view tests/test-blackbox.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.

setup
  $ cat > mock.py <<EOF
  > from mercurial import util
  > 
  > def makedate():
  >     return 0, 0
  > def getuser():
  >     return 'bob'
  > # mock the date and user apis so the output is always the same
  > def uisetup(ui):
  >     util.makedate = makedate
  >     util.getuser = getuser
  > EOF
  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > blackbox=
  > mock=`pwd`/mock.py
  > mq=
  > EOF
  $ hg init blackboxtest
  $ cd blackboxtest

command, exit codes, and duration

  $ echo a > a
  $ hg add a
  $ hg blackbox
  1970/01/01 00:00:00 bob> add a
  1970/01/01 00:00:00 bob> add a exited 0 after * seconds (glob)

incoming change tracking

create two heads to verify that we only see one change in the log later
  $ hg commit -ma
  $ hg up null
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo b > b
  $ hg commit -Amb
  adding b
  created new head

clone, commit, pull
  $ hg clone . ../blackboxtest2
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo c > c
  $ hg commit -Amc
  adding c
  $ cd ../blackboxtest2
  $ hg pull
  pulling from $TESTTMP/blackboxtest (glob)
  searching for 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 blackbox -l 5
  1970/01/01 00:00:00 bob> pull
  1970/01/01 00:00:00 bob> updated served branch cache in ?.???? seconds (glob)
  1970/01/01 00:00:00 bob> wrote served branch cache with 1 labels and 2 nodes
  1970/01/01 00:00:00 bob> 1 incoming changes - new heads: d02f48003e62
  1970/01/01 00:00:00 bob> pull exited 0 after * seconds (glob)

we must not cause a failure if we cannot write to the log

  $ hg rollback
  repository tip rolled back to revision 1 (undo pull)

#if unix-permissions no-root
  $ chmod 000 .hg/blackbox.log
  $ hg --debug incoming
  warning: cannot write to blackbox.log: Permission denied
  comparing with $TESTTMP/blackboxtest (glob)
  query 1; heads
  searching for changes
  all local heads known remotely
  changeset:   2:d02f48003e62c24e2659d97d30f2a83abe5d5d51
  tag:         tip
  phase:       draft
  parent:      1:6563da9dcf87b1949716e38ff3e3dfaa3198eb06
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    2:ab9d46b053ebf45b7996f2922b9893ff4b63d892
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files+:      c
  extra:       branch=default
  description:
  c
  
  
#endif
  $ hg pull
  pulling from $TESTTMP/blackboxtest (glob)
  searching for 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)

a failure reading from the log is fine
#if unix-permissions no-root
  $ hg blackbox -l 3
  abort: Permission denied: $TESTTMP/blackboxtest2/.hg/blackbox.log
  [255]

  $ chmod 600 .hg/blackbox.log
#endif

backup bundles get logged

  $ touch d
  $ hg commit -Amd
  adding d
  created new head
  $ hg strip tip
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  saved backup bundle to $TESTTMP/blackboxtest2/.hg/strip-backup/*-backup.hg (glob)
  $ hg blackbox -l 5
  1970/01/01 00:00:00 bob> strip tip
  1970/01/01 00:00:00 bob> saved backup bundle to $TESTTMP/blackboxtest2/.hg/strip-backup/*-backup.hg (glob)
  1970/01/01 00:00:00 bob> updated base branch cache in ?.???? seconds (glob)
  1970/01/01 00:00:00 bob> wrote base branch cache with 1 labels and 2 nodes
  1970/01/01 00:00:00 bob> strip tip exited 0 after * seconds (glob)

tags cache gets logged
  $ hg up tip
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg tag -m 'create test tag' test-tag
  $ hg tags
  tip                                3:5b5562c08298
  test-tag                           2:d02f48003e62
  $ hg blackbox -l 3
  1970/01/01 00:00:00 bob> resolved 1 tags cache entries from 1 manifests in ?.???? seconds (glob)
  1970/01/01 00:00:00 bob> writing tags cache file with 2 heads and 1 tags
  1970/01/01 00:00:00 bob> tags exited 0 after ?.?? seconds (glob)

extension and python hooks - use the eol extension for a pythonhook

  $ echo '[extensions]' >> .hg/hgrc
  $ echo 'eol=' >> .hg/hgrc
  $ echo '[hooks]' >> .hg/hgrc
  $ echo 'update = echo hooked' >> .hg/hgrc
  $ hg update
  hooked
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg blackbox -l 4
  1970/01/01 00:00:00 bob> update
  1970/01/01 00:00:00 bob> pythonhook-preupdate: hgext.eol.preupdate finished in * seconds (glob)
  1970/01/01 00:00:00 bob> exthook-update: echo hooked finished in * seconds (glob)
  1970/01/01 00:00:00 bob> update exited 0 after * seconds (glob)

log rotation

  $ echo '[blackbox]' >> .hg/hgrc
  $ echo 'maxsize = 20 b' >> .hg/hgrc
  $ echo 'maxfiles = 3' >> .hg/hgrc
  $ hg status
  $ hg status
  $ hg status
  $ hg tip -q
  3:5b5562c08298
  $ ls .hg/blackbox.log*
  .hg/blackbox.log
  .hg/blackbox.log.1
  .hg/blackbox.log.2

cleanup
  $ cd ..