X-Git-Url: https://git.octo.it/?a=blobdiff_plain;ds=sidebyside;f=diff.c;h=a72029058e195c596ab958e26cc0176cb0dc6b1c;hb=46e63efc072bc440e4c6aad33d3157b70f5172b6;hp=ababcaa0e663254bf4d18adbb5fb0db3ac80f202;hpb=f7c1512af8ff4f821c530f9a4bc8f8ff25733d51;p=git.git

diff --git a/diff.c b/diff.c
index ababcaa0..a7202905 100644
--- a/diff.c
+++ b/diff.c
@@ -12,9 +12,7 @@ static const char *diff_opts = "-pu";
 static unsigned char null_sha1[20] = { 0, };
 
 static int reverse_diff;
-static int generate_patch;
-static int line_termination = '\n';
-static int inter_name_termination = '\t';
+static int use_size_cache;
 
 static const char *external_diff(void)
 {
@@ -85,10 +83,88 @@ static struct diff_tempfile {
 	char tmp_path[50];
 } diff_temp[2];
 
+static int count_lines(const char *filename)
+{
+	FILE *in;
+	int count, ch, completely_empty = 1, nl_just_seen = 0;
+	in = fopen(filename, "r");
+	count = 0;
+	while ((ch = fgetc(in)) != EOF)
+		if (ch == '\n') {
+			count++;
+			nl_just_seen = 1;
+			completely_empty = 0;
+		}
+		else {
+			nl_just_seen = 0;
+			completely_empty = 0;
+		}
+	fclose(in);
+	if (completely_empty)
+		return 0;
+	if (!nl_just_seen)
+		count++; /* no trailing newline */
+	return count;
+}
+
+static void print_line_count(int count)
+{
+	switch (count) {
+	case 0:
+		printf("0,0");
+		break;
+	case 1:
+		printf("1");
+		break;
+	default:
+		printf("1,%d", count);
+		break;
+	}
+}
+
+static void copy_file(int prefix, const char *filename)
+{
+	FILE *in;
+	int ch, nl_just_seen = 1;
+	in = fopen(filename, "r");
+	while ((ch = fgetc(in)) != EOF) {
+		if (nl_just_seen)
+			putchar(prefix);
+		putchar(ch);
+		if (ch == '\n')
+			nl_just_seen = 1;
+		else
+			nl_just_seen = 0;
+	}
+	fclose(in);
+	if (!nl_just_seen)
+		printf("\n\\ No newline at end of file\n");
+}
+
+static void emit_rewrite_diff(const char *name_a,
+			      const char *name_b,
+			      struct diff_tempfile *temp)
+{
+	/* Use temp[i].name as input, name_a and name_b as labels */
+	int lc_a, lc_b;
+	lc_a = count_lines(temp[0].name);
+	lc_b = count_lines(temp[1].name);
+	printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
+	print_line_count(lc_a);
+	printf(" +");
+	print_line_count(lc_b);
+	printf(" @@\n");
+	if (lc_a)
+		copy_file('-', temp[0].name);
+	if (lc_b)
+		copy_file('+', temp[1].name);
+}
+
 static void builtin_diff(const char *name_a,
 			 const char *name_b,
 			 struct diff_tempfile *temp,
-			 const char *xfrm_msg)
+			 const char *xfrm_msg,
+			 int complete_rewrite)
 {
 	int i, next_at, cmd_size;
 	const char *diff_cmd = "diff -L'%s%s' -L'%s%s'";
@@ -134,23 +210,33 @@ static void builtin_diff(const char *name_a,
 			    diff_arg, input_name_sq[0], input_name_sq[1]);
 
