combine-diff: move formatting logic to show_combined_diff()

This way, diff-files can make use of it.  Also implement the
full suite of what diff_flush_raw() supports just for
consistency.  With this, 'diff-tree -c -r --name-status' would
show what is expected.

There is no way to get the historical output (useful for
debugging and low-level Plumbing work) anymore, so tentatively
it makes '-m' to mean "do not combine and show individual diffs
with parents".

diff-files matches diff-tree to produce raw output for -c.  For
textual combined diff, use -p -c.

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/diff.h b/diff.h
index 9088519af..946a4067c 100644
--- a/diff.h
+++ b/diff.h
@@ -75,7 +75,8 @@ struct combine_diff_path {
 	 sizeof(struct combine_diff_parent) * (n) + (l) + 1)
 
 extern int show_combined_diff(struct combine_diff_path *elem, int num_parent,
-			      int dense, const char *header);
+			      int dense, const char *header,
+			      struct diff_options *);
 
 extern const char *diff_tree_combined_merge(const unsigned char *sha1, const char *, int, struct diff_options *opt);