view tests/test-contrib-check-commit.t @ 32697:19b9fc40cc51

revlog: skeleton support for version 2 revlogs

There are a number of improvements we want to make to revlogs
that will require a new version - version 2. It is unclear what the
full set of improvements will be or when we'll be done with them.
What I do know is that the process will likely take longer than a
single release, will require input from various stakeholders to
evaluate changes, and will have many contentious debates and
bikeshedding.

It is unrealistic to develop revlog version 2 up front: there
are just too many uncertainties that we won't know until things
are implemented and experiments are run. Some changes will also
be invasive and prone to bit rot, so sitting on dozens of patches
is not practical.

This commit introduces skeleton support for version 2 revlogs in
a way that is flexible and not bound by backwards compatibility
concerns.

An experimental repo requirement for denoting revlog v2 has been
added. The requirement string has a sub-version component to it.
This will allow us to declare multiple requirements in the course
of developing revlog v2. Whenever we change the in-development
revlog v2 format, we can tweak the string, creating a new
requirement and locking out old clients. This will allow us to
make as many backwards incompatible changes and experiments to
revlog v2 as we want. In other words, we can land code and make
meaningful progress towards revlog v2 while still maintaining
extreme format flexibility up until the point we freeze the
format and remove the experimental labels.

To enable the new repo requirement, you must supply an experimental
and undocumented config option. But not just any boolean flag
will do: you need to explicitly use a value that no sane person
should ever type. This is an additional guard against enabling
revlog v2 on an installation it shouldn't be enabled on. The
specific scenario I'm trying to prevent is say a user with a
4.4 client with a frozen format enabling the option but then
downgrading to 4.3 and accidentally creating repos with an
outdated and unsupported repo format. Requiring a "challenge"
string should prevent this.

Because the format is not yet finalized and I don't want to take
any chances, revlog v2's version is currently 0xDEAD. I figure
squatting on a value we're likely never to use as an actual revlog
version to mean "internal testing only" is acceptable. And
"dead" is easily recognized as something meaningful.

There is a bunch of cleanup that is needed before work on revlog
v2 begins in earnest. I plan on doing that work once this patch
is accepted and we're comfortable with the idea of starting down
this path.

Test the 'check-commit' script
==============================

A fine patch:

  $ cat > patch-with-long-header.diff << EOF
  > # HG changeset patch
  > # User timeless <[e-mail]>
  > # Date 1448911706 0
  > #      Mon Nov 30 19:28:26 2015 +0000
  > # Node ID c41cb6d2b7dbd62b1033727f8606b8c09fc4aa88
  > # Parent  42aa0e570eaa364a622bc4443b0bcb79b1100a58
  > # ClownJoke This is a veryly long header that should not be warned about because its not the description
  > bundle2: use Oxford comma (issue123) (BC)
  > 
  > diff --git a/hgext/transplant.py b/hgext/transplant.py
  > --- a/hgext/transplant.py
  > +++ b/hgext/transplant.py
  > @@ -599,7 +599,7 @@
  >              return
  >          if not (opts.get('source') or revs or
  >                  opts.get('merge') or opts.get('branch')):
  > -            raise error.Abort(_('no source URL, branch revision or revision '
  > +            raise error.Abort(_('no source URL, branch revision, or revision '
  >                                 'list provided'))
  >          if opts.get('all'):
  > 
  > + def blahblah(x):
  > +     pass
  > EOF
  $ cat patch-with-long-header.diff | $TESTDIR/../contrib/check-commit

This would normally be against the rules, but it's okay because that's
what tagging and signing looks like:

