view tests/test-share.t @ 23702:c48924787eaa

filectx.parents: enforce changeid of parent to be in own changectx ancestors

Because of the way filenodes are computed, you can have multiple changesets
"introducing" the same file revision. For example, in the changeset graph
below, changeset 2 and 3 both change a file -to- and -from- the same content.

  o 3: content = new
  |
  | o 2: content = new
  |/
  o 1: content = old

In such cases, the file revision is create once, when 2 is added, and just reused
for 3. So the file change in '3' (from "old" to "new)" has no linkrev pointing
to it).  We'll call this situation "linkrev-shadowing". As the linkrev is used for
optimization purposes when walking a file history, the linkrev-shadowing
results in an unexpected jump to another branch during such a walk.. This leads to
multiple bugs with log, annotate and rename detection.

One element to fix such bugs is to ensure that walking the file history sticks on
the same topology as the changeset's history. For this purpose, we extend the
logic in 'basefilectx.parents' so that it always defines the proper changeset
to associate the parent file revision with. This "proper" changeset has to be an
ancestor of the changeset associated with the child file revision.

This logic is performed in the '_adjustlinkrev' function. This function is
given the starting changeset and all the information regarding the parent file
revision. If the linkrev for the file revision is an ancestor of the starting
changeset, the linkrev is valid and will be used. If it is not, we detected a
topological jump caused by linkrev shadowing, we are going to walk the
ancestors of the starting changeset until we find one setting the file to the
revision we are trying to create.

The performance impact appears acceptable:

- We are walking the changelog once for each filelog traversal (as there should
  be no overlap between searches),

- changelog traversal itself is fairly cheap, compared to what is likely going
  to be perform on the result on the filelog traversal,

- We only touch the manifest for ancestors touching the file, And such
  changesets are likely to be the one introducing the file. (except in
  pathological cases involving merge),

- We use manifest diff instead of full manifest unpacking to check manifest
  content, so it does not involve applying multiple diffs in most case.

- linkrev shadowing is not the common case.

Tests for fixed issues in log, annotate and rename detection have been
added.

But this changeset does not solve all problems. It fixes -ancestry-
computation, but if the linkrev-shadowed changesets is the starting one, we'll
still get things wrong. We'll have to fix the bootstrapping of such operations
in a later changeset. Also, the usage of `hg log FILE`  without --follow still
has issues with linkrev pointing to hidden changesets, because it relies on the
`filelog` revset which implement its own traversal logic that is still to be
fixed.

Thanks goes to:
- Matt Mackall: for nudging me in the right direction
- Julien Cristau and Rémi Cardona: for keep telling me linkrev bug were an
  evolution show stopper for 3 years.
- Durham Goode: for finding a new linkrev issue every few weeks
- Mads Kiilerich: for that last rename bug who raise this topic over my
  anoyance limit.

#require killdaemons

  $ echo "[extensions]"      >> $HGRCPATH
  $ echo "share = "          >> $HGRCPATH

prepare repo1

  $ hg init repo1
  $ cd repo1
  $ echo a > a
  $ hg commit -A -m'init'
  adding a

share it

  $ cd ..
  $ hg share repo1 repo2
  updating working directory
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

share shouldn't have a store dir

  $ cd repo2
  $ test -d .hg/store
  [1]

Some sed versions appends newline, some don't, and some just fails

  $ cat .hg/sharedpath; echo
  $TESTTMP/repo1/.hg (glob)

trailing newline on .hg/sharedpath is ok
  $ hg tip -q
  0:d3873e73d99e
  $ echo '' >> .hg/sharedpath
  $ cat .hg/sharedpath
  $TESTTMP/repo1/.hg (glob)
  $ hg tip -q
  0:d3873e73d99e

commit in shared clone

  $ echo a >> a
  $ hg commit -m'change in shared clone'

check original

  $ cd ../repo1
  $ hg log
  changeset:   1:8af4dc49db9e
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change in shared clone
  
  changeset:   0:d3873e73d99e
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     init
  
  $ hg update
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat a             # should be two lines of "a"
  a
  a

commit in original

  $ echo b > b
  $ hg commit -A -m'another file'
  adding b

check in shared clone

  $ cd ../repo2
  $ hg log
  changeset:   2:c2e0ac586386
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     another file
  
  changeset:   1:8af4dc49db9e
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     change in shared clone
  
  changeset:   0:d3873e73d99e
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     init
  
  $ hg update
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat b             # should exist with one "b"
  b

hg serve shared clone

  $ hg serve -n test -p $HGPORT -d --pid-file=hg.pid
  $ cat hg.pid >> $DAEMON_PIDS
  $ "$TESTDIR/get-with-headers.py" localhost:$HGPORT 'raw-file/'
  200 Script output follows
  
  
  -rw-r--r-- 4 a
  -rw-r--r-- 2 b
  
  

test unshare command

  $ hg unshare
  $ test -d .hg/store
  $ test -f .hg/sharedpath
  [1]
  $ hg unshare
  abort: this is not a shared repo
  [255]

check that a change does not propagate

  $ echo b >> b
  $ hg commit -m'change in unshared'
  $ cd ../repo1
  $ hg id -r tip
  c2e0ac586386 tip

