1 files changed, 377 insertions, 168 deletions

diff --git a/diffcore-rename.c b/diffcore-rename.c
index 91fa2bea51..af1fe08861 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -4,6 +4,8 @@
 #include "cache.h"
 #include "diff.h"
 #include "diffcore.h"
+#include "hashmap.h"
+#include "progress.h"
 
 /* Table of rename/copy destinations */
 
@@ -13,8 +15,7 @@ static struct diff_rename_dst {
 } *rename_dst;
 static int rename_dst_nr, rename_dst_alloc;
 
-static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two,
-						 int insert_ok)
+static int find_rename_dst(struct diff_filespec *two)
 {
 	int first, last;
 
@@ -25,52 +26,64 @@ static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two,
 		struct diff_rename_dst *dst = &(rename_dst[next]);
 		int cmp = strcmp(two->path, dst->two->path);
 		if (!cmp)
-			return dst;
+			return next;
 		if (cmp < 0) {
 			last = next;
 			continue;
 		}
 		first = next+1;
 	}
-	/* not found */
-	if (!insert_ok)
-		return NULL;
+	return -first - 1;
+}
+
+static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two)
+{
+	int ofs = find_rename_dst(two);
+	return ofs < 0 ? NULL : &rename_dst[ofs];
+}
+
+/*
+ * Returns 0 on success, -1 if we found a duplicate.
+ */
+static int add_rename_dst(struct diff_filespec *two)
+{
+	int first = find_rename_dst(two);
+
+	if (first >= 0)
+		return -1;
+	first = -first - 1;
+
 	/* insert to make it at "first" */
-	if (rename_dst_alloc <= rename_dst_nr) {
-		rename_dst_alloc = alloc_nr(rename_dst_alloc);
-		rename_dst = xrealloc(rename_dst,
-				      rename_dst_alloc * sizeof(*rename_dst));
-	}
+	ALLOC_GROW(rename_dst, rename_dst_nr + 1, rename_dst_alloc);
 	rename_dst_nr++;
 	if (first < rename_dst_nr)
 		memmove(rename_dst + first + 1, rename_dst + first,
 			(rename_dst_nr - first - 1) * sizeof(*rename_dst));
 	rename_dst[first].two = alloc_filespec(two->path);
-	fill_filespec(rename_dst[first].two, two->sha1, two->mode);
+	fill_filespec(rename_dst[first].two, two->sha1, two->sha1_valid, two->mode);
 	rename_dst[first].pair = NULL;
-	return &(rename_dst[first]);
+	return 0;
 }
 
 /* Table of rename/copy src files */
 static struct diff_rename_src {
-	struct diff_filespec *one;
+	struct diff_filepair *p;
 	unsigned short score; /* to remember the break score */
-	unsigned src_path_left : 1;
 } *rename_src;
 static int rename_src_nr, rename_src_alloc;
 
-static struct diff_rename_src *register_rename_src(struct diff_filespec *one,
-						   int src_path_left,
-						   unsigned short score)
+static struct diff_rename_src *register_rename_src(struct diff_filepair *p)
 {
 	int first, last;
+	struct diff_filespec *one = p->one;
+	unsigned short score = p->score;
 
 	first = 0;
 	last = rename_src_nr;
 	while (last > first) {
 		int next = (last + first) >> 1;
 		struct diff_rename_src *src = &(rename_src[next]);
-		int cmp = strcmp(one->path, src->one->path);
+		int cmp = strcmp(one->path, src->p->one->path);
 		if (!cmp)
 			return src;
 		if (cmp < 0) {
@@ -81,48 +94,36 @@ static struct diff_rename_src *register_rename_src(struct diff_filespec *one,
 	}
 
