X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=xdiff%2Fxmerge.c;h=b83b3348cc3aab66b13cb565a0a0fabaef4b689b;hb=761e8566cb072047e836f1d7f50d3c0f67d7eb00;hp=1fe7a1b060324f1382c924ba961d983b61d49c02;hpb=710daa83fc76f79b8f2ee9a765d297187c2c1aeb;p=git.git

diff --git a/xdiff/xmerge.c b/xdiff/xmerge.c
index 1fe7a1b06..b83b3348c 100644
--- a/xdiff/xmerge.c
+++ b/xdiff/xmerge.c
@@ -38,8 +38,9 @@ static int xdl_append_merge(xdmerge_t **merge, int mode,
 		long i1, long chg1, long i2, long chg2)
 {
 	xdmerge_t *m = *merge;
-	if (m && mode == m->mode &&
-			(i1 == m->i1 + m->chg1 || i2 == m->i2 + m->chg2)) {
+	if (m && (i1 <= m->i1 + m->chg1 || i2 <= m->i2 + m->chg2)) {
+		if (mode != m->mode)
+			m->mode = 0;
 		m->chg1 = i1 + chg1 - m->i1;
 		m->chg2 = i2 + chg2 - m->i2;
 	} else {
@@ -165,6 +166,8 @@ static int xdl_fill_merge_buffer(xdfenv_t *xe1, const char *name1,
 			size += xdl_recs_copy(xe2, m->i2 - m->i1 + i1,
 					m->i1 + m->chg2 - i1, 0,
 					dest ? dest + size : NULL);
+		else
+			continue;
 		i1 = m->i1 + m->chg1;
 	}
 	size += xdl_recs_copy(xe1, i1, xe1->xdf2.nrec - i1, 0,
@@ -189,6 +192,10 @@ static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
 		if (m->mode)
 			continue;
 
+		/* no sense refining a conflict when one side is empty */
+		if (m->chg1 == 0 || m->chg2 == 0)
+			continue;
+
 		/*
 		 * This probably does not work outside git, since
 		 * we have a very simple mmfile structure.
@@ -208,9 +215,10 @@ static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
 			return -1;
 		}
 		if (!xscr) {
-			/* If this happens, it's a bug. */
+			/* If this happens, the changes are identical. */
 			xdl_free_env(&xe);
-			return -2;
+			m->mode = 4;
+			continue;
 		}
 		x = xscr;
 		m->i1 = xscr->i1 + i1;
@@ -313,22 +321,10 @@ static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1,
 		i1 = xscr1->i1 + xscr1->chg1;
 		i2 = xscr2->i1 + xscr2->chg1;
 
-		if (i1 > i2) {
-			xscr1->chg1 -= i1 - i2;
-			xscr1->i1 = i2;
-			xscr1->i2 += xscr1->chg2;
-			xscr1->chg2 = 0;
+		if (i1 >= i2)
 			xscr2 = xscr2->next;
-		} else if (i2 > i1) {
-			xscr2->chg1 -= i2 - i1;
-			xscr2->i1 = i1;
-			xscr2->i2 += xscr2->chg2;
-			xscr2->chg2 = 0;
+		if (i2 >= i1)
 			xscr1 = xscr1->next;
-		} else {
-			xscr1 = xscr1->next;
-			xscr2 = xscr2->next;
-		}
 	}
 	while (xscr1) {
 		if (!changes)