diff --git a/Makefile b/Makefile
index a1ec04e3a0..b6d8804d4b 100644
--- a/Makefile
+++ b/Makefile
@@ -165,7 +165,7 @@ PROGRAMS = \
 	git-upload-pack$X git-verify-pack$X git-write-tree$X \
 	git-update-ref$X git-symbolic-ref$X git-check-ref-format$X \
 	git-name-rev$X git-pack-redundant$X git-repo-config$X git-var$X \
-	git-describe$X git-merge-tree$X
+	git-describe$X git-merge-tree$X git-blame$X
 
 # what 'all' will build and 'install' will install, in gitexecdir
 ALL_PROGRAMS = $(PROGRAMS) $(SIMPLE_PROGRAMS) $(SCRIPTS)
diff --git a/blame.c b/blame.c
new file mode 100644
index 0000000000..7308c36d23
--- /dev/null
+++ b/blame.c
@@ -0,0 +1,562 @@
+/*
+ * Copyright (C) 2006, Fredrik Kuivinen <freku045@student.liu.se>
+ */
+
+#include <assert.h>
+#include <time.h>
+#include <sys/time.h>
+
+#include "cache.h"
+#include "refs.h"
+#include "tag.h"
+#include "commit.h"
+#include "tree.h"
+#include "blob.h"
+#include "diff.h"
+#include "revision.h"
+
+#define DEBUG 0
+
+struct commit **blame_lines;
+int num_blame_lines;
+
+struct util_info {
+	int *line_map;
+	unsigned char sha1[20];	/* blob sha, not commit! */
+	char *buf;
+	unsigned long size;
+	int num_lines;
+//    const char* path;
+};
+
+struct chunk {
+	int off1, len1;	// ---
+	int off2, len2;	// +++
+};
+
+struct patch {
+	struct chunk *chunks;
+	int num;
+};
+
+static void get_blob(struct commit *commit);
+
+/* Only used for statistics */
+static int num_get_patch = 0;
+static int num_commits = 0;
+static int patch_time = 0;
+
+#define TEMPFILE_PATH_LEN 60
+static struct patch *get_patch(struct commit *commit, struct commit *other)
+{
+	struct patch *ret;
+	struct util_info *info_c = (struct util_info *)commit->object.util;
+	struct util_info *info_o = (struct util_info *)other->object.util;
+	char tmp_path1[TEMPFILE_PATH_LEN], tmp_path2[TEMPFILE_PATH_LEN];
+	char diff_cmd[TEMPFILE_PATH_LEN*2 + 20];
+	struct timeval tv_start, tv_end;
+	int fd;
+	FILE *fin;
+	char buf[1024];
+
+	ret = xmalloc(sizeof(struct patch));
+	ret->chunks = NULL;
+	ret->num = 0;
+
+	get_blob(commit);
+	get_blob(other);
+
+	gettimeofday(&tv_start, NULL);
+
+	fd = git_mkstemp(tmp_path1, TEMPFILE_PATH_LEN, "git-blame-XXXXXX");
+	if (fd < 0)
+		die("unable to create temp-file: %s", strerror(errno));
+
+	if (xwrite(fd, info_c->buf, info_c->size) != info_c->size)
+		die("write failed: %s", strerror(errno));
+	close(fd);
+
+	fd = git_mkstemp(tmp_path2, TEMPFILE_PATH_LEN, "git-blame-XXXXXX");
+	if (fd < 0)
+		die("unable to create temp-file: %s", strerror(errno));
+
+	if (xwrite(fd, info_o->buf, info_o->size) != info_o->size)
+		die("write failed: %s", strerror(errno));
+	close(fd);
+
+	sprintf(diff_cmd, "diff -u0 %s %s", tmp_path1, tmp_path2);
+	fin = popen(diff_cmd, "r");
+	if (!fin)
+		die("popen failed: %s", strerror(errno));
+
+	while (fgets(buf, sizeof(buf), fin)) {
+		struct chunk *chunk;
+		char *start, *sp;
+
+		if (buf[0] != '@' || buf[1] != '@')
+			continue;
+
+		if (DEBUG)
+			printf("chunk line: %s", buf);
+		ret->num++;
+		ret->chunks = xrealloc(ret->chunks,
+				       sizeof(struct chunk) * ret->num);
+		chunk = &ret->chunks[ret->num - 1];
+
+		assert(!strncmp(buf, "@@ -", 4));
+
+		start = buf + 4;
+		sp = index(start, ' ');
+		*sp = '\0';
