view tests/test-bookflow.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

initialize
  $ make_changes() {
  >     d=`pwd`
  >     [ ! -z $1 ] && cd $1
  >     echo "test `basename \`pwd\``" >> test
  >     hg commit -Am"${2:-test}"
  >     r=$?
  >     cd $d
  >     return $r
  > }
  $ ls -1a
  .
  ..
  $ hg init a
  $ cd a
  $ echo 'test' > test; hg commit -Am'test'
  adding test

clone to b

  $ mkdir ../b
  $ cd ../b
  $ hg clone ../a .
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo "[extensions]" >> .hg/hgrc
  $ echo "bookflow=" >> .hg/hgrc
  $ hg branch X
  abort: creating named branches is disabled and you should use bookmarks
  (see 'hg help bookflow')
  [255]
  $ hg bookmark X
  $ hg bookmarks
  * X                         0:* (glob)
  $ hg bookmark X
  abort: bookmark X already exists, to move use the --rev option
  [255]
  $ make_changes
  $ hg push ../a -q

  $ hg bookmarks
   \* X                         1:* (glob)

change a
  $ cd ../a
  $ hg up
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo 'test' >> test; hg commit -Am'test'


pull in b
  $ cd ../b
  $ hg pull -u
  pulling from $TESTTMP/a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets * (glob)
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (leaving bookmark X)
  $ hg status
  $ hg bookmarks
     X                         1:* (glob)

check protection of @ bookmark
  $ hg bookmark @
  $ hg bookmarks
   \* @                         2:* (glob)
     X                         1:* (glob)
  $ make_changes
  abort: cannot commit, bookmark @ is protected
  [255]

  $ hg status
  M test
  $ hg bookmarks
   \* @                         2:* (glob)
     X                         1:* (glob)

  $ hg --config bookflow.protect= commit  -Am"Updated test"

  $ hg bookmarks
   \* @                         3:* (glob)
     X                         1:* (glob)

check requirement for an active bookmark
  $ hg bookmark -i
  $ hg bookmarks
     @                         3:* (glob)
     X                         1:* (glob)
  $ make_changes
  abort: cannot commit without an active bookmark
  [255]
  $ hg revert test
  $ rm test.orig
  $ hg status


make the bookmark move by updating it on a, and then pulling
# add a commit to a
  $ cd ../a
  $ hg bookmark X
  $ hg bookmarks
   \* X                         2:* (glob)
  $ make_changes
  $ hg bookmarks
   * X                         3:81af7977fdb9

# go back to b, and check out X
  $ cd ../b
  $ hg up X
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (activating bookmark X)
  $ hg bookmarks
     @                         3:* (glob)
   \* X                         1:* (glob)

# pull, this should move the bookmark forward, because it was changed remotely
  $ hg pull -u | grep "updating to active bookmark X"
  updating to active bookmark X

  $ hg bookmarks
     @                         3:* (glob)
   * X                         4:81af7977fdb9

the bookmark should not move if it diverged from remote
  $ hg -R ../a status
  $ hg -R ../b status
  $ make_changes ../a
  $ make_changes ../b
  $ hg -R ../a status
  $ hg -R ../b status
  $ hg -R ../a bookmarks
   * X                         4:238292f60a57
  $ hg -R ../b bookmarks
     @                         3:* (glob)
   * X                         5:096f7e86892d
  $ cd ../b
  $ # make sure we cannot push after bookmarks diverged
  $ hg push -B X | grep abort
  abort: push creates new remote head * with bookmark 'X' (glob)
  (pull and merge or see 'hg help push' for details about pushing new heads)
  [1]
  $ hg pull -u | grep divergent
  divergent bookmark X stored as X@default
  1 other divergent bookmarks for "X"
  $ hg bookmarks
     @                         3:* (glob)
   * X                         5:096f7e86892d
     X@default                 6:238292f60a57
  $ hg id -in
  096f7e86892d 5
  $ make_changes
  $ hg status
  $ hg bookmarks
     @                         3:* (glob)
   * X                         7:227f941aeb07
     X@default                 6:238292f60a57

