view tests/test-treediscovery-legacy.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

Tests discovery against servers without getbundle support:

  $ cat >> $HGRCPATH <<EOF
  > [ui]
  > logtemplate="{rev} {node|short}: {desc} {branches}\n"
  > EOF
  $ cp $HGRCPATH $HGRCPATH-withcap

  $ CAP="getbundle known changegroupsubset"
  $ . "$TESTDIR/notcapable"
  $ cp $HGRCPATH $HGRCPATH-nocap
  $ cp $HGRCPATH-withcap $HGRCPATH

Prep for test server without branchmap support

  $ CAP="branchmap"
  $ . "$TESTDIR/notcapable"
  $ cp $HGRCPATH $HGRCPATH-nocap-branchmap
  $ cp $HGRCPATH-withcap $HGRCPATH

Setup HTTP server control:

  $ remote=http://localhost:$HGPORT/
  $ export remote
  $ tstart() {
  >   echo '[web]' > $1/.hg/hgrc
  >   echo 'push_ssl = false' >> $1/.hg/hgrc
  >   echo 'allow_push = *' >> $1/.hg/hgrc
  >   cp $HGRCPATH-nocap $HGRCPATH
  >   hg serve -R $1 -p $HGPORT -d --pid-file=hg.pid -E errors.log
  >   cat hg.pid >> $DAEMON_PIDS
  > }
  $ tstop() {
  >   "$TESTDIR/killdaemons.py" $DAEMON_PIDS
  >   cp $HGRCPATH-withcap $HGRCPATH
  > }

Both are empty:

  $ hg init empty1
  $ hg init empty2
  $ tstart empty2
  $ hg incoming -R empty1 $remote
  comparing with http://localhost:$HGPORT/
  no changes found
  [1]
  $ hg outgoing -R empty1 $remote
  comparing with http://localhost:$HGPORT/
  no changes found
  [1]
  $ hg pull -R empty1 $remote
  pulling from http://localhost:$HGPORT/
  no changes found
  $ hg push -R empty1 $remote
  pushing to http://localhost:$HGPORT/
  no changes found
  [1]
  $ tstop

Base repo:

  $ hg init main
  $ cd main
  $ hg debugbuilddag -mo '+2:tbase @name1 +3:thead1 <tbase @name2 +4:thead2 @both /thead1 +2:tmaintip'
  $ hg log -G
  o  11 a19bfa7e7328: r11 both
  |
  o  10 8b6bad1512e1: r10 both
  |
  o    9 025829e08038: r9 both
  |\
  | o  8 d8f638ac69e9: r8 name2
  | |
  | o  7 b6b4d315a2ac: r7 name2
  | |
  | o  6 6c6f5d5f3c11: r6 name2
  | |
  | o  5 70314b29987d: r5 name2
  | |
  o |  4 e71dbbc70e03: r4 name1
  | |
  o |  3 2c8d5d5ec612: r3 name1
  | |
  o |  2 a7892891da29: r2 name1
  |/
  o  1 0019a3b924fd: r1
  |
  o  0 d57206cc072a: r0
  
  $ cd ..
  $ tstart main

Full clone:

  $ hg clone main full
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd full
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  no changes found
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Local is empty:

  $ cd empty1
  $ hg incoming $remote --rev name1
  comparing with http://localhost:$HGPORT/
  abort: cannot look up remote changes; remote repository does not support the 'changegroupsubset' capability!
  [255]
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  0 d57206cc072a: r0 
  1 0019a3b924fd: r1 
  2 a7892891da29: r2 name1
  3 2c8d5d5ec612: r3 name1
  4 e71dbbc70e03: r4 name1
  5 70314b29987d: r5 name2
  6 6c6f5d5f3c11: r6 name2
  7 b6b4d315a2ac: r7 name2
  8 d8f638ac69e9: r8 name2
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  no changes found
  [1]
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  no changes found
  [1]
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 12 changesets with 24 changes to 2 files
  (run 'hg update' to get a working copy)
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Local is subset:

  $ cp $HGRCPATH-withcap $HGRCPATH
  $ hg clone main subset --rev name2 ; cd subset
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 12 changes to 2 files
  updating to branch name2
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cp $HGRCPATH-nocap $HGRCPATH
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  6 a7892891da29: r2 name1
  7 2c8d5d5ec612: r3 name1
  8 e71dbbc70e03: r4 name1
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 12 changes to 2 files
  (run 'hg update' to get a working copy)
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Remote is empty:

  $ tstop ; tstart empty2
  $ cd main
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  0 d57206cc072a: r0 
  1 0019a3b924fd: r1 
  2 a7892891da29: r2 name1
  3 2c8d5d5ec612: r3 name1
  4 e71dbbc70e03: r4 name1
  5 70314b29987d: r5 name2
  6 6c6f5d5f3c11: r6 name2
  7 b6b4d315a2ac: r7 name2
  8 d8f638ac69e9: r8 name2
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  no changes found
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 12 changesets with 24 changes to 2 files
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Local is superset:

  $ tstop
  $ hg clone main subset2 --rev name2
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 12 changes to 2 files
  updating to branch name2
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ tstart subset2
  $ cd main
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  2 a7892891da29: r2 name1
  3 2c8d5d5ec612: r3 name1
  4 e71dbbc70e03: r4 name1
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  no changes found
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  abort: push creates new remote branches: both, name1!
  (use 'hg push --new-branch' to create new remote branches)
  [255]
  $ hg push $remote --new-branch
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 6 changesets with 12 changes to 2 files
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Partial pull:

  $ tstop ; tstart main
  $ hg clone $remote partial --rev name2
  abort: partial pull cannot be done because other repository doesn't support changegroupsubset.
  [255]
  $ hg init partial; cd partial
  $ hg incoming $remote --rev name2
  comparing with http://localhost:$HGPORT/
  abort: cannot look up remote changes; remote repository does not support the 'changegroupsubset' capability!
  [255]
  $ hg pull $remote --rev name2
  pulling from http://localhost:$HGPORT/
  abort: partial pull cannot be done because other repository doesn't support changegroupsubset.
  [255]
  $ cd ..

  $ tstop

Exercise pushing to server without branchmap capability

  $ cp $HGRCPATH-nocap-branchmap $HGRCPATH-nocap
  $ hg init rlocal
  $ cd rlocal
  $ echo A > A
  $ hg ci -Am A
  adding A
  $ cd ..
  $ hg clone rlocal rremote
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd rlocal
  $ echo B > B
  $ hg ci -Am B
  adding B
  $ cd ..
  $ tstart rremote

  $ cd rlocal
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  1 27547f69f254: B 
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  no changes found
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

  $ tstop