Move 'builtin-*' into a 'builtin/' subdirectory

This shrinks the top-level directory a bit, and makes it much more
pleasant to use auto-completion on the thing. Instead of

	[torvalds@nehalem git]$ em buil<tab>
	Display all 180 possibilities? (y or n)
	[torvalds@nehalem git]$ em builtin-sh
	builtin-shortlog.c     builtin-show-branch.c  builtin-show-ref.c
	builtin-shortlog.o     builtin-show-branch.o  builtin-show-ref.o
	[torvalds@nehalem git]$ em builtin-shor<tab>
	builtin-shortlog.c  builtin-shortlog.o
	[torvalds@nehalem git]$ em builtin-shortlog.c

you get

	[torvalds@nehalem git]$ em buil<tab>		[type]
	builtin/   builtin.h
	[torvalds@nehalem git]$ em builtin		[auto-completes to]
	[torvalds@nehalem git]$ em builtin/sh<tab>	[type]
	shortlog.c     shortlog.o     show-branch.c  show-branch.o  show-ref.c     show-ref.o
	[torvalds@nehalem git]$ em builtin/sho		[auto-completes to]
	[torvalds@nehalem git]$ em builtin/shor<tab>	[type]
	shortlog.c  shortlog.o
	[torvalds@nehalem git]$ em builtin/shortlog.c

which doesn't seem all that different, but not having that annoying
break in "Display all 180 possibilities?" is quite a relief.

NOTE! If you do this in a clean tree (no object files etc), or using an
editor that has auto-completion rules that ignores '*.o' files, you
won't see that annoying 'Display all 180 possibilities?' message - it
will just show the choices instead.  I think bash has some cut-off
around 100 choices or something.

So the reason I see this is that I'm using an odd editory, and thus
don't have the rules to cut down on auto-completion.  But you can
simulate that by using 'ls' instead, or something similar.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2477 insertions, 0 deletions

diff --git a/builtin/blame.c b/builtin/blame.c
new file mode 100644
index 000000000..10f7eacf6
--- /dev/null
+++ b/builtin/blame.c
@@ -0,0 +1,2477 @@
+/*
+ * Blame
+ *
+ * Copyright (c) 2006, Junio C Hamano
+ */
+
+#include "cache.h"
+#include "builtin.h"
+#include "blob.h"
+#include "commit.h"
+#include "tag.h"
+#include "tree-walk.h"
+#include "diff.h"
+#include "diffcore.h"
+#include "revision.h"
+#include "quote.h"
+#include "xdiff-interface.h"
+#include "cache-tree.h"
+#include "string-list.h"
+#include "mailmap.h"
+#include "parse-options.h"
+#include "utf8.h"
+
+static char blame_usage[] = "git blame [options] [rev-opts] [rev] [--] file";
+
+static const char *blame_opt_usage[] = {
+	blame_usage,
+	"",
+	"[rev-opts] are documented in git-rev-list(1)",
+	NULL
+};
+
+static int longest_file;
+static int longest_author;
+static int max_orig_digits;
+static int max_digits;
+static int max_score_digits;
+static int show_root;
+static int reverse;
+static int blank_boundary;
+static int incremental;
+static int xdl_opts = XDF_NEED_MINIMAL;
+
+static enum date_mode blame_date_mode = DATE_ISO8601;
+static size_t blame_date_width;
+
+static struct string_list mailmap;
+
+#ifndef DEBUG
+#define DEBUG 0
+#endif
+
+/* stats */
+static int num_read_blob;
+static int num_get_patch;
+static int num_commits;
+
+#define PICKAXE_BLAME_MOVE		01
+#define PICKAXE_BLAME_COPY		02
+#define PICKAXE_BLAME_COPY_HARDER	04
+#define PICKAXE_BLAME_COPY_HARDEST	010
+
+/*
+ * blame for a blame_entry with score lower than these thresholds
+ * is not passed to the parent using move/copy logic.
+ */
+static unsigned blame_move_score;
+static unsigned blame_copy_score;
+#define BLAME_DEFAULT_MOVE_SCORE	20
+#define BLAME_DEFAULT_COPY_SCORE	40
+
+/* bits #0..7 in revision.h, #8..11 used for merge_bases() in commit.c */
+#define METAINFO_SHOWN		(1u<<12)
+#define MORE_THAN_ONE_PATH	(1u<<13)
+
+/*
+ * One blob in a commit that is being suspected
+ */
+struct origin {
+	int refcnt;
+	struct origin *previous;
+	struct commit *commit;
+	mmfile_t file;
+	unsigned char blob_sha1[20];
+	char path[FLEX_ARRAY];
+};
+
+/*
+ * Given an origin, prepare mmfile_t structure to be used by the
+ * diff machinery
+ */
+static void fill_origin_blob(struct origin *o, mmfile_t *file)
+{
+	if (!o->file.ptr) {
+		enum object_type type;
+		num_read_blob++;
+		file->ptr = read_sha1_file(o->blob_sha1, &type,
+					   (unsigned long *)(&(file->size)));
+		if (!file->ptr)
+			die("Cannot read blob %s for path %s",
+			    sha1_to_hex(o->blob_sha1),
+			    o->path);
+		o->file = *file;
+	}
+	else
+		*file = o->file;
+}
+
+/*
+ * Origin is refcounted and usually we keep the blob contents to be
+ * reused.
+ */
+static inline struct origin *origin_incref(struct origin *o)
+{
+	if (o)
+		o->refcnt++;
+	return o;
+}
+
+static void origin_decref(struct origin *o)
+{
+	if (o && --o->refcnt <= 0) {
+		if (o->previous)
+			origin_decref(o->previous);
+		free(o->file.ptr);
+		free(o);
+	}
+}
+
+static void drop_origin_blob(struct origin *o)
+{
+	if (o->file.ptr) {
+		free(o->file.ptr);
+		o->file.ptr = NULL;
+	}
+}
+
+/*
+ * Each group of lines is described by a blame_entry; it can be split
+ * as we pass blame to the parents.  They form a linked list in the
+ * scoreboard structure, sorted by the target line number.
+ */
+struct blame_entry {
+	struct blame_entry *prev;
+	struct blame_entry *next;
+
+	/* the first line of this group in the final image;
+	 * internally all line numbers are 0 based.
+	 */
+	int lno;
+
+	/* how many lines this group has */
+	int num_lines;
+
+	/* the commit that introduced this group into the final image */
+	struct origin *suspect;
+
+	/* true if the suspect is truly guilty; false while we have not
+	 * checked if the group came from one of its parents.
+	 */
+	char guilty;
+
+	/* true if the entry has been scanned for copies in the current parent
+	 */
+	char scanned;
+
+	/* the line number of the first line of this group in the
+	 * suspect's file; internally all line numbers are 0 based.
+	 */
+	int s_lno;
+
+	/* how significant this entry is -- cached to avoid
+	 * scanning the lines over and over.
+	 */
+	unsigned score;
+};
+
+/*
+ * The current state of the blame assignment.
+ */
+struct scoreboard {
+	/* the final commit (i.e. where we started digging from) */
+	struct commit *final;
+	struct rev_info *revs;
+	const char *path;
+
+	/*
+	 * The contents in the final image.
+	 * Used by many functions to obtain contents of the nth line,
+	 * indexed with scoreboard.lineno[blame_entry.lno].
+	 */
+	const char *final_buf;
+	unsigned long final_buf_size;
+
+	/* linked list of blames */
+	struct blame_entry *ent;
+
+	/* look-up a line in the final buffer */
+	int num_lines;
+	int *lineno;
+};
+
+static inline int same_suspect(struct origin *a, struct origin *b)
+{
+	if (a == b)
+		return 1;
+	if (a->commit != b->commit)
+		return 0;
+	return !strcmp(a->path, b->path);
+}
+
+static void sanity_check_refcnt(struct scoreboard *);
+
+/*
+ * If two blame entries that are next to each other came from
+ * contiguous lines in the same origin (i.e. <commit, path> pair),
+ * merge them together.