  $ cd ..


test sharing bookmarks

  $ hg share -B repo1 repo3
  updating working directory
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd repo1
  $ hg bookmark bm1
  $ hg bookmarks
   * bm1                       2:c2e0ac586386
  $ cd ../repo2
  $ hg book bm2
  $ hg bookmarks
   * bm2                       3:0e6e70d1d5f1
  $ cd ../repo3
  $ hg bookmarks
     bm1                       2:c2e0ac586386
  $ hg book bm3
  $ hg bookmarks
     bm1                       2:c2e0ac586386
   * bm3                       2:c2e0ac586386
  $ cd ../repo1
  $ hg bookmarks
   * bm1                       2:c2e0ac586386
     bm3                       2:c2e0ac586386

test that commits work

  $ echo 'shared bookmarks' > a
  $ hg commit -m 'testing shared bookmarks'
  $ hg bookmarks
   * bm1                       3:b87954705719
     bm3                       2:c2e0ac586386
  $ cd ../repo3
  $ hg bookmarks
     bm1                       3:b87954705719
   * bm3                       2:c2e0ac586386
  $ echo 'more shared bookmarks' > a
  $ hg commit -m 'testing shared bookmarks'
  created new head
  $ hg bookmarks
     bm1                       3:b87954705719
   * bm3                       4:62f4ded848e4
  $ cd ../repo1
  $ hg bookmarks
   * bm1                       3:b87954705719
     bm3                       4:62f4ded848e4
  $ cd ..

test pushing bookmarks works

  $ hg clone repo3 repo4
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd repo4
  $ hg boo bm4
  $ echo foo > b
  $ hg commit -m 'foo in b'
  $ hg boo
     bm1                       3:b87954705719
     bm3                       4:62f4ded848e4
   * bm4                       5:92793bfc8cad
  $ hg push -B bm4
  pushing to $TESTTMP/repo3 (glob)
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  exporting bookmark bm4
  $ cd ../repo1
  $ hg bookmarks
   * bm1                       3:b87954705719
     bm3                       4:62f4ded848e4
     bm4                       5:92793bfc8cad
  $ cd ../repo3
  $ hg bookmarks
     bm1                       3:b87954705719
   * bm3                       4:62f4ded848e4
     bm4                       5:92793bfc8cad
  $ cd ..

test behavior when sharing a shared repo

  $ hg share -B repo3 repo5
  updating working directory
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd repo5
  $ hg book
     bm1                       3:b87954705719
     bm3                       4:62f4ded848e4
     bm4                       5:92793bfc8cad
  $ cd ..

test what happens when an active bookmark is deleted

  $ cd repo1
  $ hg boo -d bm3
  $ hg boo
   * bm1                       3:b87954705719
     bm4                       5:92793bfc8cad
  $ cd ../repo3
  $ hg boo
     bm1                       3:b87954705719
     bm4                       5:92793bfc8cad
  $ cd ..

verify that bookmarks are not written on failed transaction

  $ cat > failpullbookmarks.py << EOF
  > """A small extension that makes bookmark pulls fail, for testing"""
  > from mercurial import extensions, exchange, error
  > def _pullbookmarks(orig, pullop):
  >     orig(pullop)
  >     raise error.HookAbort('forced failure by extension')
  > def extsetup(ui):
  >     extensions.wrapfunction(exchange, '_pullbookmarks', _pullbookmarks)
  > EOF
  $ cd repo4
  $ hg boo
     bm1                       3:b87954705719
     bm3                       4:62f4ded848e4
   * bm4                       5:92793bfc8cad
  $ cd ../repo3
  $ hg boo
     bm1                       3:b87954705719
     bm4                       5:92793bfc8cad
  $ hg --config "extensions.failpullbookmarks=$TESTTMP/failpullbookmarks.py" pull $TESTTMP/repo4
  pulling from $TESTTMP/repo4 (glob)
  searching for changes
  no changes found
  adding remote bookmark bm3
  abort: forced failure by extension
  [255]
  $ hg boo
     bm1                       3:b87954705719
     bm4                       5:92793bfc8cad
  $ hg pull $TESTTMP/repo4
  pulling from $TESTTMP/repo4 (glob)
  searching for changes
  no changes found
  adding remote bookmark bm3
  $ hg boo
     bm1                       3:b87954705719
   * bm3                       4:62f4ded848e4
     bm4                       5:92793bfc8cad
  $ cd ..

verify bookmark behavior after unshare

  $ cd repo3
  $ hg unshare
  $ hg boo
     bm1                       3:b87954705719
   * bm3                       4:62f4ded848e4
     bm4                       5:92793bfc8cad
  $ hg boo -d bm4
  $ hg boo bm5
  $ hg boo
     bm1                       3:b87954705719
     bm3                       4:62f4ded848e4
   * bm5                       4:62f4ded848e4
  $ cd ../repo1
  $ hg boo
   * bm1                       3:b87954705719
     bm3                       4:62f4ded848e4
     bm4                       5:92793bfc8cad
  $ cd ..

Explicitly kill daemons to let the test exit on Windows

  $ "$TESTDIR/killdaemons.py" $DAEMON_PIDS