view tests/test-obsolete-bounds-checking.t @ 47682:78f7f0d490ee

dirstate-v2: Move fixed-size tree metadata into the docket file

Before this changeset, the dirstate-v2 data file contained not only nodes
and paths that may be reused when appending to an existing file,
but also some fixed-size metadata that applies to the entire tree
and was added at the end of the data file for every append.

This moves that metadata into the docket file, so that repeated "append"
operations without meaningful changes don’t actually need to grow any file.

Differential Revision: https://phab.mercurial-scm.org/D11098

Create a repo, set the username to something more than 255 bytes, then run hg amend on it.

  $ unset HGUSER
  $ cat >> $HGRCPATH << EOF
  > [ui]
  > username = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa <[e-mail]>
  > [extensions]
  > amend =
  > [experimental]
  > evolution.createmarkers=True
  > evolution.exchange=True
  > EOF
  $ hg init tmpa
  $ cd tmpa
  $ echo a > a
  $ hg add
  adding a
  $ hg commit -m "Initial commit"
  $ echo a >> a
  $ hg amend 2>&1 | egrep -v '^(\*\*|  )'
  transaction abort!
  rollback completed
  Traceback (most recent call last):
  *ProgrammingError: obsstore metadata value cannot be longer than 255 bytes (value "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa <[e-mail]>" for key "user" is 285 bytes) (glob)