view tests/test-diff-newlines.t @ 33087:fcd1c483f5ea

strip: add a delayedstrip method that works in a transaction

For long, the fact that strip does not work inside a transaction and some
code has to work with both obsstore and fallback to strip lead to duplicated
code like:

      with repo.transaction():
          ....
          if obsstore:
              obsstore.createmarkers(...)
      if not obsstore:
          repair.strip(...)

Things get more complex when you want to call something which may call strip
under the hood. Like you cannot simply write:

      with repo.transaction():
          ....
          rebasemod.rebase(...) # may call "strip", so this doesn't work

But you do want rebase to run inside a same transaction if possible, so the
code may look like:

      with repo.transaction():
          ....
          if obsstore:
              rebasemod.rebase(...)
              obsstore.createmarkers(...)
      if not obsstore:
          rebasemod.rebase(...)
          repair.strip(...)

That's ugly and error-prone. Ideally it's possible to just write:

      with repo.transaction():
          rebasemod.rebase(...)
          saferemovenodes(...)

This patch is the first step towards that. It adds a "delayedstrip" method
to repair.py which maintains a postclose callback in the transaction object.

  $ hg init

  $ $PYTHON -c 'file("a", "wb").write("confuse str.splitlines\nembedded\rnewline\n")'
  $ hg ci -Ama -d '1 0'
  adding a

  $ echo clean diff >> a
  $ hg ci -mb -d '2 0'

  $ hg diff -r0 -r1
  diff -r 107ba6f817b5 -r 310ce7989cdc a
  --- a/a	Thu Jan 01 00:00:01 1970 +0000
  +++ b/a	Thu Jan 01 00:00:02 1970 +0000
  @@ -1,2 +1,3 @@
   confuse str.splitlines
   embedded\r (no-eol) (esc)
  newline
  +clean diff