tests/test-hgrc.t

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.

hide outer repo
  $ hg init

Use hgrc within $TESTTMP

  $ HGRCPATH=`pwd`/hgrc
  $ export HGRCPATH

Use an alternate var for scribbling on hgrc to keep check-code from
complaining about the important settings we may be overwriting:

  $ HGRC=`pwd`/hgrc
  $ export HGRC

Basic syntax error

  $ echo "invalid" > $HGRC
  $ hg version
  hg: parse error at $TESTTMP/hgrc:1: invalid
  [255]
  $ echo "" > $HGRC

Issue1199: Can't use '%' in hgrc (eg url encoded username)

  $ hg init "foo%bar"
  $ hg clone "foo%bar" foobar
  updating to branch default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd foobar
  $ cat .hg/hgrc
  # example repository config (see "hg help config" for more info)
  [paths]
  default = $TESTTMP/foo%bar (glob)
  
  # path aliases to other clones of this repo in URLs or filesystem paths
  # (see "hg help config.paths" for more info)
  #
  # default-push = ssh://[e-mail]/hg/jdoes-fork
  # my-fork      = ssh://[e-mail]/hg/jdoes-fork
  # my-clone     = /home/jdoe/jdoes-clone
  
  [ui]
  # name and email (local to this repository, optional), e.g.
  # username = Jane Doe <[e-mail]>
  $ hg paths
  default = $TESTTMP/foo%bar (glob)
  $ hg showconfig
  bundle.mainreporoot=$TESTTMP/foobar (glob)
  paths.default=$TESTTMP/foo%bar (glob)
  $ cd ..

issue1829: wrong indentation

  $ echo '[foo]' > $HGRC
  $ echo '  x = y' >> $HGRC
  $ hg version
  hg: parse error at $TESTTMP/hgrc:2:   x = y
  unexpected leading whitespace
  [255]

  $ $PYTHON -c "print '[foo]\nbar = a\n b\n c \n  de\n fg \nbaz = bif cb \n'" \
  > > $HGRC
  $ hg showconfig foo
  foo.bar=a\nb\nc\nde\nfg
  foo.baz=bif cb

  $ FAKEPATH=/path/to/nowhere
  $ export FAKEPATH
  $ echo '%include $FAKEPATH/no-such-file' > $HGRC
  $ hg version
  Mercurial Distributed SCM (version *) (glob)
  (see http://mercurial.selenic.com for more information)
  
  Copyright (C) 2005-2014 Matt Mackall and others
  This is free software; see the source for copying conditions. There is NO
  warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  $ unset FAKEPATH

make sure global options given on the cmdline take precedence

  $ hg showconfig --config ui.verbose=True --quiet
  bundle.mainreporoot=$TESTTMP
  ui.verbose=False
  ui.debug=False
  ui.quiet=True

  $ touch foobar/untracked
  $ cat >> foobar/.hg/hgrc <<EOF
  > [ui]
  > verbose=True
  > EOF
  $ hg -R foobar st -q

username expansion

  $ olduser=$HGUSER
  $ unset HGUSER

  $ FAKEUSER='John Doe'
  $ export FAKEUSER
  $ echo '[ui]' > $HGRC
  $ echo 'username = $FAKEUSER' >> $HGRC

  $ hg init usertest
  $ cd usertest
  $ touch bar
  $ hg commit --addremove --quiet -m "added bar"
  $ hg log --template "{author}\n"
  John Doe
  $ cd ..

