extensions] > fakedirstatewritetime = $TESTDIR/fakedirstatewritetime.py > abort = $TESTTMP/abort.py > EOF $ hg merge 5 abort: intentional aborting [255] $ cat >> .hg/hgrc <<EOF > [extensions] > fakedirstatewritetime = ! > abort = ! > EOF $ cat b THIS IS FILE B5 $ touch -t 200001010000 b $ hg status -A b M b (file merged from other revision) $ hg update -q -C 3 $ echo 'this is file b6' > b $ hg commit -m 'commit #6' created new head $ cat b this is file b6 $ touch -t 200001010000 b $ hg debugrebuildstate $ cat >> .hg/hgrc <<EOF > [extensions] > fakedirstatewritetime = $TESTDIR/fakedirstatewritetime.py > abort = $TESTTMP/abort.py > EOF $ hg merge --tool internal:other 5 abort: intentional aborting [255] $ cat >> .hg/hgrc <<EOF > [extensions] > fakedirstatewritetime = ! > abort = ! > EOF $ cat b THIS IS FILE B5 $ touch -t 200001010000 b $ hg status -A b M b $ cd ..