 	printf("diff --git a/%s b/%s\n", name_a, name_b);
-	if (!path1[0][0])
+	if (!path1[0][0]) {
 		printf("new file mode %s\n", temp[1].mode);
-	else if (!path1[1][0])
+		if (xfrm_msg && xfrm_msg[0])
+			puts(xfrm_msg);
+	}
+	else if (!path1[1][0]) {
 		printf("deleted file mode %s\n", temp[0].mode);
+		if (xfrm_msg && xfrm_msg[0])
+			puts(xfrm_msg);
+	}
 	else {
 		if (strcmp(temp[0].mode, temp[1].mode)) {
 			printf("old mode %s\n", temp[0].mode);
 			printf("new mode %s\n", temp[1].mode);
 		}
 		if (xfrm_msg && xfrm_msg[0])
-			fputs(xfrm_msg, stdout);
-
+			puts(xfrm_msg);
 		if (strncmp(temp[0].mode, temp[1].mode, 3))
 			/* we do not run diff between different kind
 			 * of objects.
 			 */
 			exit(0);
+		if (complete_rewrite) {
+			fflush(NULL);
+			emit_rewrite_diff(name_a, name_b, temp);
+			exit(0);
+		}
 	}
 	fflush(NULL);
 	execlp("/bin/sh","sh", "-c", cmd, NULL);
@@ -174,8 +260,8 @@ struct diff_filespec *alloc_filespec(const char *path)
 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 		   unsigned short mode)
 {
-	if (mode) { /* just playing defensive */
-		spec->mode = mode;
+	if (mode) {
+		spec->mode = DIFF_FILE_CANON_MODE(mode);
 		memcpy(spec->sha1, sha1, 20);
 		spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 	}
@@ -225,12 +311,61 @@ static int work_tree_matches(const char *name, const unsigned char *sha1)
 	return 1;
 }
 
+static struct sha1_size_cache {
+	unsigned char sha1[20];
+	unsigned long size;
+} **sha1_size_cache;
+static int sha1_size_cache_nr, sha1_size_cache_alloc;
+
+static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
+						 int find_only,
+						 unsigned long size)
+{
+	int first, last;
+	struct sha1_size_cache *e;
+
+	first = 0;
+	last = sha1_size_cache_nr;
+	while (last > first) {
+		int cmp, next = (last + first) >> 1;
+		e = sha1_size_cache[next];
+		cmp = memcmp(e->sha1, sha1, 20);
+		if (!cmp)
+			return e;
+		if (cmp < 0) {
+			last = next;
+			continue;
+		}
+		first = next+1;
+	}
+	/* not found */
+	if (find_only)
+		return NULL;
+	/* insert to make it at "first" */
+	if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
+		sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
+		sha1_size_cache = xrealloc(sha1_size_cache,
+					   sha1_size_cache_alloc *
+					   sizeof(*sha1_size_cache));
+	}
+	sha1_size_cache_nr++;
+	if (first < sha1_size_cache_nr)
+		memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
+			(sha1_size_cache_nr - first - 1) *
+			sizeof(*sha1_size_cache));
+	e = xmalloc(sizeof(struct sha1_size_cache));
+	sha1_size_cache[first] = e;
+	memcpy(e->sha1, sha1, 20);
+	e->size = size;
+	return e;
+}
+
 /*
  * While doing rename detection and pickaxe operation, we may need to
  * grab the data for the blob (or file) for our own in-core comparison.
  * diff_filespec has data and size fields for this purpose.
  */
-int diff_populate_filespec(struct diff_filespec *s)
+int diff_populate_filespec(struct diff_filespec *s, int size_only)
 {
 	int err = 0;
 	if (!DIFF_FILE_VALID(s))
@@ -238,6 +373,9 @@ int diff_populate_filespec(struct diff_filespec *s)
 	if (S_ISDIR(s->mode))
 		return -1;
 
