X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=xdiff%2Fxmerge.c;h=b83b3348cc3aab66b13cb565a0a0fabaef4b689b;hb=ab002e34e26c39a716dc80359450f739ba907122;hp=7b85aa59062e5f6e617f62ef1003c4f9dd13de18;hpb=857b933e04bc21ce02043c3107c148f8dcbb4a01;p=git.git

diff --git a/xdiff/xmerge.c b/xdiff/xmerge.c
index 7b85aa590..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,
@@ -189,16 +192,20 @@ 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.
 		 */
 		t1.ptr = (char *)xe1->xdf2.recs[m->i1]->ptr;
-		t1.size = xe1->xdf2.recs[m->i1 + m->chg1]->ptr
-			+ xe1->xdf2.recs[m->i1 + m->chg1]->size - t1.ptr;
-		t2.ptr = (char *)xe2->xdf2.recs[m->i1]->ptr;
-		t2.size = xe2->xdf2.recs[m->i1 + m->chg1]->ptr
-			+ xe2->xdf2.recs[m->i1 + m->chg1]->size - t2.ptr;
+		t1.size = xe1->xdf2.recs[m->i1 + m->chg1 - 1]->ptr
+			+ xe1->xdf2.recs[m->i1 + m->chg1 - 1]->size - t1.ptr;
+		t2.ptr = (char *)xe2->xdf2.recs[m->i2]->ptr;
+		t2.size = xe2->xdf2.recs[m->i2 + m->chg2 - 1]->ptr
+			+ xe2->xdf2.recs[m->i2 + m->chg2 - 1]->size - t2.ptr;
 		if (xdl_do_diff(&t1, &t2, xpp, &xe) < 0)
 			return -1;
 		if (xdl_change_compact(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
@@ -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;
-			xscr1 = xscr1->next;
-		} else if (i2 > i1) {
-			xscr2->chg1 -= i2 - i1;
-			xscr2->i1 = i1;
-			xscr2->i2 += xscr2->chg2;
-			xscr2->chg2 = 0;
+		if (i1 >= i2)
 			xscr2 = xscr2->next;
-		} else {
+		if (i2 >= i1)
 			xscr1 = xscr1->next;
-			xscr2 = xscr2->next;
-		}
 	}
 	while (xscr1) {
 		if (!changes)
@@ -384,6 +380,7 @@ int xdl_merge(mmfile_t *orig, mmfile_t *mf1, const char *name1,
 		xpparam_t const *xpp, int level, mmbuffer_t *result) {
 	xdchange_t *xscr1, *xscr2;
 	xdfenv_t xe1, xe2;
+	int status;
 
 	result->ptr = NULL;
 	result->size = 0;
@@ -404,6 +401,7 @@ int xdl_merge(mmfile_t *orig, mmfile_t *mf1, const char *name1,
 		xdl_free_env(&xe2);
 		return -1;
 	}
+	status = 0;
 	if (xscr1 || xscr2) {
 		if (!xscr1) {
 			result->ptr = xdl_malloc(mf2->size);
@@ -413,14 +411,10 @@ int xdl_merge(mmfile_t *orig, mmfile_t *mf1, const char *name1,
 			result->ptr = xdl_malloc(mf1->size);
 			memcpy(result->ptr, mf1->ptr, mf1->size);
 			result->size = mf1->size;
-		} else if (xdl_do_merge(&xe1, xscr1, name1,
-					&xe2, xscr2, name2,
-					level, xpp, result) < 0) {
-			xdl_free_script(xscr1);
-			xdl_free_script(xscr2);
-			xdl_free_env(&xe1);
-			xdl_free_env(&xe2);
-			return -1;
+		} else {
+			status = xdl_do_merge(&xe1, xscr1, name1,
+					      &xe2, xscr2, name2,
+					      level, xpp, result);
 		}
 		xdl_free_script(xscr1);
 		xdl_free_script(xscr2);
@@ -428,6 +422,5 @@ int xdl_merge(mmfile_t *orig, mmfile_t *mf1, const char *name1,
 	xdl_free_env(&xe1);
 	xdl_free_env(&xe2);
 
-	return 0;
+	return status;
 }
-