  $ hg showconfig
  bundle.mainreporoot=$TESTTMP
  ui.username=$FAKEUSER

  $ unset FAKEUSER
  $ HGUSER=$olduser
  $ export HGUSER

showconfig with multiple arguments

  $ echo "[alias]" > $HGRC
  $ echo "log = log -g" >> $HGRC
  $ echo "[defaults]" >> $HGRC
  $ echo "identify = -n" >> $HGRC
  $ hg showconfig alias defaults
  alias.log=log -g
  defaults.identify=-n
  $ hg showconfig alias defaults.identify
  abort: only one config item permitted
  [255]
  $ hg showconfig alias.log defaults.identify
  abort: only one config item permitted
  [255]

HGPLAIN

  $ echo "[ui]" > $HGRC
  $ echo "debug=true" >> $HGRC
  $ echo "fallbackencoding=ASCII" >> $HGRC
  $ echo "quiet=true" >> $HGRC
  $ echo "slash=true" >> $HGRC
  $ echo "traceback=true" >> $HGRC
  $ echo "verbose=true" >> $HGRC
  $ echo "style=~/.hgstyle" >> $HGRC
  $ echo "logtemplate={node}" >> $HGRC
  $ echo "[defaults]" >> $HGRC
  $ echo "identify=-n" >> $HGRC
  $ echo "[alias]" >> $HGRC
  $ echo "log=log -g" >> $HGRC

customized hgrc

  $ hg showconfig
  read config from: $TESTTMP/hgrc
  $TESTTMP/hgrc:13: alias.log=log -g
  repo: bundle.mainreporoot=$TESTTMP
  $TESTTMP/hgrc:11: defaults.identify=-n
  $TESTTMP/hgrc:2: ui.debug=true
  $TESTTMP/hgrc:3: ui.fallbackencoding=ASCII
  $TESTTMP/hgrc:4: ui.quiet=true
  $TESTTMP/hgrc:5: ui.slash=true
  $TESTTMP/hgrc:6: ui.traceback=true
  $TESTTMP/hgrc:7: ui.verbose=true
  $TESTTMP/hgrc:8: ui.style=~/.hgstyle
  $TESTTMP/hgrc:9: ui.logtemplate={node}

plain hgrc

  $ HGPLAIN=; export HGPLAIN
  $ hg showconfig --config ui.traceback=True --debug
  read config from: $TESTTMP/hgrc
  repo: bundle.mainreporoot=$TESTTMP
  --config: ui.traceback=True
  --verbose: ui.verbose=False
  --debug: ui.debug=True
  --quiet: ui.quiet=False

plain mode with exceptions

  $ cat > plain.py <<EOF
  > def uisetup(ui):
  >     ui.write('plain: %r\n' % ui.plain())
  > EOF
  $ echo "[extensions]" >> $HGRC
  $ echo "plain=./plain.py" >> $HGRC
  $ HGPLAINEXCEPT=; export HGPLAINEXCEPT
  $ hg showconfig --config ui.traceback=True --debug
  plain: True
  read config from: $TESTTMP/hgrc
  repo: bundle.mainreporoot=$TESTTMP
  $TESTTMP/hgrc:15: extensions.plain=./plain.py
  --config: ui.traceback=True
  --verbose: ui.verbose=False
  --debug: ui.debug=True
  --quiet: ui.quiet=False
  $ unset HGPLAIN
  $ hg showconfig --config ui.traceback=True --debug
  plain: True
  read config from: $TESTTMP/hgrc
  repo: bundle.mainreporoot=$TESTTMP
  $TESTTMP/hgrc:15: extensions.plain=./plain.py
  --config: ui.traceback=True
  --verbose: ui.verbose=False
  --debug: ui.debug=True
  --quiet: ui.quiet=False
  $ HGPLAINEXCEPT=i18n; export HGPLAINEXCEPT
  $ hg showconfig --config ui.traceback=True --debug
  plain: True
  read config from: $TESTTMP/hgrc
  repo: bundle.mainreporoot=$TESTTMP
  $TESTTMP/hgrc:15: extensions.plain=./plain.py
  --config: ui.traceback=True
  --verbose: ui.verbose=False
  --debug: ui.debug=True
  --quiet: ui.quiet=False

source of paths is not mangled

  $ cat >> $HGRCPATH <<EOF
  > [paths]
  > foo = bar
  > EOF
  $ hg showconfig --debug paths
  plain: True
  read config from: $TESTTMP/hgrc
  $TESTTMP/hgrc:17: paths.foo=$TESTTMP/bar (glob)