+	if (!use_size_cache)
+		size_only = 0;
+
 	if (s->data)
 		return err;
 	if (!s->sha1_valid ||
@@ -257,6 +395,8 @@ int diff_populate_filespec(struct diff_filespec *s)
 		s->size = st.st_size;
 		if (!s->size)
 			goto empty;
+		if (size_only)
+			return 0;
 		if (S_ISLNK(st.st_mode)) {
 			int ret;
 			s->data = xmalloc(s->size);
@@ -277,8 +417,21 @@ int diff_populate_filespec(struct diff_filespec *s)
 	}
 	else {
 		char type[20];
-		s->data = read_sha1_file(s->sha1, type, &s->size);
-		s->should_free = 1;
+		struct sha1_size_cache *e;
+
+		if (size_only) {
+			e = locate_size_cache(s->sha1, 1, 0);
+			if (e) {
+				s->size = e->size;
+				return 0;
+			}
+			if (!sha1_object_info(s->sha1, type, &s->size))
+				locate_size_cache(s->sha1, 0, s->size);
+		}
+		else {
+			s->data = read_sha1_file(s->sha1, type, &s->size);
+			s->should_free = 1;
+		}
 	}
 	return 0;
 }
@@ -358,13 +511,18 @@ static void prepare_temp_file(const char *name,
 				strcpy(temp->hex, sha1_to_hex(null_sha1));
 			else
 				strcpy(temp->hex, sha1_to_hex(one->sha1));
-			sprintf(temp->mode, "%06o",
-				S_IFREG |ce_permissions(st.st_mode));
+			/* Even though we may sometimes borrow the
+			 * contents from the work tree, we always want
+			 * one->mode.  mode is trustworthy even when
+			 * !(one->sha1_valid), as long as
+			 * DIFF_FILE_VALID(one).
+			 */
+			sprintf(temp->mode, "%06o", one->mode);
 		}
 		return;
 	}
 	else {
-		if (diff_populate_filespec(one))
+		if (diff_populate_filespec(one, 0))
 			die("cannot read data blob for %s", one->path);
 		prep_temp_blob(temp, one->data, one->size,
 			       one->sha1, one->mode);
@@ -393,11 +551,13 @@ static void remove_tempfile_on_signal(int signo)
  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
  *
  */
-static void run_external_diff(const char *name,
+static void run_external_diff(const char *pgm,
+			      const char *name,
 			      const char *other,
 			      struct diff_filespec *one,
 			      struct diff_filespec *two,
-			      const char *xfrm_msg)
+			      const char *xfrm_msg,
+			      int complete_rewrite)
 {
 	struct diff_tempfile *temp = diff_temp;
 	pid_t pid;
@@ -421,7 +581,6 @@ static void run_external_diff(const char *name,
 	if (pid < 0)
 		die("unable to fork");
 	if (!pid) {
-		const char *pgm = external_diff();
 		if (pgm) {
 			if (one && two) {
 				const char *exec_arg[10];
@@ -448,7 +607,8 @@ static void run_external_diff(const char *name,
 		 * otherwise we use the built-in one.
 		 */
 		if (one && two)
-			builtin_diff(name, other ? : name, temp, xfrm_msg);
+			builtin_diff(name, other ? : name, temp, xfrm_msg,
+				     complete_rewrite);
 		else
 			printf("* Unmerged path %s\n", name);
 		exit(0);
@@ -471,9 +631,145 @@ static void run_external_diff(const char *name,
 	remove_tempfile();
 }
 