 	/* insert to make it at "first" */
-	if (rename_src_alloc <= rename_src_nr) {
-		rename_src_alloc = alloc_nr(rename_src_alloc);
-		rename_src = xrealloc(rename_src,
-				      rename_src_alloc * sizeof(*rename_src));
-	}
+	ALLOC_GROW(rename_src, rename_src_nr + 1, rename_src_alloc);
 	rename_src_nr++;
 	if (first < rename_src_nr)
 		memmove(rename_src + first + 1, rename_src + first,
 			(rename_src_nr - first - 1) * sizeof(*rename_src));
-	rename_src[first].one = one;
+	rename_src[first].p = p;
 	rename_src[first].score = score;
-	rename_src[first].src_path_left = src_path_left;
 	return &(rename_src[first]);
 }
 
-static int is_exact_match(struct diff_filespec *src,
-			  struct diff_filespec *dst,
-			  int contents_too)
+static int basename_same(struct diff_filespec *src, struct diff_filespec *dst)
 {
-	if (src->sha1_valid && dst->sha1_valid &&
-	    !hashcmp(src->sha1, dst->sha1))
-		return 1;
-	if (!contents_too)
-		return 0;
-	if (diff_populate_filespec(src, 1) || diff_populate_filespec(dst, 1))
-		return 0;
-	if (src->size != dst->size)
-		return 0;
-	if (src->sha1_valid && dst->sha1_valid)
-	    return !hashcmp(src->sha1, dst->sha1);
-	if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0))
-		return 0;
-	if (src->size == dst->size &&
-	    !memcmp(src->data, dst->data, src->size))
-		return 1;
-	return 0;
+	int src_len = strlen(src->path), dst_len = strlen(dst->path);
+	while (src_len && dst_len) {
+		char c1 = src->path[--src_len];
+		char c2 = dst->path[--dst_len];
+		if (c1 != c2)
+			return 0;
+		if (c1 == '/')
+			return 1;
+	}
+	return (!src_len || src->path[src_len - 1] == '/') &&
+		(!dst_len || dst->path[dst_len - 1] == '/');
 }
 
 struct diff_score {
 	int src; /* index in rename_src */
 	int dst; /* index in rename_dst */
-	int score;
+	unsigned short score;
+	short name_score;
 };
 
 static int estimate_similarity(struct diff_filespec *src,
@@ -153,6 +154,22 @@ static int estimate_similarity(struct diff_filespec *src,
 	if (!S_ISREG(src->mode) || !S_ISREG(dst->mode))
 		return 0;
 
+	/*
+	 * Need to check that source and destination sizes are
+	 * filled in before comparing them.
+	 *
+	 * If we already have "cnt_data" filled in, we know it's
+	 * all good (avoid checking the size for zero, as that
+	 * is a possible size - we really should have a flag to
+	 * say whether the size is valid or not!)
+	 */
+	if (!src->cnt_data &&
+	    diff_populate_filespec(src, CHECK_SIZE_ONLY))
+		return 0;
+	if (!dst->cnt_data &&
+	    diff_populate_filespec(dst, CHECK_SIZE_ONLY))
+		return 0;
+
 	max_size = ((src->size > dst->size) ? src->size : dst->size);
 	base_size = ((src->size < dst->size) ? src->size : dst->size);
 	delta_size = max_size - base_size;
@@ -165,16 +182,17 @@ static int estimate_similarity(struct diff_filespec *src,
 	 * and the final score computation below would not have a
 	 * divide-by-zero issue.
 	 */
-	if (base_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
+	if (max_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
 		return 0;
 
-	if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0))
-		return 0; /* error but caught downstream */
-
+	if (!src->cnt_data && diff_populate_filespec(src, 0))
+		return 0;
+	if (!dst->cnt_data && diff_populate_filespec(dst, 0))
+		return 0;
 
