tests/test-transaction-safety.t

dirstate-v2: add check of parent/child nodes being related when writing

This stems from a corruption seen in a private repository. We're not sure
of the source of the corruption, and it's very possible that we're seeing
compounded effects of multiple writes on a corrupted dirstate.

Adding this check is not expensive in itself and large writes of the dirstate
are not common.

This change does not catch this problem at the root node, the next one will.

Test transaction safety
=======================

#testcases revlogv1 revlogv2 changelogv2

#if revlogv1

  $ cat << EOF >> $HGRCPATH
  > [experimental]
  > revlogv2=no
  > EOF

#endif

#if revlogv2

  $ cat << EOF >> $HGRCPATH
  > [experimental]
  > revlogv2=enable-unstable-format-and-corrupt-my-data
  > EOF

#endif

#if changelogv2

  $ cat << EOF >> $HGRCPATH
  > [format]
  > exp-use-changelog-v2=enable-unstable-format-and-corrupt-my-data
  > EOF

#endif

This test basic case to make sure external process do not see transaction
content until it is committed.

# TODO: also add an external reader accessing revlog files while they are written
#       (instead of during transaction finalisation)

# TODO: also add stream clone and hardlink clone happening during these transaction.

setup
-----

synchronisation+output script using the following schedule:

[A1] "external"       is started
[A2] "external"       waits on EXT_UNLOCK
[A2] "external"       + creates EXT_WAITING → unlocks [C1]
[B1] "hg commit/pull" is started
[B2] "hg commit/pull" is ready to be committed
[B3] "hg commit/pull" spawn "internal" using a pretxnclose hook (need [C4])
[C1] "internal"       waits on EXT_WAITING (need [A2])
[C2] "internal"       creates EXT_UNLOCK → unlocks [A2]
[C3] "internal"       show the tipmost revision (inside of the transaction)
[C4] "internal"       waits on EXT_DONE (need [A4])
[A3] "external"       show the tipmost revision (outside of the transaction)
[A4] "external"       creates EXT_DONE → unlocks [C4]
[C5] "internal"       end of execution -> unlock [B3]
[B4] "hg commit/pull" transaction is committed on disk


  $ mkdir sync
  $ mkdir output
  $ mkdir script
  $ HG_TEST_FILE_EXT_WAITING=$TESTTMP/sync/ext_waiting
  $ export HG_TEST_FILE_EXT_WAITING
  $ HG_TEST_FILE_EXT_UNLOCK=$TESTTMP/sync/ext_unlock
  $ export HG_TEST_FILE_EXT_UNLOCK
  $ HG_TEST_FILE_EXT_DONE=$TESTTMP/sync/ext_done
  $ export HG_TEST_FILE_EXT_DONE
  $ cat << EOF > script/external.sh
  > #!/bin/sh
  > "$RUNTESTDIR/testlib/wait-on-file" 5 "$HG_TEST_FILE_EXT_UNLOCK" "$HG_TEST_FILE_EXT_WAITING"
  > hg log --rev 'tip' -T 'external: {rev} {desc}\n' > "$TESTTMP/output/external.out"
  > touch "$HG_TEST_FILE_EXT_DONE"
  > EOF
  $ cat << EOF > script/internal.sh
  > #!/bin/sh
  > "$RUNTESTDIR/testlib/wait-on-file" 5 "$HG_TEST_FILE_EXT_WAITING"
  > touch "$HG_TEST_FILE_EXT_UNLOCK"
  > hg log --rev 'tip' -T 'internal: {rev} {desc}\n' > "$TESTTMP/output/internal.out"
  > "$RUNTESTDIR/testlib/wait-on-file" 5 "$HG_TEST_FILE_EXT_DONE"
  > EOF


Automated commands:

  $ make_one_commit() {
  > rm -f $TESTTMP/sync/*
  > rm -f $TESTTMP/output/*
  > hg log --rev 'tip' -T 'pre-commit: {rev} {desc}\n'
  > echo x >> of
  > sh $TESTTMP/script/external.sh & hg commit -m "$1"
  > cat $TESTTMP/output/external.out
  > cat $TESTTMP/output/internal.out
  > hg log --rev 'tip' -T 'post-tr:  {rev} {desc}\n'
  > }