-void diff_setup(int reverse_diff_)
+static void run_diff(struct diff_filepair *p)
 {
-	reverse_diff = reverse_diff_;
+	const char *pgm = external_diff();
+	char msg_[PATH_MAX*2+200], *xfrm_msg;
+	struct diff_filespec *one;
+	struct diff_filespec *two;
+	const char *name;
+	const char *other;
+	int complete_rewrite = 0;
+
+	if (DIFF_PAIR_UNMERGED(p)) {
+		/* unmerged */
+		run_external_diff(pgm, p->one->path, NULL, NULL, NULL, NULL,
+				  0);
+		return;
+	}
+
+	name = p->one->path;
+	other = (strcmp(name, p->two->path) ? p->two->path : NULL);
+	one = p->one; two = p->two;
+	switch (p->status) {
+	case 'C':
+		sprintf(msg_,
+			"similarity index %d%%\n"
+			"copy from %s\n"
+			"copy to %s",
+			(int)(0.5 + p->score * 100.0/MAX_SCORE),
+			name, other);
+		xfrm_msg = msg_;
+		break;
+	case 'R':
+		sprintf(msg_,
+			"similarity index %d%%\n"
+			"rename from %s\n"
+			"rename to %s",
+			(int)(0.5 + p->score * 100.0/MAX_SCORE),
+			name, other);
+		xfrm_msg = msg_;
+		break;
+	case 'M':
+		if (p->score) {
+			sprintf(msg_,
+				"dissimilarity index %d%%",
+				(int)(0.5 + p->score * 100.0/MAX_SCORE));
+			xfrm_msg = msg_;
+			complete_rewrite = 1;
+			break;
+		}
+		/* fallthru */
+	default:
+		xfrm_msg = NULL;
+	}
+
+	if (!pgm &&
+	    DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
+	    (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
+		/* a filepair that changes between file and symlink
+		 * needs to be split into deletion and creation.
+		 */
+		struct diff_filespec *null = alloc_filespec(two->path);
+		run_external_diff(NULL, name, other, one, null, xfrm_msg, 0);
+		free(null);
+		null = alloc_filespec(one->path);
+		run_external_diff(NULL, name, other, null, two, xfrm_msg, 0);
+		free(null);
+	}
+	else
+		run_external_diff(pgm, name, other, one, two, xfrm_msg,
+				  complete_rewrite);
+}
+
+void diff_setup(int flags)
+{
+	if (flags & DIFF_SETUP_REVERSE)
+		reverse_diff = 1;
+	if (flags & DIFF_SETUP_USE_CACHE) {
+		if (!active_cache)
+			/* read-cache does not die even when it fails
+			 * so it is safe for us to do this here.  Also
+			 * it does not smudge active_cache or active_nr
+			 * when it fails, so we do not have to worry about
+			 * cleaning it up oufselves either.
+			 */
+			read_cache();
+	}
+	if (flags & DIFF_SETUP_USE_SIZE_CACHE)
+		use_size_cache = 1;
+	
+}
+
+static int parse_num(const char **cp_p)
+{
+	int num, scale, ch, cnt;
+	const char *cp = *cp_p;
+
+	cnt = num = 0;
+	scale = 1;
+	while ('0' <= (ch = *cp) && ch <= '9') {
+		if (cnt++ < 5) {
+			/* We simply ignore more than 5 digits precision. */
+			scale *= 10;
+			num = num * 10 + ch - '0';
+		}
+		*cp++;
+	}
+	*cp_p = cp;
+
+	/* user says num divided by scale and we say internally that
+	 * is MAX_SCORE * num / scale.
+	 */
+	return (MAX_SCORE * num / scale);
+}
+
+int diff_scoreopt_parse(const char *opt)
+{
+	int opt1, opt2, cmd;
+
+	if (*opt++ != '-')
+		return -1;
+	cmd = *opt++;
+	if (cmd != 'M' && cmd != 'C' && cmd != 'B')
+		return -1; /* that is not a -M, -C nor -B option */
+
+	opt1 = parse_num(&opt);
+	if (cmd != 'B')
+		opt2 = 0;
+	else {
+		if (*opt == 0)
+			opt2 = 0;
+		else if (*opt != '/')
+			return -1; /* we expect -B80/99 or -B80 */
+		else {
+			opt++;
+			opt2 = parse_num(&opt);
+		}
+	}
+	if (*opt != 0)
+		return -1;
+	return opt1 | (opt2 << 16);
 }
 
 struct diff_queue_struct diff_queued_diff;
@@ -496,24 +792,65 @@ struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
 	dp->one = one;
 	dp->two = two;
 	dp->score = 0;
-	dp->orig_order = queue->nr;
-	dp->rename_rank = 0;
+	dp->status = 0;
+	dp->source_stays = 0;
+	dp->broken_pair = 0;
 	diff_q(queue, dp);
 	return dp;
 }
 