-	delta_limit = base_size * (MAX_SCORE-minimum_score) / MAX_SCORE;
-	if (diffcore_count_changes(src->data, src->size,
-				   dst->data, dst->size,
+	delta_limit = (unsigned long)
+		(base_size * (MAX_SCORE-minimum_score) / MAX_SCORE);
+	if (diffcore_count_changes(src, dst,
 				   &src->cnt_data, &dst->cnt_data,
 				   delta_limit,
 				   &src_copied, &literal_added))
@@ -186,33 +204,31 @@ static int estimate_similarity(struct diff_filespec *src,
 	if (!dst->size)
 		score = 0; /* should not happen */
 	else
-		score = src_copied * MAX_SCORE / max_size;
+		score = (int)(src_copied * MAX_SCORE / max_size);
 	return score;
 }
 
 static void record_rename_pair(int dst_index, int src_index, int score)
 {
-	struct diff_filespec *one, *two, *src, *dst;
+	struct diff_filespec *src, *dst;
 	struct diff_filepair *dp;
 
 	if (rename_dst[dst_index].pair)
 		die("internal error: dst already matched.");
 
-	src = rename_src[src_index].one;
-	one = alloc_filespec(src->path);
-	fill_filespec(one, src->sha1, src->mode);
+	src = rename_src[src_index].p->one;
+	src->rename_used++;
+	src->count++;
 
 	dst = rename_dst[dst_index].two;
-	two = alloc_filespec(dst->path);
-	fill_filespec(two, dst->sha1, dst->mode);
+	dst->count++;
 
-	dp = diff_queue(NULL, one, two);
+	dp = diff_queue(NULL, src, dst);
 	dp->renamed_pair = 1;
 	if (!strcmp(src->path, dst->path))
 		dp->score = rename_src[src_index].score;
 	else
 		dp->score = score;
-	dp->source_stays = rename_src[src_index].src_path_left;
 	rename_dst[dst_index].pair = dp;
 }
 
@@ -223,38 +239,221 @@ static void record_rename_pair(int dst_index, int src_index, int score)
 static int score_compare(const void *a_, const void *b_)
 {
 	const struct diff_score *a = a_, *b = b_;
+
+	/* sink the unused ones to the bottom */
+	if (a->dst < 0)
+		return (0 <= b->dst);
+	else if (b->dst < 0)
+		return -1;
+
+	if (a->score == b->score)
+		return b->name_score - a->name_score;
+
 	return b->score - a->score;
 }
 