+ */
+static void coalesce(struct scoreboard *sb)
+{
+	struct blame_entry *ent, *next;
+
+	for (ent = sb->ent; ent && (next = ent->next); ent = next) {
+		if (same_suspect(ent->suspect, next->suspect) &&
+		    ent->guilty == next->guilty &&
+		    ent->s_lno + ent->num_lines == next->s_lno) {
+			ent->num_lines += next->num_lines;
+			ent->next = next->next;
+			if (ent->next)
+				ent->next->prev = ent;
+			origin_decref(next->suspect);
+			free(next);
+			ent->score = 0;
+			next = ent; /* again */
+		}
+	}
+
+	if (DEBUG) /* sanity */
+		sanity_check_refcnt(sb);
+}
+
+/*
+ * Given a commit and a path in it, create a new origin structure.
+ * The callers that add blame to the scoreboard should use
+ * get_origin() to obtain shared, refcounted copy instead of calling
+ * this function directly.
+ */
+static struct origin *make_origin(struct commit *commit, const char *path)
+{
+	struct origin *o;
+	o = xcalloc(1, sizeof(*o) + strlen(path) + 1);
+	o->commit = commit;
+	o->refcnt = 1;
+	strcpy(o->path, path);
+	return o;
+}
+
+/*
+ * Locate an existing origin or create a new one.
+ */
+static struct origin *get_origin(struct scoreboard *sb,
+				 struct commit *commit,
+				 const char *path)
+{
+	struct blame_entry *e;
+
+	for (e = sb->ent; e; e = e->next) {
+		if (e->suspect->commit == commit &&
+		    !strcmp(e->suspect->path, path))
+			return origin_incref(e->suspect);
+	}
+	return make_origin(commit, path);
+}
+
+/*
+ * Fill the blob_sha1 field of an origin if it hasn't, so that later
+ * call to fill_origin_blob() can use it to locate the data.  blob_sha1
+ * for an origin is also used to pass the blame for the entire file to
+ * the parent to detect the case where a child's blob is identical to
+ * that of its parent's.
+ */
+static int fill_blob_sha1(struct origin *origin)
+{
+	unsigned mode;
+
+	if (!is_null_sha1(origin->blob_sha1))
+		return 0;
+	if (get_tree_entry(origin->commit->object.sha1,
+			   origin->path,
+			   origin->blob_sha1, &mode))
+		goto error_out;
+	if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB)
+		goto error_out;
+	return 0;
+ error_out:
+	hashclr(origin->blob_sha1);
+	return -1;
+}
+
+/*
+ * We have an origin -- check if the same path exists in the
+ * parent and return an origin structure to represent it.
+ */
+static struct origin *find_origin(struct scoreboard *sb,
+				  struct commit *parent,
+				  struct origin *origin)
+{
+	struct origin *porigin = NULL;
+	struct diff_options diff_opts;
+	const char *paths[2];
+
+	if (parent->util) {
+		/*
+		 * Each commit object can cache one origin in that
+		 * commit.  This is a freestanding copy of origin and
+		 * not refcounted.
+		 */
+		struct origin *cached = parent->util;
+		if (!strcmp(cached->path, origin->path)) {
+			/*
+			 * The same path between origin and its parent
+			 * without renaming -- the most common case.
+			 */
+			porigin = get_origin(sb, parent, cached->path);
+
+			/*
+			 * If the origin was newly created (i.e. get_origin
+			 * would call make_origin if none is found in the
+			 * scoreboard), it does not know the blob_sha1,
+			 * so copy it.  Otherwise porigin was in the
+			 * scoreboard and already knows blob_sha1.
+			 */
+			if (porigin->refcnt == 1)
+				hashcpy(porigin->blob_sha1, cached->blob_sha1);
+			return porigin;
+		}
+		/* otherwise it was not very useful; free it */
+		free(parent->util);
+		parent->util = NULL;
+	}
+
+	/* See if the origin->path is different between parent
+	 * and origin first.  Most of the time they are the
+	 * same and diff-tree is fairly efficient about this.
+	 */
+	diff_setup(&diff_opts);
+	DIFF_OPT_SET(&diff_opts, RECURSIVE);
+	diff_opts.detect_rename = 0;
+	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
+	paths[0] = origin->path;
+	paths[1] = NULL;
+
+	diff_tree_setup_paths(paths, &diff_opts);
+	if (diff_setup_done(&diff_opts) < 0)
+		die("diff-setup");
+
+	if (is_null_sha1(origin->commit->object.sha1))
+		do_diff_cache(parent->tree->object.sha1, &diff_opts);
+	else
+		diff_tree_sha1(parent->tree->object.sha1,
+			       origin->commit->tree->object.sha1,
+			       "", &diff_opts);
+	diffcore_std(&diff_opts);
+
+	if (!diff_queued_diff.nr) {
+		/* The path is the same as parent */
+		porigin = get_origin(sb, parent, origin->path);
+		hashcpy(porigin->blob_sha1, origin->blob_sha1);
+	} else {
+		/*
+		 * Since origin->path is a pathspec, if the parent
+		 * commit had it as a directory, we will see a whole
+		 * bunch of deletion of files in the directory that we
+		 * do not care about.
+		 */
+		int i;
+		struct diff_filepair *p = NULL;
+		for (i = 0; i < diff_queued_diff.nr; i++) {
+			const char *name;
+			p = diff_queued_diff.queue[i];
+			name = p->one->path ? p->one->path : p->two->path;
+			if (!strcmp(name, origin->path))
+				break;
+		}
+		if (!p)
+			die("internal error in blame::find_origin");
+		switch (p->status) {
+		default:
+			die("internal error in blame::find_origin (%c)",
+			    p->status);
+		case 'M':
+			porigin = get_origin(sb, parent, origin->path);
+			hashcpy(porigin->blob_sha1, p->one->sha1);
+			break;
+		case 'A':
+		case 'T':
+			/* Did not exist in parent, or type changed */
+			break;
+		}
+	}
+	diff_flush(&diff_opts);
+	diff_tree_release_paths(&diff_opts);
+	if (porigin) {
+		/*
+		 * Create a freestanding copy that is not part of
+		 * the refcounted origin found in the scoreboard, and
+		 * cache it in the commit.
+		 */
+		struct origin *cached;
+
+		cached = make_origin(porigin->commit, porigin->path);
+		hashcpy(cached->blob_sha1, porigin->blob_sha1);
+		parent->util = cached;
+	}
+	return porigin;
+}
+
+/*
+ * We have an origin -- find the path that corresponds to it in its
+ * parent and return an origin structure to represent it.