-static void diff_flush_raw(struct diff_filepair *p)
+void diff_free_filepair(struct diff_filepair *p)
 {
-	if (DIFF_PAIR_UNMERGED(p)) {
-		printf("U %s%c", p->one->path, line_termination);
-		return;
+	diff_free_filespec_data(p->one);
+	diff_free_filespec_data(p->two);
+	free(p);
+}
+
+static void diff_flush_raw(struct diff_filepair *p,
+			   int line_termination,
+			   int inter_name_termination)
+{
+	int two_paths;
+	char status[10];
+
+	if (line_termination) {
+		const char *err = "path %s cannot be expressed without -z";
+		if (strchr(p->one->path, line_termination) ||
+		    strchr(p->one->path, inter_name_termination))
+			die(err, p->one->path);
+		if (strchr(p->two->path, line_termination) ||
+		    strchr(p->two->path, inter_name_termination))
+			die(err, p->two->path);
+	}
+
+	if (p->score)
+		sprintf(status, "%c%03d", p->status,
+			(int)(0.5 + p->score * 100.0/MAX_SCORE));
+	else {
+		status[0] = p->status;
+		status[1] = 0;
+	}
+	switch (p->status) {
+	case 'C': case 'R':
+		two_paths = 1;
+		break;
+	case 'N': case 'D':
+		two_paths = 0;
+		break;
+	default:
+		two_paths = 0;
+		break;
 	}
 	printf(":%06o %06o %s ",
 	       p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
-	printf("%s%c%s%c%s%c",
-	       sha1_to_hex(p->two->sha1), inter_name_termination,
-	       p->one->path, inter_name_termination,
-	       p->two->path, line_termination);
+	printf("%s %s%c%s",
+	       sha1_to_hex(p->two->sha1),
+	       status,
+	       inter_name_termination,
+	       p->one->path);
+	if (two_paths)
+		printf("%c%s", inter_name_termination, p->two->path);
+	putchar(line_termination);
 }
 
 int diff_unmodified_pair(struct diff_filepair *p)
@@ -531,9 +868,11 @@ int diff_unmodified_pair(struct diff_filepair *p)
 	one = p->one;
 	two = p->two;
 
-	/* deletion, addition, mode change and renames are all interesting. */
+	/* deletion, addition, mode or type change
+	 * and rename are all interesting.
+	 */
 	if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
-	    (one->mode != two->mode) ||
+	    DIFF_PAIR_MODE_CHANGED(p) ||
 	    strcmp(one->path, two->path))
 		return 0;
 
@@ -548,169 +887,248 @@ int diff_unmodified_pair(struct diff_filepair *p)
 	return 0;
 }
 
-static void diff_flush_patch(struct diff_filepair *p, const char *msg)
+static void diff_flush_patch(struct diff_filepair *p)
 {
-	const char *name, *other;
-
-	/* diffcore_prune() keeps "stay" entries for diff-raw
-	 * copy/rename detection, but when we are generating
-	 * patches we do not need them.
-	 */
 	if (diff_unmodified_pair(p))
 		return;
 
-	name = p->one->path;
-	other = (strcmp(name, p->two->path) ? p->two->path : NULL);
 	if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
 	    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
 		return; /* no tree diffs in patch format */ 
 
-	if (DIFF_PAIR_UNMERGED(p))
-		run_external_diff(name, NULL, NULL, NULL, NULL);
-	else
-		run_external_diff(name, other, p->one, p->two, msg);
+	run_diff(p);
 }
 
-int diff_needs_to_stay(struct diff_queue_struct *q, int i,
-		       struct diff_filespec *it)
+int diff_queue_is_empty(void)
 {
-	/* If it will be used in later entry (either stay or used
-	 * as the source of rename/copy), we need to copy, not rename.
-	 */
-	while (i < q->nr) {
-		struct diff_filepair *p = q->queue[i++];
-		if (!DIFF_FILE_VALID(p->two))
-			continue; /* removed is fine */
-		if (strcmp(p->one->path, it->path))
-			continue; /* not relevant */
-
-		/* p has its src set to *it and it is not a delete;
-		 * it will be used for in-place change, rename/copy,
-		 * or just stays there.  We cannot rename it out.
-		 */
-		return 1;
-	}
-	return 0;
+	struct diff_queue_struct *q = &diff_queued_diff;
+	int i;
+	for (i = 0; i < q->nr; i++)
+		if (!diff_unmodified_pair(q->queue[i]))
+			return 0;
+	return 1;
 }
 
