From cd1d61c44fb5c3d1c8e4c19becb66d90bbb9c676 Mon Sep 17 00:00:00 2001
From: Bert Wesarg <bert.wesarg@googlemail.com>
Date: Mon, 1 Mar 2010 22:46:25 +0100
Subject: [PATCH] make union merge an xdl merge favor

The current union merge driver is implemented as an post process.  But the
xdl_merge code is quite capable to produce the result by itself.  Therefore
move it there.

Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 ll-merge.c     | 43 +++++--------------------------------------
 xdiff/xdiff.h  |  1 +
 xdiff/xmerge.c | 20 +++++++++++++-------
 3 files changed, 19 insertions(+), 45 deletions(-)

diff --git a/ll-merge.c b/ll-merge.c
index 4c7f11ba8..a4b2f4c96 100644
--- a/ll-merge.c
+++ b/ll-merge.c
@@ -98,44 +98,11 @@ static int ll_union_merge(const struct ll_merge_driver *drv_unused,
 			  mmfile_t *src2, const char *name2,
 			  int flag, int marker_size)
 {
-	char *src, *dst;
-	long size;
-	int status, saved_style;
-
-	/* We have to force the RCS "merge" style */
-	saved_style = git_xmerge_style;
-	git_xmerge_style = 0;
-	status = ll_xdl_merge(drv_unused, result, path_unused,
-			      orig, src1, NULL, src2, NULL,
-			      flag, marker_size);
-	git_xmerge_style = saved_style;
-	if (status <= 0)
-		return status;
-	size = result->size;
-	src = dst = result->ptr;
-	while (size) {
-		char ch;
-		if ((marker_size < size) &&
-		    (*src == '<' || *src == '=' || *src == '>')) {
-			int i;
-			ch = *src;
-			for (i = 0; i < marker_size; i++)
-				if (src[i] != ch)
-					goto not_a_marker;
-			if (src[marker_size] != '\n')
-				goto not_a_marker;
-			src += marker_size + 1;
-			size -= marker_size + 1;
-			continue;
-		}
-	not_a_marker:
-		do {
-			ch = *src++;
-			*dst++ = ch;
-			size--;
-		} while (ch != '\n' && size);
-	}
-	result->size = dst - result->ptr;
+	/* Use union favor */
+	flag = (flag & 1) | (XDL_MERGE_FAVOR_UNION << 1);
+	return ll_xdl_merge(drv_unused, result, path_unused,
+			    orig, src1, NULL, src2, NULL,
+			    flag, marker_size);
 	return 0;
 }
 
diff --git a/xdiff/xdiff.h b/xdiff/xdiff.h
index 3f6229edb..22614d56e 100644
--- a/xdiff/xdiff.h
+++ b/xdiff/xdiff.h
@@ -61,6 +61,7 @@ extern "C" {
 /* merge favor modes */
 #define XDL_MERGE_FAVOR_OURS 1
 #define XDL_MERGE_FAVOR_THEIRS 2
+#define XDL_MERGE_FAVOR_UNION 3
 #define XDL_MERGE_FAVOR(flags) (((flags)>>4) & 3)
 #define XDL_MERGE_FLAGS(level, style, favor) ((level)|(style)|((favor)<<4))
 
diff --git a/xdiff/xmerge.c b/xdiff/xmerge.c
index 8cbe45e67..c901ecb99 100644
--- a/xdiff/xmerge.c
+++ b/xdiff/xmerge.c
@@ -28,6 +28,7 @@ typedef struct s_xdmerge {
 	 * 0 = conflict,
 	 * 1 = no conflict, take first,
 	 * 2 = no conflict, take second.
+	 * 3 = no conflict, take both.
 	 */
 	int mode;
 	/*
@@ -230,14 +231,19 @@ static int xdl_fill_merge_buffer(xdfenv_t *xe1, const char *name1,
 			size = fill_conflict_hunk(xe1, name1, xe2, name2,
 						  size, i, style, m, dest,
 						  marker_size);
-		else if (m->mode == 1)
-			size += xdl_recs_copy(xe1, i, m->i1 + m->chg1 - i, 0,
+		else if (m->mode & 3) {
+			/* Before conflicting part */
+			size += xdl_recs_copy(xe1, i, m->i1 - i, 0,
 					      dest ? dest + size : NULL);
-		else if (m->mode == 2)
-			size += xdl_recs_copy(xe2, m->i2 - m->i1 + i,
-					      m->i1 + m->chg2 - i, 0,
-					      dest ? dest + size : NULL);
-		else
+			/* Postimage from side #1 */
+			if (m->mode & 1)
+				size += xdl_recs_copy(xe1, m->i1, m->chg1, 1,
+						      dest ? dest + size : NULL);
+			/* Postimage from side #2 */
+			if (m->mode & 2)
+				size += xdl_recs_copy(xe2, m->i2, m->chg2, 1,
+						      dest ? dest + size : NULL);
+		} else
 			continue;
 		i = m->i1 + m->chg1;
 	}
-- 
2.26.2