+ */
+static struct origin *find_rename(struct scoreboard *sb,
+				  struct commit *parent,
+				  struct origin *origin)
+{
+	struct origin *porigin = NULL;
+	struct diff_options diff_opts;
+	int i;
+	const char *paths[2];
+
+	diff_setup(&diff_opts);
+	DIFF_OPT_SET(&diff_opts, RECURSIVE);
+	diff_opts.detect_rename = DIFF_DETECT_RENAME;
+	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
+	diff_opts.single_follow = origin->path;
+	paths[0] = NULL;
+	diff_tree_setup_paths(paths, &diff_opts);
+	if (diff_setup_done(&diff_opts) < 0)
+		die("diff-setup");
+
+	if (is_null_sha1(origin->commit->object.sha1))
+		do_diff_cache(parent->tree->object.sha1, &diff_opts);
+	else
+		diff_tree_sha1(parent->tree->object.sha1,
+			       origin->commit->tree->object.sha1,
+			       "", &diff_opts);
+	diffcore_std(&diff_opts);
+
+	for (i = 0; i < diff_queued_diff.nr; i++) {
+		struct diff_filepair *p = diff_queued_diff.queue[i];
+		if ((p->status == 'R' || p->status == 'C') &&
+		    !strcmp(p->two->path, origin->path)) {
+			porigin = get_origin(sb, parent, p->one->path);
+			hashcpy(porigin->blob_sha1, p->one->sha1);
+			break;
+		}
+	}
+	diff_flush(&diff_opts);
+	diff_tree_release_paths(&diff_opts);
+	return porigin;
+}
+
+/*
+ * Link in a new blame entry to the scoreboard.  Entries that cover the
+ * same line range have been removed from the scoreboard previously.
+ */
+static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e)
+{
+	struct blame_entry *ent, *prev = NULL;
+
+	origin_incref(e->suspect);
+
+	for (ent = sb->ent; ent && ent->lno < e->lno; ent = ent->next)
+		prev = ent;
+
+	/* prev, if not NULL, is the last one that is below e */
+	e->prev = prev;
+	if (prev) {
+		e->next = prev->next;
+		prev->next = e;
+	}
+	else {
+		e->next = sb->ent;
+		sb->ent = e;
+	}
+	if (e->next)
+		e->next->prev = e;
+}
+
+/*
+ * src typically is on-stack; we want to copy the information in it to
+ * a malloced blame_entry that is already on the linked list of the
+ * scoreboard.  The origin of dst loses a refcnt while the origin of src
+ * gains one.
+ */
+static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
+{
+	struct blame_entry *p, *n;
+
+	p = dst->prev;
+	n = dst->next;
+	origin_incref(src->suspect);
+	origin_decref(dst->suspect);
+	memcpy(dst, src, sizeof(*src));
+	dst->prev = p;
+	dst->next = n;
+	dst->score = 0;
+}
+
+static const char *nth_line(struct scoreboard *sb, int lno)
+{
+	return sb->final_buf + sb->lineno[lno];
+}
+
+/*
+ * It is known that lines between tlno to same came from parent, and e
+ * has an overlap with that range.  it also is known that parent's
+ * line plno corresponds to e's line tlno.
+ *
+ *                <---- e ----->
+ *                   <------>
+ *                   <------------>
+ *             <------------>
+ *             <------------------>
+ *
+ * Split e into potentially three parts; before this chunk, the chunk
+ * to be blamed for the parent, and after that portion.
+ */
+static void split_overlap(struct blame_entry *split,
+			  struct blame_entry *e,
+			  int tlno, int plno, int same,
+			  struct origin *parent)
+{
+	int chunk_end_lno;
+	memset(split, 0, sizeof(struct blame_entry [3]));
+
+	if (e->s_lno < tlno) {
+		/* there is a pre-chunk part not blamed on parent */
+		split[0].suspect = origin_incref(e->suspect);
+		split[0].lno = e->lno;
+		split[0].s_lno = e->s_lno;
+		split[0].num_lines = tlno - e->s_lno;
+		split[1].lno = e->lno + tlno - e->s_lno;
+		split[1].s_lno = plno;
+	}
+	else {
+		split[1].lno = e->lno;
+		split[1].s_lno = plno + (e->s_lno - tlno);
+	}
+
+	if (same < e->s_lno + e->num_lines) {
+		/* there is a post-chunk part not blamed on parent */
+		split[2].suspect = origin_incref(e->suspect);
+		split[2].lno = e->lno + (same - e->s_lno);
+		split[2].s_lno = e->s_lno + (same - e->s_lno);
+		split[2].num_lines = e->s_lno + e->num_lines - same;
+		chunk_end_lno = split[2].lno;
+	}
+	else
+		chunk_end_lno = e->lno + e->num_lines;
+	split[1].num_lines = chunk_end_lno - split[1].lno;
+
+	/*
+	 * if it turns out there is nothing to blame the parent for,
+	 * forget about the splitting.  !split[1].suspect signals this.
+	 */
+	if (split[1].num_lines < 1)
+		return;
+	split[1].suspect = origin_incref(parent);
+}
+
+/*
+ * split_overlap() divided an existing blame e into up to three parts
+ * in split.  Adjust the linked list of blames in the scoreboard to
+ * reflect the split.
+ */
+static void split_blame(struct scoreboard *sb,
+			struct blame_entry *split,
+			struct blame_entry *e)
+{
+	struct blame_entry *new_entry;
+
+	if (split[0].suspect && split[2].suspect) {
+		/* The first part (reuse storage for the existing entry e) */
+		dup_entry(e, &split[0]);
+
+		/* The last part -- me */
+		new_entry = xmalloc(sizeof(*new_entry));
+		memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
+		add_blame_entry(sb, new_entry);
+
+		/* ... and the middle part -- parent */
+		new_entry = xmalloc(sizeof(*new_entry));
+		memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
+		add_blame_entry(sb, new_entry);
+	}
+	else if (!split[0].suspect && !split[2].suspect)
+		/*
+		 * The parent covers the entire area; reuse storage for
+		 * e and replace it with the parent.
+		 */
+		dup_entry(e, &split[1]);
+	else if (split[0].suspect) {
+		/* me and then parent */
+		dup_entry(e, &split[0]);
+
+		new_entry = xmalloc(sizeof(*new_entry));
+		memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
+		add_blame_entry(sb, new_entry);
+	}
+	else {
+		/* parent and then me */
+		dup_entry(e, &split[1]);
+
+		new_entry = xmalloc(sizeof(*new_entry));
+		memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
+		add_blame_entry(sb, new_entry);
+	}
+
+	if (DEBUG) { /* sanity */
+		struct blame_entry *ent;
+		int lno = sb->ent->lno, corrupt = 0;
+
+		for (ent = sb->ent; ent; ent = ent->next) {
+			if (lno != ent->lno)
+				corrupt = 1;
+			if (ent->s_lno < 0)
+				corrupt = 1;
+			lno += ent->num_lines;
+		}
+		if (corrupt) {
+			lno = sb->ent->lno;
+			for (ent = sb->ent; ent; ent = ent->next) {
+				printf("L %8d l %8d n %8d\n",
+				       lno, ent->lno, ent->num_lines);
+				lno = ent->lno + ent->num_lines;
+			}
+			die("oops");
+		}
+	}
+}
+
+/*
+ * After splitting the blame, the origins used by the
+ * on-stack blame_entry should lose one refcnt each.
+ */
+static void decref_split(struct blame_entry *split)
+{
+	int i;
+
+	for (i = 0; i < 3; i++)
+		origin_decref(split[i].suspect);
+}
+
+/*
+ * Helper for blame_chunk().  blame_entry e is known to overlap with
+ * the patch hunk; split it and pass blame to the parent.
+ */
+static void blame_overlap(struct scoreboard *sb, struct blame_entry *e,
+			  int tlno, int plno, int same,
+			  struct origin *parent)
+{
+	struct blame_entry split[3];
+
+	split_overlap(split, e, tlno, plno, same, parent);
+	if (split[1].suspect)
+		split_blame(sb, split, e);
+	decref_split(split);
+}
+
+/*
+ * Find the line number of the last line the target is suspected for.
+ */
+static int find_last_in_target(struct scoreboard *sb, struct origin *target)
+{
+	struct blame_entry *e;
+	int last_in_target = -1;
+
+	for (e = sb->ent; e; e = e->next) {
+		if (e->guilty || !same_suspect(e->suspect, target))
+			continue;
+		if (last_in_target < e->s_lno + e->num_lines)
+			last_in_target = e->s_lno + e->num_lines;
+	}
+	return last_in_target;
+}
+
+/*
+ * Process one hunk from the patch between the current suspect for
+ * blame_entry e and its parent.  Find and split the overlap, and
+ * pass blame to the overlapping part to the parent.