-static int compute_stays(struct diff_queue_struct *q,
-			 struct diff_filespec *one)
+struct file_similarity {
+	struct hashmap_entry entry;
+	int index;
+	struct diff_filespec *filespec;
+};
+
+static unsigned int hash_filespec(struct diff_filespec *filespec)
 {
-	int i;
-	for (i = 0; i < q->nr; i++) {
-		struct diff_filepair *p = q->queue[i];
-		if (strcmp(one->path, p->two->path))
+	if (!filespec->sha1_valid) {
+		if (diff_populate_filespec(filespec, 0))
+			return 0;
+		hash_sha1_file(filespec->data, filespec->size, "blob", filespec->sha1);
+	}
+	return sha1hash(filespec->sha1);
+}
+
+static int find_identical_files(struct hashmap *srcs,
+				int dst_index,
+				struct diff_options *options)
+{
+	int renames = 0;
+
+	struct diff_filespec *target = rename_dst[dst_index].two;
+	struct file_similarity *p, *best = NULL;
+	int i = 100, best_score = -1;
+
+	/*
+	 * Find the best source match for specified destination.
+	 */
+	p = hashmap_get_from_hash(srcs, hash_filespec(target), NULL);
+	for (; p; p = hashmap_get_next(srcs, p)) {
+		int score;
+		struct diff_filespec *source = p->filespec;
+
+		/* False hash collision? */
+		if (hashcmp(source->sha1, target->sha1))
+			continue;
+		/* Non-regular files? If so, the modes must match! */
+		if (!S_ISREG(source->mode) || !S_ISREG(target->mode)) {
+			if (source->mode != target->mode)
+				continue;
+		}
+		/* Give higher scores to sources that haven't been used already */
+		score = !source->rename_used;
+		if (source->rename_used && options->detect_rename != DIFF_DETECT_COPY)
 			continue;
-		if (DIFF_PAIR_RENAME(p)) {
-			return 0; /* something else is renamed into this */
+		score += basename_same(source, target);
+		if (score > best_score) {
+			best = p;
+			best_score = score;
+			if (score == 2)
+				break;
 		}
+
+		/* Too many identical alternatives? Pick one */
+		if (!--i)
+			break;
+	}
+	if (best) {
+		record_rename_pair(dst_index, best->index, MAX_SCORE);
+		renames++;
+	}
+	return renames;
+}
+
+static void insert_file_table(struct hashmap *table, int index, struct diff_filespec *filespec)
+{
+	struct file_similarity *entry = xmalloc(sizeof(*entry));
+
+	entry->index = index;
+	entry->filespec = filespec;
+
+	hashmap_entry_init(entry, hash_filespec(filespec));
+	hashmap_add(table, entry);
+}
+
+/*
+ * Find exact renames first.
+ *
+ * The first round matches up the up-to-date entries,
+ * and then during the second round we try to match
+ * cache-dirty entries as well.
+ */
+static int find_exact_renames(struct diff_options *options)
+{
+	int i, renames = 0;
+	struct hashmap file_table;
+
+	/* Add all sources to the hash table */
+	hashmap_init(&file_table, NULL, rename_src_nr);
+	for (i = 0; i < rename_src_nr; i++)
+		insert_file_table(&file_table, i, rename_src[i].p->one);
+
+	/* Walk the destinations and find best source match */
+	for (i = 0; i < rename_dst_nr; i++)
+		renames += find_identical_files(&file_table, i, options);
+
+	/* Free the hash data structure and entries */
+	hashmap_free(&file_table, 1);
+
+	return renames;
+}
+
+#define NUM_CANDIDATE_PER_DST 4
+static void record_if_better(struct diff_score m[], struct diff_score *o)
+{
+	int i, worst;
+
+	/* find the worst one */
+	worst = 0;
+	for (i = 1; i < NUM_CANDIDATE_PER_DST; i++)
+		if (score_compare(&m[i], &m[worst]) > 0)
+			worst = i;
+
+	/* is it better than the worst one? */
+	if (score_compare(&m[worst], o) > 0)
+		m[worst] = *o;
+}
+
+/*
+ * Returns:
+ * 0 if we are under the limit;
+ * 1 if we need to disable inexact rename detection;
+ * 2 if we would be under the limit if we were given -C instead of -C -C.
+ */
+static int too_many_rename_candidates(int num_create,
+				      struct diff_options *options)
+{
+	int rename_limit = options->rename_limit;
+	int num_src = rename_src_nr;
+	int i;
+
+	options->needed_rename_limit = 0;
+
+	/*
+	 * This basically does a test for the rename matrix not
+	 * growing larger than a "rename_limit" square matrix, ie:
+	 *
+	 *    num_create * num_src > rename_limit * rename_limit
+	 *
+	 * but handles the potential overflow case specially (and we
+	 * assume at least 32-bit integers)
+	 */
+	if (rename_limit <= 0 || rename_limit > 32767)
+		rename_limit = 32767;
+	if ((num_create <= rename_limit || num_src <= rename_limit) &&
+	    (num_create * num_src <= rename_limit * rename_limit))
+		return 0;
+
+	options->needed_rename_limit =
+		num_src > num_create ? num_src : num_create;
+
+	/* Are we running under -C -C? */
+	if (!DIFF_OPT_TST(options, FIND_COPIES_HARDER))
+		return 1;
+
+	/* Would we bust the limit if we were running under -C? */
+	for (num_src = i = 0; i < rename_src_nr; i++) {
+		if (diff_unmodified_pair(rename_src[i].p))
+			continue;
+		num_src++;
 	}
+	if ((num_create <= rename_limit || num_src <= rename_limit) &&
+	    (num_create * num_src <= rename_limit * rename_limit))
+		return 2;
 	return 1;
 }
 