+		if (index(start, ',')) {
+			int ret =
+			    sscanf(start, "%d,%d", &chunk->off1, &chunk->len1);
+			assert(ret == 2);
+		} else {
+			int ret = sscanf(start, "%d", &chunk->off1);
+			assert(ret == 1);
+			chunk->len1 = 1;
+		}
+		*sp = ' ';
+
+		start = sp + 1;
+		sp = index(start, ' ');
+		*sp = '\0';
+		if (index(start, ',')) {
+			int ret =
+			    sscanf(start, "%d,%d", &chunk->off2, &chunk->len2);
+			assert(ret == 2);
+		} else {
+			int ret = sscanf(start, "%d", &chunk->off2);
+			assert(ret == 1);
+			chunk->len2 = 1;
+		}
+		*sp = ' ';
+
+		if (chunk->len1 == 0)
+			chunk->off1++;
+		if (chunk->len2 == 0)
+			chunk->off2++;
+
+		if (chunk->off1 > 0)
+			chunk->off1--;
+		if (chunk->off2 > 0)
+			chunk->off2--;
+
+		assert(chunk->off1 >= 0);
+		assert(chunk->off2 >= 0);
+	}
+	pclose(fin);
+	unlink(tmp_path1);
+	unlink(tmp_path2);
+
+	gettimeofday(&tv_end, NULL);
+	patch_time += 1000000 * (tv_end.tv_sec - tv_start.tv_sec) +
+		tv_end.tv_usec - tv_start.tv_usec;
+
+	num_get_patch++;
+	return ret;
+}
+
+static void free_patch(struct patch *p)
+{
+	free(p->chunks);
+	free(p);
+}
+
+static int get_blob_sha1_internal(unsigned char *sha1, const char *base,
+				  int baselen, const char *pathname,
+				  unsigned mode, int stage);
+
+static unsigned char blob_sha1[20];
+static int get_blob_sha1(struct tree *t, const char *pathname,
+			 unsigned char *sha1)
+{
+	int i;
+	const char *pathspec[2];
+	pathspec[0] = pathname;
+	pathspec[1] = NULL;
+	memset(blob_sha1, 0, sizeof(blob_sha1));
+	read_tree_recursive(t, "", 0, 0, pathspec, get_blob_sha1_internal);
+
+	for (i = 0; i < 20; i++) {
+		if (blob_sha1[i] != 0)
+			break;
+	}
+
+	if (i == 20)
+		return -1;
+
+	memcpy(sha1, blob_sha1, 20);
+	return 0;
+}
+
+static int get_blob_sha1_internal(unsigned char *sha1, const char *base,
+				  int baselen, const char *pathname,
+				  unsigned mode, int stage)
+{
+	if (S_ISDIR(mode))
+		return READ_TREE_RECURSIVE;
+
+	memcpy(blob_sha1, sha1, 20);
+	return -1;
+}
+
+static void get_blob(struct commit *commit)
+{
+	struct util_info *info = commit->object.util;
+	char type[20];
+
+	if (info->buf)
+		return;
+
+	info->buf = read_sha1_file(info->sha1, type, &info->size);
+
+	assert(!strcmp(type, "blob"));
+}
+
+/* For debugging only */
+static void print_patch(struct patch *p)
+{
+	int i;
+	printf("Num chunks: %d\n", p->num);
+	for (i = 0; i < p->num; i++) {
+		printf("%d,%d %d,%d\n", p->chunks[i].off1, p->chunks[i].len1,
+		       p->chunks[i].off2, p->chunks[i].len2);
+	}
+}
+
+/* For debugging only */
+static void print_map(struct commit *cmit, struct commit *other)
+{
+	struct util_info *util = cmit->object.util;
+	struct util_info *util2 = other->object.util;
+
+	int i;
+	int max =
+	    util->num_lines >
+	    util2->num_lines ? util->num_lines : util2->num_lines;
+	int num;
+
+	for (i = 0; i < max; i++) {
+		printf("i: %d ", i);
+		num = -1;
+
+		if (i < util->num_lines) {
+			num = util->line_map[i];
+			printf("%d\t", num);
+		} else
+			printf("\t");
+
+		if (i < util2->num_lines) {
+			int num2 = util2->line_map[i];
+			printf("%d\t", num2);
+			if (num != -1 && num2 != num)
+				printf("---");
+		} else
+			printf("\t");
+
+		printf("\n");
+	}
+}
+
+// p is a patch from commit to other.
