X-Git-Url: https://git.verplant.org/?a=blobdiff_plain;f=diff.c;h=f7d4bc4b5aa479f6060e03e799aad76b9ad71d3d;hb=057c7d30183672d6ef96a9f3e87860058e1c08f8;hp=95488cdd9f026f897c688428f7090aa59d099bad;hpb=74c7cfa875448c71a18d21a0cc7c973afe759fa5;p=git.git

diff --git a/diff.c b/diff.c
index 95488cdd..f7d4bc4b 100644
--- a/diff.c
+++ b/diff.c
@@ -4,14 +4,25 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <signal.h>
+#include <limits.h>
 #include "cache.h"
 #include "diff.h"
+#include "diffcore.h"
 
-static char *diff_opts = "-pu";
+static const char *diff_opts = "-pu";
+static unsigned char null_sha1[20] = { 0, };
+
+static int detect_rename;
+static int reverse_diff;
+static int diff_raw_output = -1;
+static const char **pathspec;
+static int speccnt;
+static const char *pickaxe;
+static int minimum_score;
 
 static const char *external_diff(void)
 {
-	static char *external_diff_cmd = NULL;
+	static const char *external_diff_cmd = NULL;
 	static int done_preparing = 0;
 
 	if (done_preparing)
@@ -25,11 +36,11 @@ static const char *external_diff(void)
 	 *
 	 * GIT_DIFF_OPTS="-c";
 	 */
-	if (getenv("GIT_EXTERNAL_DIFF"))
-		external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
+	if (gitenv("GIT_EXTERNAL_DIFF"))
+		external_diff_cmd = gitenv("GIT_EXTERNAL_DIFF");
 
 	/* In case external diff fails... */
-	diff_opts = getenv("GIT_DIFF_OPTS") ? : diff_opts;
+	diff_opts = gitenv("GIT_DIFF_OPTS") ? : diff_opts;
 
 	done_preparing = 1;
 	return external_diff_cmd;
@@ -52,7 +63,7 @@ static char *sq_expand(const char *src)
 	const char *cp;
 	char *bp;
 
-	/* count bytes needed to store the quoted string. */ 
+	/* count bytes needed to store the quoted string. */
 	for (cnt = 1, cp = src; *cp; cnt++, cp++)
 		if (*cp == '\'')
 			cnt += 3;
@@ -72,30 +83,35 @@ static char *sq_expand(const char *src)
 }
 
 static struct diff_tempfile {
-	const char *name;
+	const char *name; /* filename external diff should read from */
 	char hex[41];
 	char mode[10];
 	char tmp_path[50];
 } diff_temp[2];
 
-static void builtin_diff(const char *name,
-			 struct diff_tempfile *temp)
+static void builtin_diff(const char *name_a,
+			 const char *name_b,
+			 struct diff_tempfile *temp,
+			 const char *xfrm_msg)
 {
-	int i, next_at;
+	int i, next_at, cmd_size;
 	const char *diff_cmd = "diff -L'%s%s' -L'%s%s'";
 	const char *diff_arg  = "'%s' '%s'||:"; /* "||:" is to return 0 */
 	const char *input_name_sq[2];
 	const char *path0[2];
 	const char *path1[2];
-	const char *name_sq = sq_expand(name);
+	const char *name_sq[2];
 	char *cmd;
-	
+
+	name_sq[0] = sq_expand(name_a);
+	name_sq[1] = sq_expand(name_b);
+
 	/* diff_cmd and diff_arg have 6 %s in total which makes
 	 * the sum of these strings 12 bytes larger than required.
 	 * we use 2 spaces around diff-opts, and we need to count
 	 * terminating NUL, so we subtract 9 here.
 	 */
-	int cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
+	cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
 			strlen(diff_arg) - 9);
 	for (i = 0; i < 2; i++) {
 		input_name_sq[i] = sq_expand(temp[i].name);
@@ -104,7 +120,7 @@ static void builtin_diff(const char *name,
 			path1[i] = "";
 		} else {
 			path0[i] = i ? "b/" : "a/";
-			path1[i] = name_sq;
+			path1[i] = name_sq[i];
 		}
 		cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
 			     strlen(input_name_sq[i]));
@@ -121,24 +137,51 @@ static void builtin_diff(const char *name,
 	next_at += snprintf(cmd+next_at, cmd_size-next_at,
 			    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])
-		printf("Created: %s (mode:%s)\n", name, temp[1].mode);
+		printf("new file mode %s\n", temp[1].mode);
 	else if (!path1[1][0])
-		printf("Deleted: %s\n", name);
-	else if (strcmp(temp[0].mode, temp[1].mode)) {
-		printf("Mode changed: %s (%s->%s)\n", name,
-		       temp[0].mode, temp[1].mode);
-		/* Be careful.  We do not want to diff between
-		 * symlink and a file.
-		 */
-		if (strncmp(temp[0].mode, "120", 3) !=
-		    strncmp(temp[1].mode, "120", 3))
+		printf("deleted file mode %s\n", temp[0].mode);
+	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);
+
+		if (strncmp(temp[0].mode, temp[1].mode, 3))
+			/* we do not run diff between different kind
+			 * of objects.
+			 */
 			exit(0);
 	}
 	fflush(NULL);
 	execlp("/bin/sh","sh", "-c", cmd, NULL);
 }
 