  $ make_one_pull() {
  > rm -f $TESTTMP/sync/*
  > rm -f $TESTTMP/output/*
  > hg log --rev 'tip' -T 'pre-commit: {rev} {desc}\n'
  > echo x >> of
  > sh $TESTTMP/script/external.sh & hg pull ../other-repo/ --rev "$1" --force --quiet
  > cat $TESTTMP/output/external.out
  > cat $TESTTMP/output/internal.out
  > hg log --rev 'tip' -T 'post-tr:  {rev} {desc}\n'
  > }

prepare a large source to which to pull from:

The source is large to unsure we don't use inline more after the pull

  $ hg init other-repo
  $ hg -R other-repo debugbuilddag .+500 --overwritten-file


prepare an empty repository where to make test:

  $ hg init repo
  $ cd repo
  $ touch of
  $ hg add of

prepare a small extension to controll inline size

  $ mkdir $TESTTMP/ext
  $ cat << EOF > $TESTTMP/ext/small_inline.py
  > from mercurial import revlog
  > revlog._maxinline = 3 * 100
  > EOF




  $ cat << EOF >> $HGRCPATH
  > [extensions]
  > small_inline=$TESTTMP/ext/small_inline.py
  > [hooks]
  > pretxnclose = sh $TESTTMP/script/internal.sh
  > EOF

check this is true for the initial commit (inline → inline)
-----------------------------------------------------------

the repository should still be inline (for relevant format)

  $ make_one_commit first
  pre-commit: -1 
  external: -1 
  internal: 0 first
  post-tr:  0 first

#if revlogv1

  $ hg debugrevlog of | grep inline
  flags  : inline, * (glob)

#endif

check this is true for extra commit (inline → inline)
-----------------------------------------------------

the repository should still be inline (for relevant format)

#if revlogv1

  $ hg debugrevlog of | grep inline
  flags  : inline, * (glob)

#endif

  $ make_one_commit second
  pre-commit: 0 first
  external: 0 first
  internal: 1 second
  post-tr:  1 second

#if revlogv1

  $ hg debugrevlog of | grep inline
  flags  : inline, * (glob)

#endif

check this is true for a small pull (inline → inline)
-----------------------------------------------------

the repository should still be inline (for relevant format)

#if revlogv1

  $ hg debugrevlog of | grep inline
  flags  : inline, * (glob)

#endif

  $ make_one_pull 3
  pre-commit: 1 second
  warning: repository is unrelated
  external: 1 second
  internal: 5 r3
  post-tr:  5 r3

#if revlogv1

  $ hg debugrevlog of | grep inline
  flags  : inline, * (glob)

#endif

Make a large pull (inline → no-inline)
---------------------------------------

the repository should no longer be inline (for relevant format)

#if revlogv1

  $ hg debugrevlog of | grep inline
  flags  : inline, * (glob)

#endif

  $ make_one_pull 400
  pre-commit: 5 r3
  external: 5 r3
  internal: 402 r400
  post-tr:  402 r400

#if revlogv1

  $ hg debugrevlog of | grep inline
  [1]

#endif

check this is true for extra commit (no-inline → no-inline)
-----------------------------------------------------------

the repository should no longer be inline (for relevant format)

#if revlogv1

  $ hg debugrevlog of | grep inline
  [1]

#endif

  $ make_one_commit third
  pre-commit: 402 r400
  external: 402 r400
  internal: 403 third
  post-tr:  403 third

#if revlogv1

  $ hg debugrevlog of | grep inline
  [1]

#endif


Make a  pull (not-inline → no-inline)
-------------------------------------

the repository should no longer be inline (for relevant format)

#if revlogv1

  $ hg debugrevlog of | grep inline
  [1]

#endif

  $ make_one_pull tip
  pre-commit: 403 third
  external: 403 third
  internal: 503 r500
  post-tr:  503 r500

#if revlogv1

  $ hg debugrevlog of | grep inline
  [1]

#endif