-static int diff_used_as_source(struct diff_queue_struct *q, int lim,
-			       struct diff_filespec *it)
+#if DIFF_DEBUG
+void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
 {
-	int i;
-	for (i = 0; i < lim; i++) {
-		struct diff_filepair *p = q->queue[i++];
-		if (!strcmp(p->one->path, it->path))
-			return 1;
-	}
-	return 0;
+	fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
+		x, one ? : "",
+		s->path,
+		DIFF_FILE_VALID(s) ? "valid" : "invalid",
+		s->mode,
+		s->sha1_valid ? sha1_to_hex(s->sha1) : "");
+	fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
+		x, one ? : "",
+		s->size, s->xfrm_flags);
 }
 
-void diffcore_prune(void)
+void diff_debug_filepair(const struct diff_filepair *p, int i)
 {
-	/*
-	 * Although rename/copy detection wants to have "no-change"
-	 * entries fed into them, the downstream do not need to see
-	 * them, unless we had rename/copy for the same path earlier.
-	 * This function removes such entries.
-	 *
-	 * The applications that use rename/copy should:
-	 *
-	 * (1) feed change and "no-change" entries via diff_queue().
-	 * (2) call diffcore_rename, and any other future diffcore_xxx
-	 *     that would benefit by still having "no-change" entries.
-	 * (3) call diffcore_prune
-	 * (4) call other diffcore_xxx that do not need to see
-	 *     "no-change" entries.
-	 * (5) call diff_flush().
-	 */
-	struct diff_queue_struct *q = &diff_queued_diff;
-	struct diff_queue_struct outq;
-	int i;
-
-	outq.queue = NULL;
-	outq.nr = outq.alloc = 0;
+	diff_debug_filespec(p->one, i, "one");
+	diff_debug_filespec(p->two, i, "two");
+	fprintf(stderr, "score %d, status %c stays %d broken %d\n",
+		p->score, p->status ? : '?',
+		p->source_stays, p->broken_pair);
+}
 
+void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
+{
+	int i;
+	if (msg)
+		fprintf(stderr, "%s\n", msg);
+	fprintf(stderr, "q->nr = %d\n", q->nr);
 	for (i = 0; i < q->nr; i++) {
 		struct diff_filepair *p = q->queue[i];
-		if (!diff_unmodified_pair(p) ||
-		    diff_used_as_source(q, i, p->one))
-			diff_q(&outq, p);
-		else
-			free(p);
+		diff_debug_filepair(p, i);
 	}
-	free(q->queue);
-	*q = outq;
-	return;
-}
-
-static void diff_flush_one(struct diff_filepair *p, const char *msg)
-{
-	if (generate_patch)
-		diff_flush_patch(p, msg);
-	else
-		diff_flush_raw(p);
 }
+#endif
 
-int diff_queue_is_empty(void)
+static void diff_resolve_rename_copy(void)
 {
+	int i, j;
+	struct diff_filepair *p, *pp;
 	struct diff_queue_struct *q = &diff_queued_diff;
-	return q->nr == 0;
+
+	diff_debug_queue("resolve-rename-copy", q);
+
+	for (i = 0; i < q->nr; i++) {
+		p = q->queue[i];
+		p->status = 0; /* undecided */
+		if (DIFF_PAIR_UNMERGED(p))
+			p->status = 'U';
+		else if (!DIFF_FILE_VALID(p->one))
+			p->status = 'N';
+		else if (!DIFF_FILE_VALID(p->two))
+			p->status = 'D';
+		else if (DIFF_PAIR_TYPE_CHANGED(p))
+			p->status = 'T';
+
+		/* from this point on, we are dealing with a pair
+		 * whose both sides are valid and of the same type, i.e.
+		 * either in-place edit or rename/copy edit.
+		 */
+		else if (DIFF_PAIR_RENAME(p)) {
+			if (p->source_stays) {
+				p->status = 'C';
+				continue;
+			}
+			/* See if there is some other filepair that
+			 * copies from the same source as us.  If so
+			 * we are a copy.  Otherwise we are a rename.
+			 */
+			for (j = i + 1; j < q->nr; j++) {
+				pp = q->queue[j];
+				if (strcmp(pp->one->path, p->one->path))
+					continue; /* not us */
+				if (!DIFF_PAIR_RENAME(pp))
+					continue; /* not a rename/copy */
+				/* pp is a rename/copy from the same source */
+				p->status = 'C';
+				break;
+			}
+			if (!p->status)
+				p->status = 'R';
+		}
+		else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
+			 p->one->mode != p->two->mode)
+			p->status = 'M';
+		else {
+			/* This is a "no-change" entry and should not
+			 * happen anymore, but prepare for broken callers.
+			 */
+			error("feeding unmodified %s to diffcore",
+			      p->one->path);
+			p->status = 'X';
+		}
+	}
+	diff_debug_queue("resolve-rename-copy done", q);
 }
 
