view tests/test-narrow-copies.t @ 39409:2fe21c65777e

internals: document CBOR utilization

I spoke with some people at Mozilla about CBOR and they advised me
that we should be careful about the subset of CBOR we use in order
to mitigate security, performance, and compatibility concerns.

This commit establishes a document that attempts to formalize our
use of CBOR.

Its main limitations are on what types are allowed. It explicitly
enumerates which types are supported. Notable missing features
include:

* Indefinite-length arrays and maps
* Text strings (bytes all the way)
* Floats
* Date/time types
* Big integers
* Use of indefinite-length byte strings for map keys, values in
  containers.

If we have a need for any of these, we can have a discussion about
them when the time comes.

Differential Revision: https://phab.mercurial-scm.org/D4412

  $ . "$TESTDIR/narrow-library.sh"

create full repo

  $ hg init master
  $ cd master

  $ mkdir inside
  $ echo inside > inside/f1
  $ mkdir outside
  $ echo outside > outside/f2
  $ hg ci -Aqm 'initial'

  $ hg mv outside/f2 inside/f2
  $ hg ci -qm 'move f2 from outside'

  $ echo modified > inside/f2
  $ hg ci -qm 'modify inside/f2'

  $ cd ..

  $ hg clone --narrow ssh://user@dummy/master narrow --include inside
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 2 files
  new changesets *:* (glob)
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd narrow

  $ hg co 'desc("move f2")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg status
  $ hg diff
  $ hg diff --change . --git
  diff --git a/inside/f2 b/inside/f2
  new file mode 100644
  --- /dev/null
  +++ b/inside/f2
  @@ -0,0 +1,1 @@
  +outside

  $ hg log --follow inside/f2 -r tip
  changeset:   2:bcfb756e0ca9
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify inside/f2
  
  changeset:   1:5a016133b2bb
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     move f2 from outside