merge-recursive --patience

Teach the merge-recursive strategy a --patience option to use the
"patience diff" algorithm, which tends to improve results when
cherry-picking a patch that reorders functions at the same time as
refactoring them.

To support this, struct merge_options and ll_merge_options gain an
xdl_opts member, so programs can use arbitrary xdiff flags (think
"XDF_IGNORE_WHITESPACE") in a git-aware merge.

git merge and git rebase can be passed the -Xpatience option to
use this.

[jn: split from --ignore-space patch; with documentation]

Signed-off-by: Justin Frankel <justin@cockos.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/ll-merge.h b/ll-merge.h
index 4b707f06c0..244a31f55a 100644
--- a/ll-merge.h
+++ b/ll-merge.h
@@ -9,6 +9,7 @@ struct ll_merge_options {
 	unsigned virtual_ancestor : 1;
 	unsigned variant : 2;	/* favor ours, favor theirs, or union merge */
 	unsigned renormalize : 1;
+	long xdl_opts;
 };
 
 int ll_merge(mmbuffer_t *result_buf,