tests/test-addremove-similar.t

revlog: addgroup checks if incoming deltas add censored revs, sets flag bit

A censored revision stored in a revlog should have the censored revlog index
flag bit set. This implies we must know if a revision is censored before we
add it to the revlog. When adding revisions from exchanged deltas, we would
prefer to determine this flag without decoding every single full text.

This change introduces a heuristic based on assumptions around the Mercurial
delta format and filelog metadata. Since deltas which produce a censored
revision must be full-replacement deltas, we can read the delta's first bytes
to check the filelog metadata. Since "censored" is the alphabetically first
filelog metadata key, censored filelog revisions have a well-known prefix we
can look for.

For more on the design and background of the censorship feature, see:
http://mercurial.selenic.com/wiki/CensorPlan

  $ hg init rep; cd rep

  $ touch empty-file
  $ $PYTHON -c 'for x in range(10000): print x' > large-file

  $ hg addremove
  adding empty-file
  adding large-file

  $ hg commit -m A

  $ rm large-file empty-file
  $ $PYTHON -c 'for x in range(10,10000): print x' > another-file

  $ hg addremove -s50
  adding another-file
  removing empty-file
  removing large-file
  recording removal of large-file as rename to another-file (99% similar)

  $ hg commit -m B

comparing two empty files caused ZeroDivisionError in the past

  $ hg update -C 0
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ rm empty-file
  $ touch another-empty-file
  $ hg addremove -s50
  adding another-empty-file
  removing empty-file

  $ cd ..

  $ hg init rep2; cd rep2

  $ $PYTHON -c 'for x in range(10000): print x' > large-file
  $ $PYTHON -c 'for x in range(50): print x' > tiny-file

  $ hg addremove
  adding large-file
  adding tiny-file

  $ hg commit -m A

  $ $PYTHON -c 'for x in range(70): print x' > small-file
  $ rm tiny-file
  $ rm large-file

  $ hg addremove -s50
  removing large-file
  adding small-file
  removing tiny-file
  recording removal of tiny-file as rename to small-file (82% similar)

  $ hg commit -m B

should all fail

  $ hg addremove -s foo
  abort: similarity must be a number
  [255]
  $ hg addremove -s -1
  abort: similarity must be between 0 and 100
  [255]
  $ hg addremove -s 1e6
  abort: similarity must be between 0 and 100
  [255]

  $ cd ..

Issue1527: repeated addremove causes util.Abort

  $ hg init rep3; cd rep3
  $ mkdir d
  $ echo a > d/a
  $ hg add d/a
  $ hg commit -m 1

  $ mv d/a d/b
  $ hg addremove -s80
  removing d/a
  adding d/b
  recording removal of d/a as rename to d/b (100% similar) (glob)
  $ hg debugstate
  r   0          0 1970-01-01 00:00:00 d/a
  a   0         -1 unset               d/b
  copy: d/a -> d/b
  $ mv d/b c

no copies found here (since the target isn't in d

  $ hg addremove -s80 d
  removing d/b (glob)

copies here

  $ hg addremove -s80
  adding c
  recording removal of d/a as rename to c (100% similar) (glob)

  $ cd ..