 void diff_flush(int diff_output_style)
 {
 	struct diff_queue_struct *q = &diff_queued_diff;
 	int i;
+	int line_termination = '\n';
+	int inter_name_termination = '\t';
 
-	generate_patch = 0;
-	switch (diff_output_style) {
-	case DIFF_FORMAT_HUMAN:
-		line_termination = '\n';
-		inter_name_termination = '\t';
-		break;
-	case DIFF_FORMAT_MACHINE:
+	if (diff_output_style == DIFF_FORMAT_MACHINE)
 		line_termination = inter_name_termination = 0;
-		break;
-	case DIFF_FORMAT_PATCH:
-		generate_patch = 1;
-		break;
-	}
-	for (i = 0; i < q->nr; i++) {
-		char msg_[PATH_MAX*2+200], *msg = NULL;
-		struct diff_filepair *p = q->queue[i];
-		if (strcmp(p->one->path, p->two->path)) {
-			/* This is rename or copy.  Which one is it? */
-			if (diff_needs_to_stay(q, i+1, p->one)) {
-				sprintf(msg_,
-					"similarity index %d%%\n"
-					"copy from %s\n"
-					"copy to %s\n",
-					(int)(0.5 + p->score * 100/MAX_SCORE),
-					p->one->path, p->two->path);
-			}
-			else
-				sprintf(msg_,
-					"similarity index %d%%\n"
-					"rename old %s\n"
-					"rename new %s\n",
-					(int)(0.5 + p->score * 100/MAX_SCORE),
-					p->one->path, p->two->path);
-			msg = msg_;
-		}
-		diff_flush_one(p, msg);
-	}
 
 	for (i = 0; i < q->nr; i++) {
 		struct diff_filepair *p = q->queue[i];
-		diff_free_filespec_data(p->one);
-		diff_free_filespec_data(p->two);
-		free(p);
+		if ((diff_output_style == DIFF_FORMAT_NO_OUTPUT) ||
+		    (p->status == 'X'))
+			continue;
+		if (p->status == 0)
+			die("internal error in diff-resolve-rename-copy");
+		switch (diff_output_style) {
+		case DIFF_FORMAT_PATCH:
+			diff_flush_patch(p);
+			break;
+		case DIFF_FORMAT_HUMAN:
+		case DIFF_FORMAT_MACHINE:
+			diff_flush_raw(p, line_termination,
+				       inter_name_termination);
+			break;
+		}
 	}
+	for (i = 0; i < q->nr; i++)
+		diff_free_filepair(q->queue[i]);
 	free(q->queue);
 	q->queue = NULL;
 	q->nr = q->alloc = 0;
 }
 