+static int find_renames(struct diff_score *mx, int dst_cnt, int minimum_score, int copies)
+{
+	int count = 0, i;
+
+	for (i = 0; i < dst_cnt * NUM_CANDIDATE_PER_DST; i++) {
+		struct diff_rename_dst *dst;
+
+		if ((mx[i].dst < 0) ||
+		    (mx[i].score < minimum_score))
+			break; /* there is no more usable pair. */
+		dst = &rename_dst[mx[i].dst];
+		if (dst->pair)
+			continue; /* already done, either exact or fuzzy. */
+		if (!copies && rename_src[mx[i].src].p->one->rename_used)
+			continue;
+		record_rename_pair(mx[i].dst, mx[i].src, mx[i].score);
+		count++;
+	}
+	return count;
+}
+
 void diffcore_rename(struct diff_options *options)
 {
 	int detect_rename = options->detect_rename;
 	int minimum_score = options->rename_score;
-	int rename_limit = options->rename_limit;
 	struct diff_queue_struct *q = &diff_queued_diff;
 	struct diff_queue_struct outq;
 	struct diff_score *mx;
-	int i, j, rename_count, contents_too;
-	int num_create, num_src, dst_cnt;
+	int i, j, rename_count, skip_unmodified = 0;
+	int num_create, dst_cnt;
+	struct progress *progress = NULL;
 
 	if (!minimum_score)
 		minimum_score = DEFAULT_RENAME_SCORE;
-	rename_count = 0;
 
 	for (i = 0; i < q->nr; i++) {
 		struct diff_filepair *p = q->queue[i];
@@ -264,107 +463,146 @@ void diffcore_rename(struct diff_options *options)
 			else if (options->single_follow &&
 				 strcmp(options->single_follow, p->two->path))
 				continue; /* not interested */
-			else
-				locate_rename_dst(p->two, 1);
+			else if (!DIFF_OPT_TST(options, RENAME_EMPTY) &&
+				 is_empty_blob_sha1(p->two->sha1))
+				continue;
+			else if (add_rename_dst(p->two) < 0) {
+				warning("skipping rename detection, detected"
+					" duplicate destination '%s'",
+					p->two->path);
+				goto cleanup;
+			}
 		}
-		else if (!DIFF_FILE_VALID(p->two)) {
-			/* If the source is a broken "delete", and
+		else if (!DIFF_OPT_TST(options, RENAME_EMPTY) &&
+			 is_empty_blob_sha1(p->one->sha1))
+			continue;
+		else if (!DIFF_PAIR_UNMERGED(p) && !DIFF_FILE_VALID(p->two)) {
+			/*
+			 * If the source is a broken "delete", and
 			 * they did not really want to get broken,
 			 * that means the source actually stays.
+			 * So we increment the "rename_used" score
+			 * by one, to indicate ourselves as a user
+			 */
+			if (p->broken_pair && !p->score)
+				p->one->rename_used++;
+			register_rename_src(p);
+		}
+		else if (detect_rename == DIFF_DETECT_COPY) {
+			/*
+			 * Increment the "rename_used" score by
+			 * one, to indicate ourselves as a user.
 			 */
-			int stays = (p->broken_pair && !p->score);
-			register_rename_src(p->one, stays, p->score);
+			p->one->rename_used++;
+			register_rename_src(p);
 		}
-		else if (detect_rename == DIFF_DETECT_COPY)
-			register_rename_src(p->one, 1, p->score);
 	}
-	if (rename_dst_nr == 0 || rename_src_nr == 0 ||
-	    (0 < rename_limit && rename_limit < rename_dst_nr))
+	if (rename_dst_nr == 0 || rename_src_nr == 0)
 		goto cleanup; /* nothing to do */
 