  $ cat > creates-a-tag.diff << EOF
  > # HG changeset patch
  > # User Augie Fackler <[e-mail]>
  > # Date 1484787778 18000
  > #      Wed Jan 18 20:02:58 2017 -0500
  > # Branch stable
  > # Node ID c177635e4acf52923bc3aa9f72a5b1ad1197b173
  > # Parent  a1dd2c0c479e0550040542e392e87bc91262517e
  > Added tag 4.1-rc for changeset a1dd2c0c479e
  > 
  > diff --git a/.hgtags b/.hgtags
  > --- a/.hgtags
  > +++ b/.hgtags
  > @@ -150,3 +150,4 @@ 438173c415874f6ac653efc1099dec9c9150e90f
  >  eab27446995210c334c3d06f1a659e3b9b5da769 4.0
  >  b3b1ae98f6a0e14c1e1ba806a6c18e193b6dae5c 4.0.1
  >  e69874dc1f4e142746ff3df91e678a09c6fc208c 4.0.2
  > +a1dd2c0c479e0550040542e392e87bc91262517e 4.1-rc
  > EOF
  $ $TESTDIR/../contrib/check-commit < creates-a-tag.diff

A patch with lots of errors:

  $ cat > patch-with-long-header.diff << EOF
  > # HG changeset patch
  > # User timeless
  > # Date 1448911706 0
  > #      Mon Nov 30 19:28:26 2015 +0000
  > # Node ID c41cb6d2b7dbd62b1033727f8606b8c09fc4aa88
  > # Parent  42aa0e570eaa364a622bc4443b0bcb79b1100a58
  > # ClownJoke This is a veryly long header that should not be warned about because its not the description
  > transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
  > 
  > diff --git a/hgext/transplant.py b/hgext/transplant.py
  > --- a/hgext/transplant.py
  > +++ b/hgext/transplant.py
  > @@ -599,7 +599,7 @@
  >              return
  >          if not (opts.get('source') or revs or
  >                  opts.get('merge') or opts.get('branch')):
  > -            raise error.Abort(_('no source URL, branch revision or revision '
  > +            raise error.Abort(_('no source URL, branch revision, or revision '
  >                                 'list provided'))
  >          if opts.get('all'):
  > EOF
  $ cat patch-with-long-header.diff | $TESTDIR/../contrib/check-commit
  1: username is not an email address
   # User timeless
  7: summary keyword should be most user-relevant one-word command or topic
   transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
  7: (BC) needs to be uppercase
   transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
  7: use (issueDDDD) instead of bug
   transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
  7: no space allowed between issue and number
   transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
  7: summary line too long (limit is 78)
   transplant/foo: this summary is way too long use Oxford comma (bc) (bug123) (issue 244)
  [1]

A patch with other errors:

  $ cat > patch-with-long-header.diff << EOF
  > # HG changeset patch
  > # User timeless
  > # Date 1448911706 0
  > #      Mon Nov 30 19:28:26 2015 +0000
  > # Node ID c41cb6d2b7dbd62b1033727f8606b8c09fc4aa88
  > # Parent  42aa0e570eaa364a622bc4443b0bcb79b1100a58
  > # ClownJoke This is a veryly long header that should not be warned about because its not the description
  > This has no topic and ends with a period.
  > 
  > diff --git a/hgext/transplant.py b/hgext/transplant.py
  > --- a/hgext/transplant.py
  > +++ b/hgext/transplant.py
  > @@ -599,7 +599,7 @@
  >          if opts.get('all'):
  >  
  > 
  > +
  > + some = otherjunk
  > +
  > +
  > + def blah_blah(x):
  > +     pass
  > +
  >  
  > EOF
  $ cat patch-with-long-header.diff | $TESTDIR/../contrib/check-commit
  1: username is not an email address
   # User timeless
  7: don't capitalize summary lines
   This has no topic and ends with a period.
  7: summary line doesn't start with 'topic: '
   This has no topic and ends with a period.
  7: don't add trailing period on summary line
   This has no topic and ends with a period.
  19: adds double empty line
   +
  20: adds a function with foo_bar naming
   + def blah_blah(x):
  23: adds double empty line
   +
  [1]