+struct diff_filespec *alloc_filespec(const char *path)
+{
+	int namelen = strlen(path);
+	struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
+	spec->path = (char *)(spec + 1);
+	strcpy(spec->path, path);
+	spec->should_free = spec->should_munmap = spec->file_valid = 0;
+	spec->xfrm_flags = 0;
+	spec->size = 0;
+	spec->data = 0;
+	return spec;
+}
+
+void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
+		   unsigned short mode)
+{
+	spec->mode = mode;
+	memcpy(spec->sha1, sha1, 20);
+	spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
+	spec->file_valid = 1;
+}
+
 /*
  * Given a name and sha1 pair, if the dircache tells us the file in
  * the work tree has that object contents, return true, so that
@@ -149,19 +192,19 @@ static int work_tree_matches(const char *name, const unsigned char *sha1)
 	struct cache_entry *ce;
 	struct stat st;
 	int pos, len;
-	
+
 	/* We do not read the cache ourselves here, because the
 	 * benchmark with my previous version that always reads cache
 	 * shows that it makes things worse for diff-tree comparing
 	 * two linux-2.6 kernel trees in an already checked out work
-	 * tree.  This is because most diff-tree comparison deals with
+	 * tree.  This is because most diff-tree comparisons deal with
 	 * only a small number of files, while reading the cache is
 	 * expensive for a large project, and its cost outweighs the
 	 * savings we get by not inflating the object to a temporary
 	 * file.  Practically, this code only helps when we are used
 	 * by diff-cache --cached, which does read the cache before
 	 * calling us.
-	 */ 
+	 */
 	if (!active_cache)
 		return 0;
 
@@ -171,13 +214,86 @@ static int work_tree_matches(const char *name, const unsigned char *sha1)
 		return 0;
 	ce = active_cache[pos];
 	if ((lstat(name, &st) < 0) ||
-	    !S_ISREG(st.st_mode) ||
-	    cache_match_stat(ce, &st) ||
+	    !S_ISREG(st.st_mode) || /* careful! */
+	    ce_match_stat(ce, &st) ||
 	    memcmp(sha1, ce->sha1, 20))
 		return 0;
+	/* we return 1 only when we can stat, it is a regular file,
+	 * stat information matches, and sha1 recorded in the cache
+	 * matches.  I.e. we know the file in the work tree really is
+	 * the same as the <name, sha1> pair.
+	 */
 	return 1;
 }
 
