view tests/test-1993.t @ 27372:a79cba6cb206

help: add documentation for changegroup formats

There is no formal location for spec-like technical/internal docs. The
repository makes sense as such a location because spec-like
documentation should be reviewed (ruling out a wiki). mpm has also
stated that he would like this documentation to be part of the
built-in help system. So, we establish an "internals" sub-directory
to hold this class of documentation.

The format of changegroups does not appear to be documented anywhere,
even in source code. It therefore seemed like an appropriate first thing
to document.

This patch adds low-level documentation of versions 1 and 2 of the
changegroup foromat. It currently only describes the raw data format.
There is probably room to write higher-level documentation on strategies
for producing and consuming the data. We'll leave that for another day.

The added file is not yet accessible via `hg help` nor via hgweb.
Support for this will follow in subsequent patches.

  $ hg init a
  $ cd a
  $ echo a > a
  $ hg ci -Am0
  adding a
  $ echo b > b
  $ hg ci -Am1
  adding b
  $ hg tag -r0 default
  warning: tag default conflicts with existing branch name
  $ hg log
  changeset:   2:30a83d1e4a1e
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added tag default for changeset f7b1eb17ad24
  
  changeset:   1:925d80f479bb
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  
  changeset:   0:f7b1eb17ad24
  tag:         default
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  $ hg update 'tag(default)'
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg parents
  changeset:   0:f7b1eb17ad24
  tag:         default
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  $ hg update 'branch(default)'
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg parents
  changeset:   2:30a83d1e4a1e
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added tag default for changeset f7b1eb17ad24
  

  $ cd ..