[PATCH 0/7] Make git log --graph looks better with -p and other diff options

When we run git log --graph with any other diff output function, such as '-p','--check','--numstat' or other diff optoins, the diff output area have no graph lines ahead of it. And this make the text graph looks strange.
The following 7 patches try to deal with this, and put the text graph columns before all the diff output lines.

Bo Yang (7):
  Add a prefix output callback to diff output.
  Change to call the new emit_line.
  Output the graph columns at the end of the commit message.
  diff.c: Output the text graph padding before each diff line.
  Emit a whole line once a time.
  Register a callback for graph output.
  Make --color-words work well with --graph.

 color.c    |   21 +++-
 color.h    |    3 +-
 diff.c     |  315 ++++++++++++++++++++++++++++++++++++++++++++----------------
 diff.h     |    5 +
 graph.c    |   22 ++++
 log-tree.c |    4 +
 6 files changed, 281 insertions(+), 89 deletions(-)