+/*
+ * 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 err = 0;
+	if (!s->file_valid)
+		die("internal error: asking to populate invalid file.");
+	if (S_ISDIR(s->mode))
+		return -1;
+
+	if (s->data)
+		return err;
+	if (!s->sha1_valid ||
+	    work_tree_matches(s->path, s->sha1)) {
+		struct stat st;
+		int fd;
+		if (lstat(s->path, &st) < 0) {
+			if (errno == ENOENT) {
+			err_empty:
+				err = -1;
+			empty:
+				s->data = "";
+				s->size = 0;
+				return err;
+			}
+		}
+		s->size = st.st_size;
+		if (!s->size)
+			goto empty;
+		if (S_ISLNK(st.st_mode)) {
+			int ret;
+			s->data = xmalloc(s->size);
+			s->should_free = 1;
+			ret = readlink(s->path, s->data, s->size);
+			if (ret < 0) {
+				free(s->data);
+				goto err_empty;
+			}
+			return 0;
+		}
+		fd = open(s->path, O_RDONLY);
+		if (fd < 0)
+			goto err_empty;
+		s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
+		s->should_munmap = 1;
+		close(fd);
+	}
+	else {
+		char type[20];
+		s->data = read_sha1_file(s->sha1, type, &s->size);
+		s->should_free = 1;
+	}
+	return 0;
+}
+
+void diff_free_filespec_data(struct diff_filespec *s)
+{
+	if (s->should_free)
+		free(s->data);
+	else if (s->should_munmap)
+		munmap(s->data, s->size);
+	s->should_free = s->should_munmap = 0;
+	s->data = 0;
+}
+
 static void prep_temp_blob(struct diff_tempfile *temp,
 			   void *blob,
 			   unsigned long size,
@@ -201,11 +317,8 @@ static void prep_temp_blob(struct diff_tempfile *temp,
 
 static void prepare_temp_file(const char *name,
 			      struct diff_tempfile *temp,
-			      struct diff_spec *one)
+			      struct diff_filespec *one)
 {
-	static unsigned char null_sha1[20] = { 0, };
-	int use_work_tree = 0;
-
 	if (!one->file_valid) {
 	not_a_valid_file:
 		/* A '-' entry produces this for file-2, and
@@ -217,18 +330,13 @@ static void prepare_temp_file(const char *name,
 		return;
 	}
 
-	if (one->sha1_valid &&
-	    (!memcmp(one->blob_sha1, null_sha1, sizeof(null_sha1)) ||
-	     work_tree_matches(name, one->blob_sha1)))
-		use_work_tree = 1;
-
-	if (!one->sha1_valid || use_work_tree) {
+	if (!one->sha1_valid ||
+	    work_tree_matches(name, one->sha1)) {
 		struct stat st;
-		temp->name = name;
-		if (lstat(temp->name, &st) < 0) {
+		if (lstat(name, &st) < 0) {
 			if (errno == ENOENT)
 				goto not_a_valid_file;
-			die("stat(%s): %s", temp->name, strerror(errno));
+			die("stat(%s): %s", name, strerror(errno));
 		}
 		if (S_ISLNK(st.st_mode)) {
 			int ret;
@@ -240,31 +348,27 @@ static void prepare_temp_file(const char *name,
 				die("readlink(%s)", name);
 			prep_temp_blob(temp, buf, st.st_size,
 				       (one->sha1_valid ?
-					one->blob_sha1 : null_sha1),
+					one->sha1 : null_sha1),
 				       (one->sha1_valid ?
 					one->mode : S_IFLNK));
 		}
 		else {
+			/* we can borrow from the file in the work tree */
+			temp->name = name;
 			if (!one->sha1_valid)
 				strcpy(temp->hex, sha1_to_hex(null_sha1));
 			else
-				strcpy(temp->hex, sha1_to_hex(one->blob_sha1));
+				strcpy(temp->hex, sha1_to_hex(one->sha1));
 			sprintf(temp->mode, "%06o",
 				S_IFREG |ce_permissions(st.st_mode));
 		}
 		return;
 	}
 	else {
-		void *blob;
-		char type[20];
-		unsigned long size;
-
-		blob = read_sha1_file(one->blob_sha1, type, &size);
-		if (!blob || strcmp(type, "blob"))
-			die("unable to read blob object for %s (%s)",
-			    name, sha1_to_hex(one->blob_sha1));
-		prep_temp_blob(temp, blob, size, one->blob_sha1, one->mode);
-		free(blob);
+		if (diff_populate_filespec(one))
+			die("cannot read data blob for %s", one->path);
+		prep_temp_blob(temp, one->data, one->size,
+			       one->sha1, one->mode);
 	}
 }
 