+ */
+static void blame_chunk(struct scoreboard *sb,
+			int tlno, int plno, int same,
+			struct origin *target, struct origin *parent)
+{
+	struct blame_entry *e;
+
+	for (e = sb->ent; e; e = e->next) {
+		if (e->guilty || !same_suspect(e->suspect, target))
+			continue;
+		if (same <= e->s_lno)
+			continue;
+		if (tlno < e->s_lno + e->num_lines)
+			blame_overlap(sb, e, tlno, plno, same, parent);
+	}
+}
+
+struct blame_chunk_cb_data {
+	struct scoreboard *sb;
+	struct origin *target;
+	struct origin *parent;
+	long plno;
+	long tlno;
+};
+
+static void blame_chunk_cb(void *data, long same, long p_next, long t_next)
+{
+	struct blame_chunk_cb_data *d = data;
+	blame_chunk(d->sb, d->tlno, d->plno, same, d->target, d->parent);
+	d->plno = p_next;
+	d->tlno = t_next;
+}
+
+/*
+ * We are looking at the origin 'target' and aiming to pass blame
+ * for the lines it is suspected to its parent.  Run diff to find
+ * which lines came from parent and pass blame for them.
+ */
+static int pass_blame_to_parent(struct scoreboard *sb,
+				struct origin *target,
+				struct origin *parent)
+{
+	int last_in_target;
+	mmfile_t file_p, file_o;
+	struct blame_chunk_cb_data d = { sb, target, parent, 0, 0 };
+	xpparam_t xpp;
+	xdemitconf_t xecfg;
+
+	last_in_target = find_last_in_target(sb, target);
+	if (last_in_target < 0)
+		return 1; /* nothing remains for this target */
+
+	fill_origin_blob(parent, &file_p);
+	fill_origin_blob(target, &file_o);
+	num_get_patch++;
+
+	memset(&xpp, 0, sizeof(xpp));
+	xpp.flags = xdl_opts;
+	memset(&xecfg, 0, sizeof(xecfg));
+	xecfg.ctxlen = 0;
+	xdi_diff_hunks(&file_p, &file_o, blame_chunk_cb, &d, &xpp, &xecfg);
+	/* The rest (i.e. anything after tlno) are the same as the parent */
+	blame_chunk(sb, d.tlno, d.plno, last_in_target, target, parent);
+
+	return 0;
+}
+
+/*
+ * The lines in blame_entry after splitting blames many times can become
+ * very small and trivial, and at some point it becomes pointless to
+ * blame the parents.  E.g. "\t\t}\n\t}\n\n" appears everywhere in any
+ * ordinary C program, and it is not worth to say it was copied from
+ * totally unrelated file in the parent.
+ *
+ * Compute how trivial the lines in the blame_entry are.
+ */
+static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
+{
+	unsigned score;
+	const char *cp, *ep;
+
+	if (e->score)
+		return e->score;
+
+	score = 1;
+	cp = nth_line(sb, e->lno);
+	ep = nth_line(sb, e->lno + e->num_lines);
+	while (cp < ep) {
+		unsigned ch = *((unsigned char *)cp);
+		if (isalnum(ch))
+			score++;
+		cp++;
+	}
+	e->score = score;
+	return score;
+}
+
+/*
+ * best_so_far[] and this[] are both a split of an existing blame_entry
+ * that passes blame to the parent.  Maintain best_so_far the best split
+ * so far, by comparing this and best_so_far and copying this into
+ * bst_so_far as needed.
+ */
+static void copy_split_if_better(struct scoreboard *sb,
+				 struct blame_entry *best_so_far,
+				 struct blame_entry *this)
+{
+	int i;
+
+	if (!this[1].suspect)
+		return;
+	if (best_so_far[1].suspect) {
+		if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
+			return;
+	}
+
+	for (i = 0; i < 3; i++)
+		origin_incref(this[i].suspect);
+	decref_split(best_so_far);
+	memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
+}
+
+/*
+ * We are looking at a part of the final image represented by
+ * ent (tlno and same are offset by ent->s_lno).
+ * tlno is where we are looking at in the final image.
+ * up to (but not including) same match preimage.
+ * plno is where we are looking at in the preimage.
+ *
+ * <-------------- final image ---------------------->
+ *       <------ent------>
+ *         ^tlno ^same
+ *    <---------preimage----->
+ *         ^plno
+ *
+ * All line numbers are 0-based.
+ */
+static void handle_split(struct scoreboard *sb,
+			 struct blame_entry *ent,
+			 int tlno, int plno, int same,
+			 struct origin *parent,
+			 struct blame_entry *split)
+{
+	if (ent->num_lines <= tlno)
+		return;
+	if (tlno < same) {
+		struct blame_entry this[3];
+		tlno += ent->s_lno;
+		same += ent->s_lno;
+		split_overlap(this, ent, tlno, plno, same, parent);
+		copy_split_if_better(sb, split, this);
+		decref_split(this);
+	}
+}
+
+struct handle_split_cb_data {
+	struct scoreboard *sb;
+	struct blame_entry *ent;
+	struct origin *parent;
+	struct blame_entry *split;
+	long plno;
+	long tlno;
+};
+
+static void handle_split_cb(void *data, long same, long p_next, long t_next)
+{
+	struct handle_split_cb_data *d = data;
+	handle_split(d->sb, d->ent, d->tlno, d->plno, same, d->parent, d->split);
+	d->plno = p_next;
+	d->tlno = t_next;
+}
+
+/*
+ * Find the lines from parent that are the same as ent so that
+ * we can pass blames to it.  file_p has the blob contents for
+ * the parent.
+ */
+static void find_copy_in_blob(struct scoreboard *sb,
+			      struct blame_entry *ent,
+			      struct origin *parent,
+			      struct blame_entry *split,
+			      mmfile_t *file_p)
+{
+	const char *cp;
+	int cnt;
+	mmfile_t file_o;
+	struct handle_split_cb_data d = { sb, ent, parent, split, 0, 0 };
+	xpparam_t xpp;
+	xdemitconf_t xecfg;
+
+	/*
+	 * Prepare mmfile that contains only the lines in ent.
+	 */
+	cp = nth_line(sb, ent->lno);
+	file_o.ptr = (char *) cp;
+	cnt = ent->num_lines;
+
+	while (cnt && cp < sb->final_buf + sb->final_buf_size) {
+		if (*cp++ == '\n')
+			cnt--;
+	}
+	file_o.size = cp - file_o.ptr;
+
+	/*
+	 * file_o is a part of final image we are annotating.
+	 * file_p partially may match that image.
+	 */
+	memset(&xpp, 0, sizeof(xpp));
+	xpp.flags = xdl_opts;
+	memset(&xecfg, 0, sizeof(xecfg));
+	xecfg.ctxlen = 1;
+	memset(split, 0, sizeof(struct blame_entry [3]));
+	xdi_diff_hunks(file_p, &file_o, handle_split_cb, &d, &xpp, &xecfg);
+	/* remainder, if any, all match the preimage */
+	handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
+}
+
+/*
+ * See if lines currently target is suspected for can be attributed to
+ * parent.
