view tests/test-dirstate-race.t @ 31996:e6e1884df298

track-tags: write all tag changes to a file

The tag changes information we compute is now written to disk. This gives
hooks full access to that data.

The format picked for that file uses a 2 characters prefix for the action:

    -R: tag removed
    +A: tag added
    -M: tag moved (old value)
    +M: tag moved (new value)

This format allows hooks to easily select the line that matters to them without
having to post process the file too much. Here is a couple of examples:

 * to select all newly tagged changeset, match "^+",
 * to detect tag move, match "^.M",
 * to detect tag deletion, match "-R".

Once again we rely on the fact the tag tests run through all possible
situations to test this change.

  $ hg init
  $ echo a > a
  $ hg add a
  $ hg commit -m test

Do we ever miss a sub-second change?:

  $ for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20; do
  >     hg co -qC 0
  >     echo b > a
  >     hg st
  > done
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a
  M a