[RFC PATCH 0/3] Git integration update for DC-SHA1

Here are three patches to replace the last two patches from your series.

 - The Makefile knob is named DC_SHA1, not USE_SHA1DC; this is to
   keep it consistent with existing BLK_SHA1 and PPC_SHA1.

 - The CPP macro is called SHA1_DC, not SHA1_SHA1DC; again this is
   for consistency with SHA1_BLK and SHA1_PPC.

 - Switch the default from OpenSSL's implementation to DC_SHA1.
   Those who want OpenSSL's one can ask with OPENSSL_SHA1.

Jeff King (2):
  Makefile: add DC_SHA1 knob
  t0013: add a basic sha1 collision detection test

Junio C Hamano (1):
  Makefile: make DC_SHA1 the default

 Makefile                |  19 +++++++++++++++++--
 hash.h                  |   2 ++
 sha1dc/sha1.c           |  20 ++++++++++++++++++++
 sha1dc/sha1.h           |  15 +++++++++++++++
 t/t0013-sha1dc.sh       |  19 +++++++++++++++++++
 t/t0013/shattered-1.pdf | Bin 0 -> 422435 bytes
 6 files changed, 73 insertions(+), 2 deletions(-)
 create mode 100755 t/t0013-sha1dc.sh
 create mode 100644 t/t0013/shattered-1.pdf