@@ -284,24 +388,48 @@ static void remove_tempfile_on_signal(int signo)
 	remove_tempfile();
 }
 
+static int matches_pathspec(const char *name)
+{
+	int i;
+	int namelen;
+
+	if (speccnt == 0)
+		return 1;
+
+	namelen = strlen(name);
+	for (i = 0; i < speccnt; i++) {
+		int speclen = strlen(pathspec[i]);
+		if (! strncmp(pathspec[i], name, speclen) &&
+		    speclen <= namelen &&
+		    (name[speclen] == 0 || name[speclen] == '/'))
+			return 1;
+	}
+	return 0;
+}
+
 /* An external diff command takes:
  *
  * diff-cmd name infile1 infile1-sha1 infile1-mode \
- *               infile2 infile2-sha1 infile2-mode.
+ *               infile2 infile2-sha1 infile2-mode [ rename-to ]
  *
  */
-void run_external_diff(const char *name,
-		       struct diff_spec *one,
-		       struct diff_spec *two)
+static void run_external_diff(const char *name,
+			      const char *other,
+			      struct diff_filespec *one,
+			      struct diff_filespec *two,
+			      const char *xfrm_msg)
 {
 	struct diff_tempfile *temp = diff_temp;
 	pid_t pid;
 	int status;
 	static int atexit_asked = 0;
 
+	if (!matches_pathspec(name) && (!other || !matches_pathspec(other)))
+		return;
+
 	if (one && two) {
 		prepare_temp_file(name, &temp[0], one);
-		prepare_temp_file(name, &temp[1], two);
+		prepare_temp_file(other ? : name, &temp[1], two);
 		if (! atexit_asked &&
 		    (temp[0].name == temp[0].tmp_path ||
 		     temp[1].name == temp[1].tmp_path)) {
@@ -318,12 +446,24 @@ void run_external_diff(const char *name,
 	if (!pid) {
 		const char *pgm = external_diff();
 		if (pgm) {
-			if (one && two)
-				execlp(pgm, pgm,
-				       name,
-				       temp[0].name, temp[0].hex, temp[0].mode,
-				       temp[1].name, temp[1].hex, temp[1].mode,
-				       NULL);
+			if (one && two) {
+				const char *exec_arg[10];
+				const char **arg = &exec_arg[0];
+				*arg++ = pgm;
+				*arg++ = name;
+				*arg++ = temp[0].name;
+				*arg++ = temp[0].hex;
+				*arg++ = temp[0].mode;
+				*arg++ = temp[1].name;
+				*arg++ = temp[1].hex;
+				*arg++ = temp[1].mode;
+				if (other) {
+					*arg++ = other;
+					*arg++ = xfrm_msg;
+				}
+				*arg = 0;
+				execvp(pgm, (char *const*) exec_arg);
+			}
 			else
 				execlp(pgm, pgm, name, NULL);
 		}
@@ -331,7 +471,7 @@ void run_external_diff(const char *name,
 		 * otherwise we use the built-in one.
 		 */
 		if (one && two)
-			builtin_diff(name, temp);
+			builtin_diff(name, other ? : name, temp, xfrm_msg);
 		else
 			printf("* Unmerged path %s\n", name);
 		exit(0);
@@ -354,29 +494,206 @@ void run_external_diff(const char *name,
 	remove_tempfile();
 }
 
