view tests/test-debugcommands.t @ 18136:f23dea2b296e

copies: do not track backward copies, only renames (issue3739)

The inverse of a rename is a rename, but the inverse of a copy is not a copy.
Presenting it as such -- in particular, stuffing it into the same dict as real
copies -- causes bugs because other code starts believing the inverse copies
are real.

The only test whose output changes is test-mv-cp-st-diff.t. When a backwards
status -C command is run where a copy is involved, the inverse copy (which was
hitherto presented as a real copy) is no longer displayed.

Keeping track of inverse copies is useful in some situations -- composability
of diffs, for example, since adding "a" followed by an inverse copy "b" to "a"
is equivalent to a rename "b" to "a". However, representing them would require
a more complex data structure than the same dict in which real copies are also
stored.

  $ hg init debugrevlog
  $ cd debugrevlog
  $ echo a > a
  $ hg ci -Am adda
  adding a
  $ hg debugrevlog -m
  format : 1
  flags  : inline
  
  revisions     :  1
      merges    :  0 ( 0.00%)
      normal    :  1 (100.00%)
  revisions     :  1
      full      :  1 (100.00%)
      deltas    :  0 ( 0.00%)
  revision size : 44
      full      : 44 (100.00%)
      deltas    :  0 ( 0.00%)
  
  avg chain length  : 0
  compression ratio : 0
  
  uncompressed data size (min/max/avg) : 43 / 43 / 43
  full revision size (min/max/avg)     : 44 / 44 / 44
  delta size (min/max/avg)             : 0 / 0 / 0