+ */
+static int find_move_in_parent(struct scoreboard *sb,
+			       struct origin *target,
+			       struct origin *parent)
+{
+	int last_in_target, made_progress;
+	struct blame_entry *e, split[3];
+	mmfile_t file_p;
+
+	last_in_target = find_last_in_target(sb, target);
+	if (last_in_target < 0)
+		return 1; /* nothing remains for this target */
+
+	fill_origin_blob(parent, &file_p);
+	if (!file_p.ptr)
+		return 0;
+
+	made_progress = 1;
+	while (made_progress) {
+		made_progress = 0;
+		for (e = sb->ent; e; e = e->next) {
+			if (e->guilty || !same_suspect(e->suspect, target) ||
+			    ent_score(sb, e) < blame_move_score)
+				continue;
+			find_copy_in_blob(sb, e, parent, split, &file_p);
+			if (split[1].suspect &&
+			    blame_move_score < ent_score(sb, &split[1])) {
+				split_blame(sb, split, e);
+				made_progress = 1;
+			}
+			decref_split(split);
+		}
+	}
+	return 0;
+}
+
+struct blame_list {
+	struct blame_entry *ent;
+	struct blame_entry split[3];
+};
+
+/*
+ * Count the number of entries the target is suspected for,
+ * and prepare a list of entry and the best split.
+ */
+static struct blame_list *setup_blame_list(struct scoreboard *sb,
+					   struct origin *target,
+					   int min_score,
+					   int *num_ents_p)
+{
+	struct blame_entry *e;
+	int num_ents, i;
+	struct blame_list *blame_list = NULL;
+
+	for (e = sb->ent, num_ents = 0; e; e = e->next)
+		if (!e->scanned && !e->guilty &&
+		    same_suspect(e->suspect, target) &&
+		    min_score < ent_score(sb, e))
+			num_ents++;
+	if (num_ents) {
+		blame_list = xcalloc(num_ents, sizeof(struct blame_list));
+		for (e = sb->ent, i = 0; e; e = e->next)
+			if (!e->scanned && !e->guilty &&
+			    same_suspect(e->suspect, target) &&
+			    min_score < ent_score(sb, e))
+				blame_list[i++].ent = e;
+	}
+	*num_ents_p = num_ents;
+	return blame_list;
+}
+
+/*
+ * Reset the scanned status on all entries.
+ */
+static void reset_scanned_flag(struct scoreboard *sb)
+{
+	struct blame_entry *e;
+	for (e = sb->ent; e; e = e->next)
+		e->scanned = 0;
+}
+
+/*
+ * For lines target is suspected for, see if we can find code movement
+ * across file boundary from the parent commit.  porigin is the path
+ * in the parent we already tried.
+ */
+static int find_copy_in_parent(struct scoreboard *sb,
+			       struct origin *target,
+			       struct commit *parent,
+			       struct origin *porigin,
+			       int opt)
+{
+	struct diff_options diff_opts;
+	const char *paths[1];
+	int i, j;
+	int retval;
+	struct blame_list *blame_list;
+	int num_ents;
+
+	blame_list = setup_blame_list(sb, target, blame_copy_score, &num_ents);
+	if (!blame_list)
+		return 1; /* nothing remains for this target */
+
+	diff_setup(&diff_opts);
+	DIFF_OPT_SET(&diff_opts, RECURSIVE);
+	diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
+
+	paths[0] = NULL;
+	diff_tree_setup_paths(paths, &diff_opts);
+	if (diff_setup_done(&diff_opts) < 0)
+		die("diff-setup");
+
+	/* Try "find copies harder" on new path if requested;
+	 * we do not want to use diffcore_rename() actually to
+	 * match things up; find_copies_harder is set only to
+	 * force diff_tree_sha1() to feed all filepairs to diff_queue,
+	 * and this code needs to be after diff_setup_done(), which
+	 * usually makes find-copies-harder imply copy detection.
+	 */
+	if ((opt & PICKAXE_BLAME_COPY_HARDEST)
+	    || ((opt & PICKAXE_BLAME_COPY_HARDER)
+		&& (!porigin || strcmp(target->path, porigin->path))))
+		DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
+
+	if (is_null_sha1(target->commit->object.sha1))
+		do_diff_cache(parent->tree->object.sha1, &diff_opts);
+	else
+		diff_tree_sha1(parent->tree->object.sha1,
+			       target->commit->tree->object.sha1,
+			       "", &diff_opts);
+
+	if (!DIFF_OPT_TST(&diff_opts, FIND_COPIES_HARDER))
+		diffcore_std(&diff_opts);
+
+	retval = 0;
+	while (1) {
+		int made_progress = 0;
+
+		for (i = 0; i < diff_queued_diff.nr; i++) {
+			struct diff_filepair *p = diff_queued_diff.queue[i];
+			struct origin *norigin;
+			mmfile_t file_p;
+			struct blame_entry this[3];
+
+			if (!DIFF_FILE_VALID(p->one))
+				continue; /* does not exist in parent */
+			if (S_ISGITLINK(p->one->mode))
+				continue; /* ignore git links */
+			if (porigin && !strcmp(p->one->path, porigin->path))
+				/* find_move already dealt with this path */
+				continue;
+
+			norigin = get_origin(sb, parent, p->one->path);
+			hashcpy(norigin->blob_sha1, p->one->sha1);
+			fill_origin_blob(norigin, &file_p);
+			if (!file_p.ptr)
+				continue;
+
+			for (j = 0; j < num_ents; j++) {
+				find_copy_in_blob(sb, blame_list[j].ent,
+						  norigin, this, &file_p);
+				copy_split_if_better(sb, blame_list[j].split,
+						     this);
+				decref_split(this);
+			}
+			origin_decref(norigin);
+		}
+
+		for (j = 0; j < num_ents; j++) {
+			struct blame_entry *split = blame_list[j].split;
+			if (split[1].suspect &&
+			    blame_copy_score < ent_score(sb, &split[1])) {
+				split_blame(sb, split, blame_list[j].ent);
+				made_progress = 1;
+			}
+			else
+				blame_list[j].ent->scanned = 1;
+			decref_split(split);
+		}
+		free(blame_list);
+
+		if (!made_progress)
+			break;
+		blame_list = setup_blame_list(sb, target, blame_copy_score, &num_ents);
+		if (!blame_list) {
+			retval = 1;
+			break;
+		}
+	}
+	reset_scanned_flag(sb);
+	diff_flush(&diff_opts);
+	diff_tree_release_paths(&diff_opts);
+	return retval;
+}
+
+/*
+ * The blobs of origin and porigin exactly match, so everything
+ * origin is suspected for can be blamed on the parent.
+ */
+static void pass_whole_blame(struct scoreboard *sb,
+			     struct origin *origin, struct origin *porigin)
+{
+	struct blame_entry *e;
+
+	if (!porigin->file.ptr && origin->file.ptr) {
+		/* Steal its file */
+		porigin->file = origin->file;
+		origin->file.ptr = NULL;
+	}
+	for (e = sb->ent; e; e = e->next) {
+		if (!same_suspect(e->suspect, origin))
+			continue;
+		origin_incref(porigin);
+		origin_decref(e->suspect);
+		e->suspect = porigin;
+	}
+}
+
+/*
+ * We pass blame from the current commit to its parents.  We keep saying
+ * "parent" (and "porigin"), but what we mean is to find scapegoat to
+ * exonerate ourselves.
+ */
+static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit)
+{
+	if (!reverse)
+		return commit->parents;
+	return lookup_decoration(&revs->children, &commit->object);
+}
+
+static int num_scapegoats(struct rev_info *revs, struct commit *commit)
+{
+	int cnt;
+	struct commit_list *l = first_scapegoat(revs, commit);
+	for (cnt = 0; l; l = l->next)
+		cnt++;
+	return cnt;
+}
+
+#define MAXSG 16
+
+static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
+{
+	struct rev_info *revs = sb->revs;
+	int i, pass, num_sg;
+	struct commit *commit = origin->commit;
+	struct commit_list *sg;
+	struct origin *sg_buf[MAXSG];
+	struct origin *porigin, **sg_origin = sg_buf;
+
+	num_sg = num_scapegoats(revs, commit);
+	if (!num_sg)
+		goto finish;
+	else if (num_sg < ARRAY_SIZE(sg_buf))
+		memset(sg_buf, 0, sizeof(sg_buf));
+	else
+		sg_origin = xcalloc(num_sg, sizeof(*sg_origin));
+
+	/*
+	 * The first pass looks for unrenamed path to optimize for
+	 * common cases, then we look for renames in the second pass.
