tests/test-execute-bit.t

convert: replace old sha1s in the description

This is a simple find-and-replace strategy for matching anything in the
old description of a converted commit and, if that matched sha1 exists
in the mapping, replacing it with the new sha1.

In particular, this is helpful for descriptions that contain tags with
messages such as, "Added tag 1.0 for commit abcde1234567" which will now
be automatically converted.

Tests have been updated accordingly.

  $ "$TESTDIR/hghave" execbit || exit 80

  $ hg init
  $ echo a > a
  $ hg ci -Am'not executable'
  adding a

  $ chmod +x a
  $ hg ci -m'executable'
  $ hg id
  79abf14474dc tip

Make sure we notice the change of mode if the cached size == -1:

  $ hg rm a
  $ hg revert -r 0 a
  $ hg debugstate
  n   0         -1 unset               a
  $ hg status
  M a

  $ hg up 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg id
  d69afc33ff8a
  $ test -x a && echo executable -- bad || echo not executable -- good
  not executable -- good