+int diff_scoreopt_parse(const char *opt)
+{
+	int diglen, num, scale, i;
+	if (opt[0] != '-' || (opt[1] != 'M' && opt[1] != 'C'))
+		return -1; /* that is not a -M nor -C option */
+	diglen = strspn(opt+2, "0123456789");
+	if (diglen == 0 || strlen(opt+2) != diglen)
+		return 0; /* use default */
+	sscanf(opt+2, "%d", &num);
+	for (i = 0, scale = 1; i < diglen; i++)
+		scale *= 10;
+
+	/* user says num divided by scale and we say internally that
+	 * is MAX_SCORE * num / scale.
+	 */
+	return MAX_SCORE * num / scale;
+}
+
+void diff_setup(int detect_rename_, int minimum_score_,
+		const char *pickaxe_,
+		int reverse_diff_, int diff_raw_output_,
+		const char **pathspec_, int speccnt_)
+{
+	detect_rename = detect_rename_;
+	reverse_diff = reverse_diff_;
+	pathspec = pathspec_;
+	diff_raw_output = diff_raw_output_;
+	speccnt = speccnt_;
+	minimum_score = minimum_score_ ? : DEFAULT_MINIMUM_SCORE;
+	pickaxe = pickaxe_;
+}
+
+static struct diff_queue_struct queued_diff;
+
+struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
+				  struct diff_filespec *one,
+				  struct diff_filespec *two)
+{
+	struct diff_filepair *dp = xmalloc(sizeof(*dp));
+	dp->one = one;
+	dp->two = two;
+	dp->xfrm_msg = 0;
+	dp->orig_order = queue->nr;
+	dp->xfrm_work = 0;
+	if (queue->alloc <= queue->nr) {
+		queue->alloc = alloc_nr(queue->alloc);
+		queue->queue = xrealloc(queue->queue,
+				       sizeof(dp) * queue->alloc);
+	}
+	queue->queue[queue->nr++] = dp;
+	return dp;
+}
+
+static const char *git_object_type(unsigned mode)
+{
+	return S_ISDIR(mode) ? "tree" : "blob";
+}
+
+static void diff_flush_raw(struct diff_filepair *p)
+{
+	struct diff_filespec *it;
+	int addremove;
+
+	/* raw output does not have a way to express rename nor copy */
+	if (strcmp(p->one->path, p->two->path))
+		return;
+
+	if (p->one->file_valid && p->two->file_valid) {
+		char hex[41];
+		strcpy(hex, sha1_to_hex(p->one->sha1));
+		printf("*%06o->%06o %s %s->%s %s%c",
+		       p->one->mode, p->two->mode,
+		       git_object_type(p->one->mode),
+		       hex, sha1_to_hex(p->two->sha1),
+		       p->one->path, diff_raw_output);
+		return;
+	}
+
+	if (p->one->file_valid) {
+		it = p->one;
+		addremove = '-';
+	} else {
+		it = p->two;
+		addremove = '+';
+	}
+
+	printf("%c%06o %s %s %s%c",
+	       addremove,
+	       it->mode, git_object_type(it->mode),
+	       sha1_to_hex(it->sha1), it->path, diff_raw_output);
+}
+
+static void diff_flush_patch(struct diff_filepair *p)
+{
+	const char *name, *other;
+
+	name = p->one->path;
+	other = (strcmp(name, p->two->path) ? p->two->path : NULL);
+	if ((p->one->file_valid && S_ISDIR(p->one->mode)) ||
+	    (p->two->file_valid && S_ISDIR(p->two->mode)))
+		return; /* no tree diffs in patch format */ 
+
+	run_external_diff(name, other, p->one, p->two, p->xfrm_msg);
+}
+
+static int identical(struct diff_filespec *one, struct diff_filespec *two)
+{
+	/* This function is written stricter than necessary to support
+	 * the currently implemented transformers, but the idea is to
+	 * let transformers to produce diff_filepairs any way they want,
+	 * and filter and clean them up here before producing the output.
+	 */
+
+	if (!one->file_valid && !two->file_valid)
+		return 1; /* not interesting */
+
+	/* deletion, addition, mode change and renames are all interesting. */
+	if ((one->file_valid != two->file_valid) || (one->mode != two->mode) ||
+	    strcmp(one->path, two->path))
+		return 0;
+
+	/* both are valid and point at the same path.  that is, we are
+	 * dealing with a change.
+	 */
+	if (one->sha1_valid && two->sha1_valid &&
+	    !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
+		return 1; /* no change */
+	if (!one->sha1_valid && !two->sha1_valid)
+		return 1; /* both look at the same file on the filesystem. */
+	return 0;
+}
+
+static void diff_flush_one(struct diff_filepair *p)
+{
+	if (identical(p->one, p->two))
+		return;
+	if (0 <= diff_raw_output)
+		diff_flush_raw(p);
+	else
+		diff_flush_patch(p);
+}
+
+void diff_flush(void)
+{
+	struct diff_queue_struct *q = &queued_diff;
+	int i;
+
+	if (detect_rename)
+		diff_detect_rename(q, detect_rename, minimum_score);
+	if (pickaxe)
+		diff_pickaxe(q, pickaxe);
+	for (i = 0; i < q->nr; i++)
+		diff_flush_one(q->queue[i]);
+
+	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->xfrm_msg);
+		free(p);
+	}
+	free(q->queue);
+	q->queue = NULL;
+	q->nr = q->alloc = 0;
+}
+
 void diff_addremove(int addremove, unsigned mode,
 		    const unsigned char *sha1,
 		    const char *base, const char *path)
 {
 	char concatpath[PATH_MAX];
-	struct diff_spec spec[2], *one, *two;
+	struct diff_filespec *one, *two;
+
+	/* This may look odd, but it is a preparation for
+	 * feeding "there are unchanged files which should
+	 * not produce diffs, but when you are doing copy
+	 * detection you would need them, so here they are"
+	 * entries to the diff-core.  They will be prefixed
+	 * with something like '=' or '*' (I haven't decided
+	 * which but should not make any difference).
+	 * Feeding the same new and old to diff_change() should
+	 * also have the same effect.  diff_flush() should
+	 * filter the identical ones out at the final output
+	 * stage.
+	 */
+	if (reverse_diff)
+		addremove = (addremove == '+' ? '-' :
+			     addremove == '-' ? '+' : addremove);
 
