Mercurial > hg
view tests/test-branch-change.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 | 95c4cca641f6 |
children | 7a90fddb13b0 |
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Testing changing branch on commits ================================== Setup $ cat >> $HGRCPATH << EOF > [alias] > glog = log -G -T "{rev}:{node|short} {desc}\n{branch} ({bookmarks})" > [experimental] > evolution = createmarkers > [extensions] > rebase= > EOF $ hg init repo $ cd repo $ for ch in a b c d e; do echo foo >> $ch; hg ci -Aqm "Added "$ch; done $ hg glog @ 4:aa98ab95a928 Added e | default () o 3:62615734edd5 Added d | default () o 2:28ad74487de9 Added c | default () o 1:29becc82797a Added b | default () o 0:18d04c59bb5d Added a default () $ hg branches default 4:aa98ab95a928 Try without passing a new branch name $ hg branch -r . abort: no branch name specified for the revisions [10] Setting an invalid branch name $ hg branch -r . a:b abort: ':' cannot be used in a name [10] $ hg branch -r . tip abort: the name 'tip' is reserved [10] $ hg branch -r . 1234 abort: cannot use an integer as a name [10] Change on non-linear set of commits $ hg branch -r 2 -r 4 foo abort: cannot change branch of non-linear revisions [10] Change in middle of the stack (linear commits) $ hg branch -r 1::3 foo abort: cannot change branch of changeset with children [10] Change with dirty working directory $ echo bar > a $ hg branch -r . foo abort: uncommitted changes [20] $ hg revert --all reverting a Change on empty revision set $ hg branch -r 'draft() - all()' foo abort: empty revision set [10] Changing branch on linear set of commits from head Without obsmarkers $ hg branch -r 3:4 foo --config experimental.evolution=! changed branch on 2 changesets saved backup bundle to $TESTTMP/repo/.hg/strip-backup/62615734edd5-e86bd13a-branch-change.hg $ hg glog @ 4:3938acfb5c0f Added e | foo () o 3:9435da006bdc Added d | foo () o 2:28ad74487de9 Added c | default () o 1:29becc82797a Added b | default () o 0:18d04c59bb5d Added a default () $ hg branches foo 4:3938acfb5c0f default 2:28ad74487de9 (inactive) With obsmarkers $ hg branch -r 3::4 bar changed branch on 2 changesets $ hg glog @ 6:7c1991464886 Added e | bar () o 5:1ea05e93925f Added d | bar () o 2:28ad74487de9 Added c | default () o 1:29becc82797a Added b | default () o 0:18d04c59bb5d Added a default () $ hg branches bar 6:7c1991464886 default 2:28ad74487de9 (inactive) Change branch name to an existing branch $ hg branch -r . default abort: a branch of the same name already exists [10] Changing on a branch head which is not topological head $ hg branch -r 2 stable abort: cannot change branch of changeset with children [10] Enabling the allowunstable config and trying to change branch on a branch head which is not a topological head $ echo "[experimental]" >> .hg/hgrc $ echo "evolution.allowunstable=yes" >> .hg/hgrc $ hg branch -r 2 foo changed branch on 1 changesets 2 new orphan changesets Changing branch of an obsoleted changeset $ hg branch -r 4 foobar abort: hidden revision '4' was rewritten as: 7c1991464886 (use --hidden to access hidden revisions) [255] $ hg branch -r 4 --hidden foobar abort: cannot change branch of a obsolete changeset [10] Make sure bookmark movement is correct $ hg bookmark b1 $ hg glog -r '.^::' @ 6:7c1991464886 Added e | bar (b1) * 5:1ea05e93925f Added d | bar () ~ $ hg branch -r '(.^)::' wat --debug changing branch of '1ea05e93925f806d875a2163f9b76764be644636' from 'bar' to 'wat' committing files: d committing manifest committing changelog new node id is 343660ccab7400da637bd6a211d07f413536d718 changing branch of '7c19914648869f5b02fc7fed31ddee9783fdd680' from 'bar' to 'wat' committing files: e committing manifest committing changelog new node id is de1404b45a69f8cc6437d7679033ee33e9efb4ba moving bookmarks ['b1'] from 7c19914648869f5b02fc7fed31ddee9783fdd680 to de1404b45a69f8cc6437d7679033ee33e9efb4ba resolving manifests branchmerge: False, force: False, partial: False ancestor: 7c1991464886, local: 7c1991464886+, remote: de1404b45a69 starting 4 threads for background file closing (?) changed branch on 2 changesets updating the branch cache invalid branch cache (served): tip differs $ hg glog -r '(.^)::' @ 9:de1404b45a69 Added e | wat (b1) * 8:343660ccab74 Added d | wat () ~ Make sure phase handling is correct $ echo foo >> bar $ hg ci -Aqm "added bar" --secret 1 new orphan changesets $ hg glog -r . @ 10:8ad1294c1660 added bar | wat (b1) ~ $ hg branch -r . secret changed branch on 1 changesets $ hg phase -r . 