now merge with the remote bookmark
  $ hg merge X@default --tool :local -q
  $ hg status
  M test
  $ hg commit -m"Merged with X@default"
  $ hg bookmarks
     @                         3:* (glob)
   * X                         8:26fed9bb3219
  $ hg push -B X | grep bookmark
  pushing to $TESTTMP/a (?)
  updating bookmark X
  $ cd ../a
  $ hg up -q
  $ hg bookmarks
   * X                         7:26fed9bb3219

test hg pull when there is more than one descendant
  $ cd ../a
  $ hg bookmark Z
  $ hg bookmark Y
  $ make_changes . YY
  $ hg up Z -q
  $ make_changes . ZZ
  created new head
  $ hg bookmarks
     X                         7:26fed9bb3219
     Y                         8:131e663dbd2a
   * Z                         9:b74a4149df25
  $ hg log -r 'p1(Y)' -r 'p1(Z)' -T '{rev}\n' # prove that Y and Z share the same parent
  7
  $ hg log -r 'Y%Z' -T '{rev}\n'  # revs in Y but not in Z
  8
  $ hg log -r 'Z%Y' -T '{rev}\n'  # revs in Z but not in Y
  9
  $ cd ../b
  $ hg pull -uq
  $ hg id
  b74a4149df25 tip Z
  $ hg bookmarks | grep \*  # no active bookmark
  [1]


test shelving
  $ cd ../a
  $ echo anotherfile > anotherfile # this change should not conflict
  $ hg add anotherfile
  $ hg commit -m"Change in a"
  $ cd ../b
  $ hg up Z | grep Z
  (activating bookmark Z)
  $ hg book | grep \* # make sure active bookmark
   \* Z                         10:* (glob)
  $ echo "test b" >> test
  $ hg diff --stat
   test |  1 +
   1 files changed, 1 insertions(+), 0 deletions(-)
  $ hg shelve
  shelved as Z
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg pull -uq
  $ hg unshelve
  unshelving change 'Z'
  rebasing shelved changes
  $ hg diff --stat
   test |  1 +
   1 files changed, 1 insertions(+), 0 deletions(-)


make the bookmark move by updating it on a, and then pulling with a local change
# add a commit to a
  $ cd ../a
  $ hg up -C X |fgrep  "activating bookmark X"
  (activating bookmark X)
# go back to b, and check out X
  $ cd ../b
  $ hg up -C X |fgrep  "activating bookmark X"
  (activating bookmark X)
# update and push from a
  $ make_changes ../a
  created new head
  $ echo "more" >> test
  $ hg pull -u 2>&1 | fgrep -v TESTTMP| fgrep -v "searching for changes" | fgrep -v adding
  pulling from $TESTTMP/a
  updating bookmark X
  added 1 changesets with 0 changes to 0 files (+1 heads)
  new changesets * (glob)
  updating to active bookmark X
  merging test
  warning: conflicts while merging test! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges
  $ hg update -Cq
  $ rm test.orig

make sure that commits aren't possible if working directory is not pointing to active bookmark
  $ hg -R ../a status
  $ hg -R ../b status
  $ hg -R ../a id -i
  36a6e592ec06
  $ hg -R ../a book | grep X
   \* X                         \d+:36a6e592ec06 (re)
  $ hg -R ../b id -i
  36a6e592ec06
  $ hg -R ../b book | grep X
   \* X                         \d+:36a6e592ec06 (re)
  $ make_changes ../a
  $ hg -R ../a book | grep X
   \* X                         \d+:f73a71c992b8 (re)
  $ cd ../b
  $ hg pull  2>&1 | grep -v add | grep -v pulling | grep -v searching | grep -v changeset
  updating bookmark X
  (run 'hg update' to get a working copy)
  working directory out of sync with active bookmark, run 'hg up X'
  $ hg id -i # we're still on the old commit
  36a6e592ec06
  $ hg book | grep X # while the bookmark moved
   \* X                         \d+:f73a71c992b8 (re)
  $ make_changes
  abort: cannot commit, working directory out of sync with active bookmark
  (run 'hg up X')
  [255]
  $ hg up -Cq -r .  # cleanup local changes
  $ hg status
  $ hg id -i # we're still on the old commit
  36a6e592ec06
  $ hg up X -q
  $ hg id -i # now we're on X
  f73a71c992b8
  $ hg book | grep X
   \* X                         \d+:f73a71c992b8 (re)