-	memcpy(spec[0].blob_sha1, sha1, 20);
-	spec[0].mode = mode;
-	spec[0].sha1_valid = spec[0].file_valid = 1;
-	spec[1].file_valid = 0;
+	if (!path) path = "";
+	sprintf(concatpath, "%s%s", base, path);
+	one = alloc_filespec(concatpath);
+	two = alloc_filespec(concatpath);
 
-	if (addremove == '+') {
-		one = spec + 1; two = spec;
-	} else {
-		one = spec; two = one + 1;
-	}
-	
-	if (path) {
-		strcpy(concatpath, base);
-		strcat(concatpath, path);
-	}
-	run_external_diff(path ? concatpath : base, one, two);
+	if (addremove != '+')
+		fill_filespec(one, sha1, mode);
+	if (addremove != '-')
+		fill_filespec(two, sha1, mode);
+
+	diff_queue(&queued_diff, one, two);
 }
 
 void diff_change(unsigned old_mode, unsigned new_mode,
@@ -384,23 +701,29 @@ void diff_change(unsigned old_mode, unsigned new_mode,
 		 const unsigned char *new_sha1,
 		 const char *base, const char *path) {
 	char concatpath[PATH_MAX];
-	struct diff_spec spec[2];
-
-	memcpy(spec[0].blob_sha1, old_sha1, 20);
-	spec[0].mode = old_mode;
-	memcpy(spec[1].blob_sha1, new_sha1, 20);
-	spec[1].mode = new_mode;
-	spec[0].sha1_valid = spec[0].file_valid = 1;
-	spec[1].sha1_valid = spec[1].file_valid = 1;
-
-	if (path) {
-		strcpy(concatpath, base);
-		strcat(concatpath, path);
+	struct diff_filespec *one, *two;
+
+	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;
 	}
-	run_external_diff(path ? concatpath : base, &spec[0], &spec[1]);
+	if (!path) path = "";
+	sprintf(concatpath, "%s%s", base, path);
+	one = alloc_filespec(concatpath);
+	two = alloc_filespec(concatpath);
+	fill_filespec(one, old_sha1, old_mode);
+	fill_filespec(two, new_sha1, new_mode);
+
+	diff_queue(&queued_diff, one, two);
 }
 
 void diff_unmerge(const char *path)
 {
-	run_external_diff(path, NULL, NULL);
+	if (0 <= diff_raw_output) {
+		printf("U %s%c", path, diff_raw_output);
+		return;
+	}
+	run_external_diff(path, NULL, NULL, NULL, NULL);
 }