+static void diffcore_apply_filter(const char *filter)
+{
+	int i;
+	struct diff_queue_struct *q = &diff_queued_diff;
+	struct diff_queue_struct outq;
+	outq.queue = NULL;
+	outq.nr = outq.alloc = 0;
+
+	if (!filter)
+		return;
+
+	if (strchr(filter, 'A')) {
+		/* All-or-none */
+		int found;
+		for (i = found = 0; !found && i < q->nr; i++) {
+			struct diff_filepair *p = q->queue[i];
+			if (((p->status == 'M') &&
+			     ((p->score && strchr(filter, 'B')) ||
+			      (!p->score && strchr(filter, 'M')))) ||
+			    ((p->status != 'M') && strchr(filter, p->status)))
+				found++;
+		}
+		if (found)
+			return;
+
+		/* otherwise we will clear the whole queue
+		 * by copying the empty outq at the end of this
+		 * function, but first clear the current entries
+		 * in the queue.
+		 */
+		for (i = 0; i < q->nr; i++)
+			diff_free_filepair(q->queue[i]);
+	}
+	else {
+		/* Only the matching ones */
+		for (i = 0; i < q->nr; i++) {
+			struct diff_filepair *p = q->queue[i];
+			if (((p->status == 'M') &&
+			     ((p->score && strchr(filter, 'B')) ||
+			      (!p->score && strchr(filter, 'M')))) ||
+			    ((p->status != 'M') && strchr(filter, p->status)))
+				diff_q(&outq, p);
+			else
+				diff_free_filepair(p);
+		}
+	}
+	free(q->queue);
+	*q = outq;
+}
+
+void diffcore_std(const char **paths,
+		  int detect_rename, int rename_score,
+		  const char *pickaxe, int pickaxe_opts,
+		  int break_opt,
+		  const char *orderfile,
+		  const char *filter)
+{
+	if (paths && paths[0])
+		diffcore_pathspec(paths);
+	if (break_opt != -1)
+		diffcore_break(break_opt);
+	if (detect_rename)
+		diffcore_rename(detect_rename, rename_score);
+	if (break_opt != -1)
+		diffcore_merge_broken();
+	if (pickaxe)
+		diffcore_pickaxe(pickaxe, pickaxe_opts);
+	if (orderfile)
+		diffcore_order(orderfile);
+	diff_resolve_rename_copy();
+	diffcore_apply_filter(filter);
+}
+
+
+void diffcore_std_no_resolve(const char **paths,
+			     const char *pickaxe, int pickaxe_opts,
+			     const char *orderfile,
+			     const char *filter)
+{
+	if (paths && paths[0])
+		diffcore_pathspec(paths);
+	if (pickaxe)
+		diffcore_pickaxe(pickaxe, pickaxe_opts);
+	if (orderfile)
+		diffcore_order(orderfile);
+	diffcore_apply_filter(filter);
+}
+
 void diff_addremove(int addremove, unsigned mode,
 		    const unsigned char *sha1,
 		    const char *base, const char *path)
@@ -726,9 +1144,9 @@ void diff_addremove(int addremove, unsigned mode,
 	 * with something like '=' or '*' (I haven't decided
 	 * which but should not make any difference).
 	 * Feeding the same new and old to diff_change() 
-	 * also has the same effect.  diffcore_prune() should
-	 * be used to filter uninteresting ones out before the
-	 * final output happens.
+	 * also has the same effect.
+	 * Before the final output happens, they are pruned after
+	 * merged into rename/copy pairs as appropriate.
 	 */
 	if (reverse_diff)
 		addremove = (addremove == '+' ? '-' :
@@ -747,28 +1165,27 @@ void diff_addremove(int addremove, unsigned mode,
 	diff_queue(&diff_queued_diff, one, two);
 }
 
-void diff_guif(unsigned old_mode,
-	       unsigned new_mode,
-	       const unsigned char *old_sha1,
-	       const unsigned char *new_sha1,
-	       const char *old_path,
-	       const char *new_path)
+void diff_helper_input(unsigned old_mode,
+		       unsigned new_mode,
+		       const unsigned char *old_sha1,
+		       const unsigned char *new_sha1,
+		       const char *old_path,
+		       int status,
+		       int score,
+		       const char *new_path)
 {
 	struct diff_filespec *one, *two;
+	struct diff_filepair *dp;
 
-	if (reverse_diff) {
-		unsigned tmp;
-		const unsigned char *tmp_c;
-		tmp = old_mode; old_mode = new_mode; new_mode = tmp;
-		tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
-	}
 	one = alloc_filespec(old_path);
 	two = alloc_filespec(new_path);
 	if (old_mode)
 		fill_filespec(one, old_sha1, old_mode);
 	if (new_mode)
 		fill_filespec(two, new_sha1, new_mode);
-	diff_queue(&diff_queued_diff, one, two);
+	dp = diff_queue(&diff_queued_diff, one, two);
+	dp->score = score * MAX_SCORE / 100;
+	dp->status = status;
 }
 
 void diff_change(unsigned old_mode, unsigned new_mode,