+static void fill_line_map(struct commit *commit, struct commit *other,
+			  struct patch *p)
+{
+	struct util_info *util = commit->object.util;
+	struct util_info *util2 = other->object.util;
+	int *map = util->line_map;
+	int *map2 = util2->line_map;
+	int cur_chunk = 0;
+	int i1, i2;
+
+	if (p->num && DEBUG)
+		print_patch(p);
+
+	if (DEBUG)
+		printf("num lines 1: %d num lines 2: %d\n", util->num_lines,
+		       util2->num_lines);
+
+	for (i1 = 0, i2 = 0; i1 < util->num_lines; i1++, i2++) {
+		struct chunk *chunk = NULL;
+		if (cur_chunk < p->num)
+			chunk = &p->chunks[cur_chunk];
+
+		if (chunk && chunk->off1 == i1) {
+			if (DEBUG && i2 != chunk->off2)
+				printf("i2: %d off2: %d\n", i2, chunk->off2);
+
+			assert(i2 == chunk->off2);
+
+			i1--;
+			i2--;
+			if (chunk->len1 > 0)
+				i1 += chunk->len1;
+
+			if (chunk->len2 > 0)
+				i2 += chunk->len2;
+
+			cur_chunk++;
+		} else {
+			if (i2 >= util2->num_lines)
+				break;
+
+			if (map[i1] != map2[i2] && map[i1] != -1) {
+				if (DEBUG)
+					printf("map: i1: %d %d %p i2: %d %d %p\n",
+					       i1, map[i1],
+					       i1 != -1 ? blame_lines[map[i1]] : NULL,
+					       i2, map2[i2],
+					       i2 != -1 ? blame_lines[map2[i2]] : NULL);
+				if (map2[i2] != -1 &&
+				    blame_lines[map[i1]] &&
+				    !blame_lines[map2[i2]])
+					map[i1] = map2[i2];
+			}
+
+			if (map[i1] == -1 && map2[i2] != -1)
+				map[i1] = map2[i2];
+		}
+
+		if (DEBUG > 1)
+			printf("l1: %d l2: %d i1: %d i2: %d\n",
+			       map[i1], map2[i2], i1, i2);
+	}
+}
+
+static int map_line(struct commit *commit, int line)
+{
+	struct util_info *info = commit->object.util;
+	assert(line >= 0 && line < info->num_lines);
+	return info->line_map[line];
+}
+
+static int fill_util_info(struct commit *commit, const char *path)
+{
+	struct util_info *util;
+	if (commit->object.util)
+		return 0;
+
+	util = xmalloc(sizeof(struct util_info));
+
+	if (get_blob_sha1(commit->tree, path, util->sha1)) {
+		free(util);
+		return 1;
+	} else {
+		util->buf = NULL;
+		util->size = 0;
+		util->line_map = NULL;
+		util->num_lines = -1;
+		commit->object.util = util;
+		return 0;
+	}
+}
+
+static void alloc_line_map(struct commit *commit)
+{
+	struct util_info *util = commit->object.util;
+	int i;
+
+	if (util->line_map)
+		return;
+
+	get_blob(commit);
+
+	util->num_lines = 0;
+	for (i = 0; i < util->size; i++) {
+		if (util->buf[i] == '\n')
+			util->num_lines++;
+	}
+	if(util->buf[util->size - 1] != '\n')
+		util->num_lines++;
+
+	util->line_map = xmalloc(sizeof(int) * util->num_lines);
+
+	for (i = 0; i < util->num_lines; i++)
+		util->line_map[i] = -1;
+}
+
+static void init_first_commit(struct commit* commit, const char* filename)
+{
+	struct util_info* util;
+	int i;
+
+	if (fill_util_info(commit, filename))
+		die("fill_util_info failed");
+
+	alloc_line_map(commit);
+
+	util = commit->object.util;
+	num_blame_lines = util->num_lines;
+
+	for (i = 0; i < num_blame_lines; i++)
+		util->line_map[i] = i;
+}
+
+
+static void process_commits(struct rev_info *rev, const char *path,
+			    struct commit** initial)
+{
+	int i;
+	struct util_info* util;
+	int lines_left;
+	int *blame_p;
+	int *new_lines;
+	int new_lines_len;
+
+	struct commit* commit = get_revision(rev);
+	assert(commit);
+	init_first_commit(commit, path);
+
+	util = commit->object.util;
+	num_blame_lines = util->num_lines;
+	blame_lines = xmalloc(sizeof(struct commit *) * num_blame_lines);
+	for (i = 0; i < num_blame_lines; i++)
+		blame_lines[i] = NULL;
+
+	lines_left = num_blame_lines;
+	blame_p = xmalloc(sizeof(int) * num_blame_lines);
+	new_lines = xmalloc(sizeof(int) * num_blame_lines);
+	do {
+		struct commit_list *parents;
