[PATCH v2 0/4] extend smudge/clean filters with direct file access

Reroll of this patch set with changes:

* Renamed the new filter drivers for consistency with other configs.
* Improved documentation with feedback from Junio and others.
* Eliminated %p and instead append the filename to the commands
  (separated by a space).
* Fixed an FD leak and a space leak.
* Only use smudgeToFile with regular files, not symlinks.
* After running the smudgeToFile command, double-check that the
  expected file is present, in case the command was buggy and deleted it.
* Added a warning message when the new filter commands are configured
  but the old ones are not, so that the user knows it's refusing to use
  their configuration.

There's been good and helpful documentation and interface review, but some more code review would be good! Also, git-annex has a improved-smudge-filters branch now that demonstrates this interface.

Joey Hess (4):
  add smudgeToFile and cleanFromFile filter configs
  use cleanFromFile in git add
  use smudgeToFile in git checkout etc
  warn on unusable smudgeToFile/cleanFromFile config

 Documentation/config.txt        |  18 +++++-
 Documentation/gitattributes.txt |  37 ++++++++++++
 convert.c                       | 126 +++++++++++++++++++++++++++++++++++-----
 convert.h                       |  10 ++++
 entry.c                         |  37 +++++++++---
 sha1_file.c                     |  42 ++++++++++++--
 t/t0021-conversion.sh           |  64 ++++++++++++++++++++
 7 files changed, 304 insertions(+), 30 deletions(-)