-	/* We really want to cull the candidates list early
+	/*
+	 * We really want to cull the candidates list early
 	 * with cheap tests in order to avoid doing deltas.
-	 * The first round matches up the up-to-date entries,
-	 * and then during the second round we try to match
-	 * cache-dirty entries as well.
 	 */
-	for (contents_too = 0; contents_too < 2; contents_too++) {
-		for (i = 0; i < rename_dst_nr; i++) {
-			struct diff_filespec *two = rename_dst[i].two;
-			if (rename_dst[i].pair)
-				continue; /* dealt with an earlier round */
-			for (j = 0; j < rename_src_nr; j++) {
-				struct diff_filespec *one = rename_src[j].one;
-				if (!is_exact_match(one, two, contents_too))
-					continue;
-				record_rename_pair(i, j, MAX_SCORE);
-				rename_count++;
-				break; /* we are done with this entry */
-			}
-		}
-	}
+	rename_count = find_exact_renames(options);
 
-	/* Have we run out the created file pool?  If so we can avoid
-	 * doing the delta matrix altogether.
+	/* Did we only want exact renames? */
+	if (minimum_score == MAX_SCORE)
+		goto cleanup;
+
+	/*
+	 * Calculate how many renames are left (but all the source
+	 * files still remain as options for rename/copies!)
 	 */
-	if (rename_count == rename_dst_nr)
+	num_create = (rename_dst_nr - rename_count);
+
+	/* All done? */
+	if (!num_create)
 		goto cleanup;
 
-	if (minimum_score == MAX_SCORE)
+	switch (too_many_rename_candidates(num_create, options)) {
+	case 1:
 		goto cleanup;
+	case 2:
+		options->degraded_cc_to_c = 1;
+		skip_unmodified = 1;
+		break;
+	default:
+		break;
+	}
 
-	num_create = (rename_dst_nr - rename_count);
-	num_src = rename_src_nr;
-	mx = xmalloc(sizeof(*mx) * num_create * num_src);
+	if (options->show_rename_progress) {
+		progress = start_progress_delay(
+				_("Performing inexact rename detection"),
+				rename_dst_nr * rename_src_nr, 50, 1);
+	}
+
+	mx = xcalloc(num_create * NUM_CANDIDATE_PER_DST, sizeof(*mx));
 	for (dst_cnt = i = 0; i < rename_dst_nr; i++) {
-		int base = dst_cnt * num_src;
 		struct diff_filespec *two = rename_dst[i].two;
+		struct diff_score *m;
+
 		if (rename_dst[i].pair)
 			continue; /* dealt with exact match already. */
+
+		m = &mx[dst_cnt * NUM_CANDIDATE_PER_DST];
+		for (j = 0; j < NUM_CANDIDATE_PER_DST; j++)
+			m[j].dst = -1;
+
 		for (j = 0; j < rename_src_nr; j++) {
-			struct diff_filespec *one = rename_src[j].one;
-			struct diff_score *m = &mx[base+j];
-			m->src = j;
-			m->dst = i;
-			m->score = estimate_similarity(one, two,
-						       minimum_score);
+			struct diff_filespec *one = rename_src[j].p->one;
+			struct diff_score this_src;
+
+			if (skip_unmodified &&
+			    diff_unmodified_pair(rename_src[j].p))
+				continue;
+
+			this_src.score = estimate_similarity(one, two,
+							     minimum_score);
+			this_src.name_score = basename_same(one, two);
+			this_src.dst = i;
+			this_src.src = j;
+			record_if_better(m, &this_src);
+			/*
+			 * Once we run estimate_similarity,
+			 * We do not need the text anymore.
+			 */
+			diff_free_filespec_blob(one);
+			diff_free_filespec_blob(two);
 		}
-		/* We do not need the text anymore */
-		diff_free_filespec_data(two);
 		dst_cnt++;
+		display_progress(progress, (i+1)*rename_src_nr);
 	}
+	stop_progress(&progress);
+
 	/* cost matrix sorted by most to least similar pair */
-	qsort(mx, num_create * num_src, sizeof(*mx), score_compare);
-	for (i = 0; i < num_create * num_src; i++) {
-		struct diff_rename_dst *dst = &rename_dst[mx[i].dst];
-		if (dst->pair)
-			continue; /* already done, either exact or fuzzy. */
-		if (mx[i].score < minimum_score)
-			break; /* there is no more usable pair. */
-		record_rename_pair(mx[i].dst, mx[i].src, mx[i].score);
-		rename_count++;
-	}
+	qsort(mx, dst_cnt * NUM_CANDIDATE_PER_DST, sizeof(*mx), score_compare);
+
+	rename_count += find_renames(mx, dst_cnt, minimum_score, 0);
+	if (detect_rename == DIFF_DETECT_COPY)
+		rename_count += find_renames(mx, dst_cnt, minimum_score, 1);
 	free(mx);
 