11: secret $ hg branches secret 11:38a9b2d53f98 foo 7:8a4729a5e2b8 wat 9:de1404b45a69 (inactive) default 2:28ad74487de9 (inactive) $ hg branch secret Changing branch of another head, different from one on which we are $ hg glog @ 11:38a9b2d53f98 added bar | secret (b1) * 9:de1404b45a69 Added e | wat () * 8:343660ccab74 Added d | wat () | o 7:8a4729a5e2b8 Added c | | foo () x | 2:28ad74487de9 Added c |/ default () o 1:29becc82797a Added b | default () o 0:18d04c59bb5d Added a default () $ hg branch secret $ hg branch -r 7 foobar changed branch on 1 changesets The current branch must be preserved $ hg branch secret Changing branch on multiple heads at once $ hg rebase -s 8 -d 12 --keepbranches -q $ hg rebase -s 14 -d 1 --keepbranches -q $ hg branch -r 0: stable changed branch on 6 changesets $ hg glog @ 23:6a5ddbcfb870 added bar | stable (b1) o 22:baedc6e98a67 Added e | stable () | o 21:99ac7bf8aad1 Added d | | stable () | o 20:0ecb4d39c4bd Added c |/ stable () o 19:fd45b986b109 Added b | stable () o 18:204d2769eca2 Added a stable () $ hg branches stable 23:6a5ddbcfb870 $ hg branch stable Changing to same branch is no-op $ hg branch -r 19::21 stable changed branch on 0 changesets Changing branch name to existing branch name if the branch of parent of root of revs is same as the new branch name $ hg branch -r 20::21 bugfix changed branch on 2 changesets $ hg glog o 25:714defe1cf34 Added d | bugfix () o 24:98394def28fc Added c | bugfix () | @ 23:6a5ddbcfb870 added bar | | stable (b1) | o 22:baedc6e98a67 Added e |/ stable () o 19:fd45b986b109 Added b | stable () o 18:204d2769eca2 Added a stable () $ hg branch -r 24:25 stable changed branch on 2 changesets $ hg glog o 27:4ec342341562 Added d | stable () o 26:83f48859c2de Added c | stable () | @ 23:6a5ddbcfb870 added bar | | stable (b1) | o 22:baedc6e98a67 Added e |/ stable () o 19:fd45b986b109 Added b | stable () o 18:204d2769eca2 Added a stable () Changing branch of a merge commit $ hg branch -q ghi $ echo f > f $ hg ci -qAm 'Added f' $ hg up -q 27 $ hg branch -q jkl $ echo g > g $ hg ci -qAm 'Added g' $ hg glog -r 'heads(:)' @ 29:6bc1c6c2c9da Added g | jkl () ~ o 28:2f1019bd29d2 Added f | ghi (b1) ~ $ hg branch -q default $ hg merge -r 28 4 files updated, 0 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg branch -r . abcd abort: outstanding uncommitted merge [20] $ hg ci -m "Merge commit" $ hg glog -r 'parents(.)::' @ 30:4d56e6b1eb6b Merge commit |\ default () | o 29:6bc1c6c2c9da Added g | | jkl () | ~ o 28:2f1019bd29d2 Added f | ghi (b1) ~ $ hg branch -r . ghi 0 files updated, 0 files merged, 4 files removed, 0 files unresolved changed branch on 1 changesets $ hg branch -r . jkl changed branch on 1 changesets $ hg branch -r . default changed branch on 1 changesets $ hg branch -r . stable abort: a branch of the same name already exists [10] $ hg branch -r . stable --force changed branch on 1 changesets $ hg branches stable 34:d1c2addda4a2 jkl 29:6bc1c6c2c9da (inactive) ghi 28:2f1019bd29d2 (inactive) Changing branch on public changeset $ hg phase -r . -p $ hg branch -r . def abort: cannot change branch of public changesets (see 'hg help phases' for details) [10] Merge commit with conflicts, with evolution and without $ mklozenge() { > echo foo > a > hg ci -qAm foo > echo bar > a > hg ci -qm bar > hg up -q '.^' > echo baz > a > hg ci -qm baz > hg merge -q -t :local > echo neither > a > hg ci -qm neither > } $ cd .. $ hg init merge-with-evolution $ cd merge-with-evolution $ mklozenge $ hg branch -r '(.^)::' abc changed branch on 2 changesets $ hg glog @ 5:c07fa8b34d54 neither |\ abc () | o 4:f2aa51777cc9 baz | | abc () o | 1:2e33c4f0856b bar |/ default () o 0:91cfb6004abf foo default () $ hg cat a neither $ cd .. $ hg init merge-without-evolution $ cd merge-without-evolution $ mklozenge $ cat > .hg/hgrc << EOF > [experimental] > evolution = no > evolution.allowunstable = no > EOF $ hg branch -r '(.^)::' abc changed branch on 2 changesets saved backup bundle to $TESTTMP/merge-without-evolution/.hg/strip-backup/9a3a2af368f4-8db1a361-branch-change.hg $ hg glog @ 3:c07fa8b34d54 neither |\ abc () | o 2:f2aa51777cc9 baz | | abc () o | 1:2e33c4f0856b bar |/ default () o 0:91cfb6004abf foo default () $ hg cat a neither