+		int num_parents;
+		struct util_info *util;
+
+		if (DEBUG)
+			printf("\nProcessing commit: %d %s\n", num_commits,
+			       sha1_to_hex(commit->object.sha1));
+
+		if (lines_left == 0)
+			return;
+
+		num_commits++;
+		memset(blame_p, 0, sizeof(int) * num_blame_lines);
+		new_lines_len = 0;
+		num_parents = 0;
+		for (parents = commit->parents;
+		     parents != NULL; parents = parents->next)
+			num_parents++;
+
+		if(num_parents == 0)
+			*initial = commit;
+
+		if(fill_util_info(commit, path))
+			continue;
+
+		alloc_line_map(commit);
+		util = commit->object.util;
+
+		for (parents = commit->parents;
+		     parents != NULL; parents = parents->next) {
+			struct commit *parent = parents->item;
+			struct patch *patch;
+
+			if (parse_commit(parent) < 0)
+				die("parse_commit error");
+
+			if (DEBUG)
+				printf("parent: %s\n",
+				       sha1_to_hex(parent->object.sha1));
+
+			if(fill_util_info(parent, path)) {
+				num_parents--;
+				continue;
+			}
+
+			patch = get_patch(parent, commit);
+                        alloc_line_map(parent);
+                        fill_line_map(parent, commit, patch);
+
+                        for (i = 0; i < patch->num; i++) {
+                            int l;
+                            for (l = 0; l < patch->chunks[i].len2; l++) {
+                                int mapped_line =
+                                    map_line(commit, patch->chunks[i].off2 + l);
+                                if (mapped_line != -1) {
+                                    blame_p[mapped_line]++;
+                                    if (blame_p[mapped_line] == num_parents)
+                                        new_lines[new_lines_len++] = mapped_line;
+                                }
+                            }
+			}
+                        free_patch(patch);
+		}
+
+		if (DEBUG)
+			printf("parents: %d\n", num_parents);
+
+		for (i = 0; i < new_lines_len; i++) {
+			int mapped_line = new_lines[i];
+			if (blame_lines[mapped_line] == NULL) {
+				blame_lines[mapped_line] = commit;
+				lines_left--;
+				if (DEBUG)
+					printf("blame: mapped: %d i: %d\n",
+					       mapped_line, i);
+			}
+		}
+	} while ((commit = get_revision(rev)) != NULL);
+}
+
+int main(int argc, const char **argv)
+{
+	int i;
+	struct commit *initial = NULL;
+	unsigned char sha1[20];
+	const char* filename;
+	int num_args;
+	const char* args[10];
+	struct rev_info rev;
+
+	setup_git_directory();
+
+	if (argc != 3)
+		die("Usage: blame commit-ish file");
+
+
+	filename = argv[2];
+
+	{
+		struct commit* commit;
+		if (get_sha1(argv[1], sha1))
+			die("get_sha1 failed");
+		commit = lookup_commit_reference(sha1);
+
+		if (fill_util_info(commit, filename)) {
+			printf("%s not found in %s\n", filename, argv[1]);
+			return 1;
+		}
+	}
+
+	num_args = 0;
+	args[num_args++] = NULL;
+	args[num_args++] = "--topo-order";
+	args[num_args++] = "--remove-empty";
+	args[num_args++] = argv[1];
+	args[num_args++] = "--";
+	args[num_args++] = filename;
+	args[num_args] = NULL;
+
+	setup_revisions(num_args, args, &rev, "HEAD");
+	prepare_revision_walk(&rev);
+	process_commits(&rev, filename, &initial);
+
+	for (i = 0; i < num_blame_lines; i++) {
+		struct commit *c = blame_lines[i];
+		if (!c)
+			c = initial;
+
+		printf("%d %.8s\n", i, sha1_to_hex(c->object.sha1));
+// printf("%d %s\n", i, find_unique_abbrev(blame_lines[i]->object.sha1, 6));
+	}
+
+	if (DEBUG) {
+		printf("num get patch: %d\n", num_get_patch);
+		printf("num commits: %d\n", num_commits);
+		printf("patch time: %f\n", patch_time / 1000000.0);
+		printf("initial: %s\n", sha1_to_hex(initial->object.sha1));
+	}
+
+	return 0;
+}