  cleanup:
 	/* At this point, we have found some renames and copies and they
 	 * are recorded in rename_dst.  The original list is still in *q.
 	 */
-	outq.queue = NULL;
-	outq.nr = outq.alloc = 0;
+	DIFF_QUEUE_CLEAR(&outq);
 	for (i = 0; i < q->nr; i++) {
 		struct diff_filepair *p = q->queue[i];
 		struct diff_filepair *pair_to_free = NULL;
 
-		if (!DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
+		if (DIFF_PAIR_UNMERGED(p)) {
+			diff_q(&outq, p);
+		}
+		else if (!DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
 			/*
 			 * Creation
 			 *
 			 * We would output this create record if it has
 			 * not been turned into a rename/copy already.
 			 */
-			struct diff_rename_dst *dst =
-				locate_rename_dst(p->two, 0);
+			struct diff_rename_dst *dst = locate_rename_dst(p->two);
 			if (dst && dst->pair) {
 				diff_q(&outq, dst->pair);
 				pair_to_free = p;
@@ -394,23 +632,13 @@ void diffcore_rename(struct diff_options *options)
 			 */
 			if (DIFF_PAIR_BROKEN(p)) {
 				/* broken delete */
-				struct diff_rename_dst *dst =
-					locate_rename_dst(p->one, 0);
+				struct diff_rename_dst *dst = locate_rename_dst(p->one);
 				if (dst && dst->pair)
 					/* counterpart is now rename/copy */
 					pair_to_free = p;
 			}
 			else {
-				for (j = 0; j < rename_dst_nr; j++) {
-					if (!rename_dst[j].pair)
-						continue;
-					if (strcmp(rename_dst[j].pair->
-						   one->path,
-						   p->one->path))
-						continue;
-					break;
-				}
-				if (j < rename_dst_nr)
+				if (p->one->rename_used)
 					/* this path remains */
 					pair_to_free = p;
 			}
@@ -436,27 +664,8 @@ void diffcore_rename(struct diff_options *options)
 	*q = outq;
 	diff_debug_queue("done collapsing", q);
 
-	/* We need to see which rename source really stays here;
-	 * earlier we only checked if the path is left in the result,
-	 * but even if a path remains in the result, if that is coming
-	 * from copying something else on top of it, then the original
-	 * source is lost and does not stay.
-	 */
-	for (i = 0; i < q->nr; i++) {
-		struct diff_filepair *p = q->queue[i];
-		if (DIFF_PAIR_RENAME(p) && p->source_stays) {
-			/* If one appears as the target of a rename-copy,
-			 * then mark p->source_stays = 0; otherwise
-			 * leave it as is.
-			 */
-			p->source_stays = compute_stays(q, p->one);
-		}
-	}
-
-	for (i = 0; i < rename_dst_nr; i++) {
-		diff_free_filespec_data(rename_dst[i].two);
-		free(rename_dst[i].two);
-	}
+	for (i = 0; i < rename_dst_nr; i++)
+		free_filespec(rename_dst[i].two);
 
 	free(rename_dst);
 	rename_dst = NULL;