view tests/test-mq-qdelete.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.

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

  $ hg init a
  $ cd a

  $ echo 'base' > base
  $ hg ci -Ambase -d '1 0'
  adding base

  $ hg qnew -d '1 0' pa
  $ hg qnew -d '1 0' pb
  $ hg qnew -d '1 0' pc

  $ hg qdel
  abort: qdelete requires at least one revision or patch name
  [255]

  $ hg qdel pc
  abort: cannot delete applied patch pc
  [255]

  $ hg qpop
  popping pc
  now at: pb

Delete the same patch twice in one command (issue2427)

  $ hg qdel pc pc

  $ hg qseries
  pa
  pb

  $ ls .hg/patches
  pa
  pb
  series
  status

  $ hg qpop
  popping pb
  now at: pa

  $ hg qdel -k 1

  $ ls .hg/patches
  pa
  pb
  series
  status

  $ hg qdel -r pa
  patch pa finalized without changeset message

  $ hg qapplied

  $ hg log --template '{rev} {desc}\n'
  1 [mq]: pa
  0 base

  $ hg qnew pd
  $ hg qnew pe
  $ hg qnew pf

  $ hg qdel -r pe
  abort: cannot delete revision 3 above applied patches
  [255]

  $ hg qdel -r qbase:pe
  patch pd finalized without changeset message
  patch pe finalized without changeset message

  $ hg qapplied
  pf

  $ hg log --template '{rev} {desc}\n'
  4 [mq]: pf
  3 [mq]: pe
  2 [mq]: pd
  1 [mq]: pa
  0 base

  $ cd ..

  $ hg init b
  $ cd b

  $ echo 'base' > base
  $ hg ci -Ambase -d '1 0'
  adding base

  $ hg qfinish
  abort: no revisions specified
  [255]

  $ hg qfinish -a
  no patches applied

  $ hg qnew -d '1 0' pa
  $ hg qnew -d '1 0' pb
  $ hg qnew pc # XXX fails to apply by /usr/bin/patch if we put a date

  $ hg qfinish 0
  abort: revision 0 is not managed
  [255]

  $ hg qfinish pb
  abort: cannot delete revision 2 above applied patches
  [255]

  $ hg qpop
  popping pc
  now at: pb

  $ hg qfinish -a pc
  abort: unknown revision 'pc'!
  [255]

  $ hg qpush
  applying pc
  patch pc is empty
  now at: pc

  $ hg qfinish qbase:pb
  patch pa finalized without changeset message
  patch pb finalized without changeset message

  $ hg qapplied
  pc

  $ hg log --template '{rev} {desc}\n'
  3 imported patch pc
  2 [mq]: pb
  1 [mq]: pa
  0 base

  $ hg qfinish -a pc
  patch pc finalized without changeset message

  $ hg qapplied

  $ hg log --template '{rev} {desc}\n'
  3 imported patch pc
  2 [mq]: pb
  1 [mq]: pa
  0 base

  $ ls .hg/patches
  series
  status

qdel -k X && hg qimp -e X used to trigger spurious output with versioned queues

  $ hg init --mq
  $ hg qimport -r 3
  $ hg qpop
  popping 3.diff
  patch queue now empty
  $ hg qdel -k 3.diff
  $ hg qimp -e 3.diff
  adding 3.diff to series file
  $ hg qfinish -a
  no patches applied


resilience to inconsistency: qfinish -a with applied patches not in series

  $ hg qser
  3.diff
  $ hg qapplied
  $ hg qpush
  applying 3.diff
  patch 3.diff is empty
  now at: 3.diff
  $ echo next >>  base
  $ hg qrefresh -d '1 0'
  $ echo > .hg/patches/series # remove 3.diff from series to confuse mq
  $ hg qfinish -a
  revision 47dfa8501675 refers to unknown patches: 3.diff

more complex state 'both known and unknown patches

  $ echo hip >>  base
  $ hg qnew -f -d '1 0' -m 4 4.diff
  $ echo hop >>  base
  $ hg qnew -f -d '1 0' -m 5 5.diff
  $ echo > .hg/patches/series # remove 4.diff and 5.diff from series to confuse mq
  $ echo hup >>  base
  $ hg qnew -f -d '1 0' -m 6 6.diff
  $ echo pup > base
  $ hg qfinish -a
  warning: uncommitted changes in the working directory
  revision 2b1c98802260 refers to unknown patches: 5.diff
  revision 33a6861311c0 refers to unknown patches: 4.diff

  $ cd ..