+	 */
+	for (pass = 0; pass < 2; pass++) {
+		struct origin *(*find)(struct scoreboard *,
+				       struct commit *, struct origin *);
+		find = pass ? find_rename : find_origin;
+
+		for (i = 0, sg = first_scapegoat(revs, commit);
+		     i < num_sg && sg;
+		     sg = sg->next, i++) {
+			struct commit *p = sg->item;
+			int j, same;
+
+			if (sg_origin[i])
+				continue;
+			if (parse_commit(p))
+				continue;
+			porigin = find(sb, p, origin);
+			if (!porigin)
+				continue;
+			if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) {
+				pass_whole_blame(sb, origin, porigin);
+				origin_decref(porigin);
+				goto finish;
+			}
+			for (j = same = 0; j < i; j++)
+				if (sg_origin[j] &&
+				    !hashcmp(sg_origin[j]->blob_sha1,
+					     porigin->blob_sha1)) {
+					same = 1;
+					break;
+				}
+			if (!same)
+				sg_origin[i] = porigin;
+			else
+				origin_decref(porigin);
+		}
+	}
+
+	num_commits++;
+	for (i = 0, sg = first_scapegoat(revs, commit);
+	     i < num_sg && sg;
+	     sg = sg->next, i++) {
+		struct origin *porigin = sg_origin[i];
+		if (!porigin)
+			continue;
+		if (!origin->previous) {
+			origin_incref(porigin);
+			origin->previous = porigin;
+		}
+		if (pass_blame_to_parent(sb, origin, porigin))
+			goto finish;
+	}
+
+	/*
+	 * Optionally find moves in parents' files.
+	 */
+	if (opt & PICKAXE_BLAME_MOVE)
+		for (i = 0, sg = first_scapegoat(revs, commit);
+		     i < num_sg && sg;
+		     sg = sg->next, i++) {
+			struct origin *porigin = sg_origin[i];
+			if (!porigin)
+				continue;
+			if (find_move_in_parent(sb, origin, porigin))
+				goto finish;
+		}
+
+	/*
+	 * Optionally find copies from parents' files.
+	 */
+	if (opt & PICKAXE_BLAME_COPY)
+		for (i = 0, sg = first_scapegoat(revs, commit);
+		     i < num_sg && sg;
+		     sg = sg->next, i++) {
+			struct origin *porigin = sg_origin[i];
+			if (find_copy_in_parent(sb, origin, sg->item,
+						porigin, opt))
+				goto finish;
+		}
+
+ finish:
+	for (i = 0; i < num_sg; i++) {
+		if (sg_origin[i]) {
+			drop_origin_blob(sg_origin[i]);
+			origin_decref(sg_origin[i]);
+		}
+	}
+	drop_origin_blob(origin);
+	if (sg_buf != sg_origin)
+		free(sg_origin);
+}
+
+/*
+ * Information on commits, used for output.
+ */
+struct commit_info
+{
+	const char *author;
+	const char *author_mail;
+	unsigned long author_time;
+	const char *author_tz;
+
+	/* filled only when asked for details */
+	const char *committer;
+	const char *committer_mail;
+	unsigned long committer_time;
+	const char *committer_tz;
+
+	const char *summary;
+};
+
+/*
+ * Parse author/committer line in the commit object buffer
+ */
+static void get_ac_line(const char *inbuf, const char *what,
+			int person_len, char *person,
+			int mail_len, char *mail,
+			unsigned long *time, const char **tz)
+{
+	int len, tzlen, maillen;
+	char *tmp, *endp, *timepos, *mailpos;
+
+	tmp = strstr(inbuf, what);
+	if (!tmp)
+		goto error_out;
+	tmp += strlen(what);
+	endp = strchr(tmp, '\n');
+	if (!endp)
+		len = strlen(tmp);
+	else
+		len = endp - tmp;
+	if (person_len <= len) {
+	error_out:
+		/* Ugh */
+		*tz = "(unknown)";
+		strcpy(person, *tz);
+		strcpy(mail, *tz);
+		*time = 0;
+		return;
+	}
+	memcpy(person, tmp, len);
+
+	tmp = person;
+	tmp += len;
+	*tmp = 0;
+	while (person < tmp && *tmp != ' ')
+		tmp--;
+	if (tmp <= person)
+		goto error_out;
+	*tz = tmp+1;
+	tzlen = (person+len)-(tmp+1);
+
+	*tmp = 0;
+	while (person < tmp && *tmp != ' ')
+		tmp--;
+	if (tmp <= person)
+		goto error_out;
+	*time = strtoul(tmp, NULL, 10);
+	timepos = tmp;
+
+	*tmp = 0;
+	while (person < tmp && *tmp != ' ')
+		tmp--;
+	if (tmp <= person)
+		return;
+	mailpos = tmp + 1;
+	*tmp = 0;
+	maillen = timepos - tmp;
+	memcpy(mail, mailpos, maillen);
+
+	if (!mailmap.nr)
+		return;
+
+	/*
+	 * mailmap expansion may make the name longer.
+	 * make room by pushing stuff down.
+	 */
+	tmp = person + person_len - (tzlen + 1);
+	memmove(tmp, *tz, tzlen);
+	tmp[tzlen] = 0;
+	*tz = tmp;
+
+	/*
+	 * Now, convert both name and e-mail using mailmap
+	 */
+	if (map_user(&mailmap, mail+1, mail_len-1, person, tmp-person-1)) {
+		/* Add a trailing '>' to email, since map_user returns plain emails
+		   Note: It already has '<', since we replace from mail+1 */
+		mailpos = memchr(mail, '\0', mail_len);
+		if (mailpos && mailpos-mail < mail_len - 1) {
+			*mailpos = '>';
+			*(mailpos+1) = '\0';
+		}
+	}
+}
+
+static void get_commit_info(struct commit *commit,
+			    struct commit_info *ret,
+			    int detailed)
+{
+	int len;
+	char *tmp, *endp, *reencoded, *message;
+	static char author_name[1024];
+	static char author_mail[1024];
+	static char committer_name[1024];
+	static char committer_mail[1024];
+	static char summary_buf[1024];
+
+	/*
+	 * We've operated without save_commit_buffer, so
+	 * we now need to populate them for output.
+	 */
+	if (!commit->buffer) {
+		enum object_type type;
+		unsigned long size;
+		commit->buffer =
+			read_sha1_file(commit->object.sha1, &type, &size);
+		if (!commit->buffer)
+			die("Cannot read commit %s",
+			    sha1_to_hex(commit->object.sha1));
+	}
+	reencoded = reencode_commit_message(commit, NULL);
+	message   = reencoded ? reencoded : commit->buffer;
+	ret->author = author_name;
+	ret->author_mail = author_mail;
+	get_ac_line(message, "\nauthor ",
+		    sizeof(author_name), author_name,
+		    sizeof(author_mail), author_mail,
+		    &ret->author_time, &ret->author_tz);
+
+	if (!detailed) {
+		free(reencoded);
+		return;
+	}
+
+	ret->committer = committer_name;
+	ret->committer_mail = committer_mail;
+	get_ac_line(message, "\ncommitter ",
+		    sizeof(committer_name), committer_name,
+		    sizeof(committer_mail), committer_mail,
+		    &ret->committer_time, &ret->committer_tz);
+
+	ret->summary = summary_buf;
+	tmp = strstr(message, "\n\n");
+	if (!tmp) {
+	error_out:
+		sprintf(summary_buf, "(%s)", sha1_to_hex(commit->object.sha1));
+		free(reencoded);
+		return;
+	}
+	tmp += 2;
+	endp = strchr(tmp, '\n');
+	if (!endp)
+		endp = tmp + strlen(tmp);
+	len = endp - tmp;
+	if (len >= sizeof(summary_buf) || len == 0)
+		goto error_out;
+	memcpy(summary_buf, tmp, len);
+	summary_buf[len] = 0;
+	free(reencoded);
+}
+
+/*
+ * To allow LF and other nonportable characters in pathnames,
+ * they are c-style quoted as needed.
+ */
+static void write_filename_info(const char *path)
+{
+	printf("filename ");
+	write_name_quoted(path, stdout, '\n');
+}
+
+/*
+ * Porcelain/Incremental format wants to show a lot of details per
+ * commit.  Instead of repeating this every line, emit it only once,
+ * the first time each commit appears in the output.
+ */
+static int emit_one_suspect_detail(struct origin *suspect)
+{
+	struct commit_info ci;
+
+	if (suspect->commit->object.flags & METAINFO_SHOWN)
+		return 0;
+
+	suspect->commit->object.flags |= METAINFO_SHOWN;
+	get_commit_info(suspect->commit, &ci, 1);
+	printf("author %s\n", ci.author);
+	printf("author-mail %s\n", ci.author_mail);
+	printf("author-time %lu\n", ci.author_time);
+	printf("author-tz %s\n", ci.author_tz);
+	printf("committer %s\n", ci.committer);
+	printf("committer-mail %s\n", ci.committer_mail);
+	printf("committer-time %lu\n", ci.committer_time);
+	printf("committer-tz %s\n", ci.committer_tz);
+	printf("summary %s\n", ci.summary);
+	if (suspect->commit->object.flags & UNINTERESTING)
+		printf("boundary\n");
+	if (suspect->previous) {
+		struct origin *prev = suspect->previous;
+		printf("previous %s ", sha1_to_hex(prev->commit->object.sha1));
+		write_name_quoted(prev->path, stdout, '\n');
+	}
+	return 1;
+}
+
+/*
+ * The blame_entry is found to be guilty for the range.  Mark it
+ * as such, and show it in incremental output.
+ */
+static void found_guilty_entry(struct blame_entry *ent)
+{
+	if (ent->guilty)
+		return;
+	ent->guilty = 1;
+	if (incremental) {
+		struct origin *suspect = ent->suspect;
+
+		printf("%s %d %d %d\n",
+		       sha1_to_hex(suspect->commit->object.sha1),
+		       ent->s_lno + 1, ent->lno + 1, ent->num_lines);
+		emit_one_suspect_detail(suspect);
+		write_filename_info(suspect->path);
+		maybe_flush_or_die(stdout, "stdout");
+	}
+}
+
+/*
+ * The main loop -- while the scoreboard has lines whose true origin
+ * is still unknown, pick one blame_entry, and allow its current
+ * suspect to pass blames to its parents.
+ */
+static void assign_blame(struct scoreboard *sb, int opt)
+{
+	struct rev_info *revs = sb->revs;
+
+	while (1) {
+		struct blame_entry *ent;
+		struct commit *commit;
+		struct origin *suspect = NULL;
+
+		/* find one suspect to break down */
+		for (ent = sb->ent; !suspect && ent; ent = ent->next)
+			if (!ent->guilty)
+				suspect = ent->suspect;
+		if (!suspect)
+			return; /* all done */
+
+		/*
+		 * We will use this suspect later in the loop,
+		 * so hold onto it in the meantime.
+		 */
+		origin_incref(suspect);
+		commit = suspect->commit;
+		if (!commit->object.parsed)
+			parse_commit(commit);
+		if (reverse ||
+		    (!(commit->object.flags & UNINTERESTING) &&
+		     !(revs->max_age != -1 && commit->date < revs->max_age)))
+			pass_blame(sb, suspect, opt);
+		else {
+			commit->object.flags |= UNINTERESTING;
+			if (commit->object.parsed)
+				mark_parents_uninteresting(commit);
+		}
+		/* treat root commit as boundary */
+		if (!commit->parents && !show_root)
+			commit->object.flags |= UNINTERESTING;
+
+		/* Take responsibility for the remaining entries */
+		for (ent = sb->ent; ent; ent = ent->next)
+			if (same_suspect(ent->suspect, suspect))
+				found_guilty_entry(ent);
+		origin_decref(suspect);
+
+		if (DEBUG) /* sanity */
+			sanity_check_refcnt(sb);
+	}
+}
+
+static const char *format_time(unsigned long time, const char *tz_str,
+			       int show_raw_time)
+{
+	static char time_buf[128];
+	const char *time_str;
+	int time_len;
+	int tz;
+
+	if (show_raw_time) {
+		sprintf(time_buf, "%lu %s", time, tz_str);
+	}
+	else {
+		tz = atoi(tz_str);
+		time_str = show_date(time, tz, blame_date_mode);
+		time_len = strlen(time_str);
+		memcpy(time_buf, time_str, time_len);
+		memset(time_buf + time_len, ' ', blame_date_width - time_len);
+	}
+	return time_buf;
+}
+
+#define OUTPUT_ANNOTATE_COMPAT	001
+#define OUTPUT_LONG_OBJECT_NAME	002
+#define OUTPUT_RAW_TIMESTAMP	004
+#define OUTPUT_PORCELAIN	010
+#define OUTPUT_SHOW_NAME	020
+#define OUTPUT_SHOW_NUMBER	040
+#define OUTPUT_SHOW_SCORE      0100
+#define OUTPUT_NO_AUTHOR       0200
+
+static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent)
+{
+	int cnt;
+	const char *cp;
+	struct origin *suspect = ent->suspect;
+	char hex[41];
+
+	strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
+	printf("%s%c%d %d %d\n",
+	       hex,
+	       ent->guilty ? ' ' : '*', // purely for debugging
+	       ent->s_lno + 1,
+	       ent->lno + 1,
+	       ent->num_lines);
+	if (emit_one_suspect_detail(suspect) ||
+	    (suspect->commit->object.flags & MORE_THAN_ONE_PATH))
+		write_filename_info(suspect->path);
+
+	cp = nth_line(sb, ent->lno);
+	for (cnt = 0; cnt < ent->num_lines; cnt++) {
+		char ch;
+		if (cnt)
+			printf("%s %d %d\n", hex,
+			       ent->s_lno + 1 + cnt,
+			       ent->lno + 1 + cnt);
+		putchar('\t');
+		do {
+			ch = *cp++;
+			putchar(ch);
+		} while (ch != '\n' &&
+			 cp < sb->final_buf + sb->final_buf_size);
+	}
+
+	if (sb->final_buf_size && cp[-1] != '\n')
+		putchar('\n');
+}
+
+static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
+{
+	int cnt;
+	const char *cp;
+	struct origin *suspect = ent->suspect;
+	struct commit_info ci;
+	char hex[41];
+	int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
+
+	get_commit_info(suspect->commit, &ci, 1);
+	strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
+
+	cp = nth_line(sb, ent->lno);
+	for (cnt = 0; cnt < ent->num_lines; cnt++) {
+		char ch;
+		int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? 40 : 8;
+
+		if (suspect->commit->object.flags & UNINTERESTING) {
+			if (blank_boundary)
+				memset(hex, ' ', length);
+			else if (!(opt & OUTPUT_ANNOTATE_COMPAT)) {
+				length--;
+				putchar('^');
+			}
+		}
+
+		printf("%.*s", length, hex);
+		if (opt & OUTPUT_ANNOTATE_COMPAT)
+			printf("\t(%10s\t%10s\t%d)", ci.author,
+			       format_time(ci.author_time, ci.author_tz,
+					   show_raw_time),
+			       ent->lno + 1 + cnt);
+		else {
+			if (opt & OUTPUT_SHOW_SCORE)
+				printf(" %*d %02d",
+				       max_score_digits, ent->score,
+				       ent->suspect->refcnt);
+			if (opt & OUTPUT_SHOW_NAME)
+				printf(" %-*.*s", longest_file, longest_file,
+				       suspect->path);
+			if (opt & OUTPUT_SHOW_NUMBER)
+				printf(" %*d", max_orig_digits,
+				       ent->s_lno + 1 + cnt);
+
+			if (!(opt & OUTPUT_NO_AUTHOR)) {
+				int pad = longest_author - utf8_strwidth(ci.author);
+				printf(" (%s%*s %10s",
+				       ci.author, pad, "",
+				       format_time(ci.author_time,
+						   ci.author_tz,
+						   show_raw_time));
+			}
+			printf(" %*d) ",
+			       max_digits, ent->lno + 1 + cnt);
+		}
+		do {
+			ch = *cp++;
+			putchar(ch);
+		} while (ch != '\n' &&
+			 cp < sb->final_buf + sb->final_buf_size);
+	}
+
+	if (sb->final_buf_size && cp[-1] != '\n')
+		putchar('\n');
+}
+
+static void output(struct scoreboard *sb, int option)
+{
+	struct blame_entry *ent;
+
+	if (option & OUTPUT_PORCELAIN) {
+		for (ent = sb->ent; ent; ent = ent->next) {
+			struct blame_entry *oth;
+			struct origin *suspect = ent->suspect;
+			struct commit *commit = suspect->commit;
+			if (commit->object.flags & MORE_THAN_ONE_PATH)
+				continue;
+			for (oth = ent->next; oth; oth = oth->next) {
+				if ((oth->suspect->commit != commit) ||
+				    !strcmp(oth->suspect->path, suspect->path))
+					continue;
+				commit->object.flags |= MORE_THAN_ONE_PATH;
+				break;
+			}
+		}
+	}
+
+	for (ent = sb->ent; ent; ent = ent->next) {
+		if (option & OUTPUT_PORCELAIN)
+			emit_porcelain(sb, ent);
+		else {
+			emit_other(sb, ent, option);
+		}
+	}
+}
+
+/*
+ * To allow quick access to the contents of nth line in the
+ * final image, prepare an index in the scoreboard.
+ */
+static int prepare_lines(struct scoreboard *sb)
+{
+	const char *buf = sb->final_buf;
+	unsigned long len = sb->final_buf_size;
+	int num = 0, incomplete = 0, bol = 1;
+
+	if (len && buf[len-1] != '\n')
+		incomplete++; /* incomplete line at the end */
+	while (len--) {
+		if (bol) {
+			sb->lineno = xrealloc(sb->lineno,
+					      sizeof(int *) * (num + 1));
+			sb->lineno[num] = buf - sb->final_buf;
+			bol = 0;
+		}
+		if (*buf++ == '\n') {
+			num++;
+			bol = 1;
+		}
+	}
+	sb->lineno = xrealloc(sb->lineno,
+			      sizeof(int *) * (num + incomplete + 1));
+	sb->lineno[num + incomplete] = buf - sb->final_buf;
+	sb->num_lines = num + incomplete;
+	return sb->num_lines;
+}
+
+/*
+ * Add phony grafts for use with -S; this is primarily to
+ * support git's cvsserver that wants to give a linear history
+ * to its clients.
+ */
+static int read_ancestry(const char *graft_file)
+{
+	FILE *fp = fopen(graft_file, "r");
+	char buf[1024];
+	if (!fp)
+		return -1;
+	while (fgets(buf, sizeof(buf), fp)) {
+		/* The format is just "Commit Parent1 Parent2 ...\n" */
+		int len = strlen(buf);
+		struct commit_graft *graft = read_graft_line(buf, len);
+		if (graft)
+			register_commit_graft(graft, 0);
+	}
+	fclose(fp);
+	return 0;
+}
+
+/*
+ * How many columns do we need to show line numbers in decimal?
+ */
+static int lineno_width(int lines)
+{
+	int i, width;
+
+	for (width = 1, i = 10; i <= lines + 1; width++)
+		i *= 10;
+	return width;
+}
+
+/*
+ * How many columns do we need to show line numbers, authors,
+ * and filenames?
+ */
+static void find_alignment(struct scoreboard *sb, int *option)
+{
+	int longest_src_lines = 0;
+	int longest_dst_lines = 0;
+	unsigned largest_score = 0;
+	struct blame_entry *e;
+
+	for (e = sb->ent; e; e = e->next) {
+		struct origin *suspect = e->suspect;
+		struct commit_info ci;
+		int num;
+
+		if (strcmp(suspect->path, sb->path))
+			*option |= OUTPUT_SHOW_NAME;
+		num = strlen(suspect->path);
+		if (longest_file < num)
+			longest_file = num;
+		if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
+			suspect->commit->object.flags |= METAINFO_SHOWN;
+			get_commit_info(suspect->commit, &ci, 1);
+			num = utf8_strwidth(ci.author);
+			if (longest_author < num)
+				longest_author = num;
+		}
+		num = e->s_lno + e->num_lines;
+		if (longest_src_lines < num)
+			longest_src_lines = num;
+		num = e->lno + e->num_lines;
+		if (longest_dst_lines < num)
+			longest_dst_lines = num;
+		if (largest_score < ent_score(sb, e))
+			largest_score = ent_score(sb, e);
+	}
+	max_orig_digits = lineno_width(longest_src_lines);
+	max_digits = lineno_width(longest_dst_lines);
+	max_score_digits = lineno_width(largest_score);
+}
+
+/*
+ * For debugging -- origin is refcounted, and this asserts that
+ * we do not underflow.
+ */
+static void sanity_check_refcnt(struct scoreboard *sb)
+{
+	int baa = 0;
+	struct blame_entry *ent;
+
+	for (ent = sb->ent; ent; ent = ent->next) {
+		/* Nobody should have zero or negative refcnt */
+		if (ent->suspect->refcnt <= 0) {
+			fprintf(stderr, "%s in %s has negative refcnt %d\n",
+				ent->suspect->path,
+				sha1_to_hex(ent->suspect->commit->object.sha1),
+				ent->suspect->refcnt);
+			baa = 1;
+		}
+	}
+	if (baa) {
+		int opt = 0160;
+		find_alignment(sb, &opt);
+		output(sb, opt);
+		die("Baa %d!", baa);
+	}
+}
+
+/*
+ * Used for the command line parsing; check if the path exists
+ * in the working tree.
+ */
+static int has_string_in_work_tree(const char *path)
+{
+	struct stat st;
+	return !lstat(path, &st);
+}
+
+static unsigned parse_score(const char *arg)
+{
+	char *end;
+	unsigned long score = strtoul(arg, &end, 10);
+	if (*end)
+		return 0;
+	return score;
+}
+
+static const char *add_prefix(const char *prefix, const char *path)
+{
+	return prefix_path(prefix, prefix ? strlen(prefix) : 0, path);
+}
+
+/*
+ * Parsing of (comma separated) one item in the -L option
+ */
+static const char *parse_loc(const char *spec,
+			     struct scoreboard *sb, long lno,
+			     long begin, long *ret)
+{
+	char *term;
+	const char *line;
+	long num;
+	int reg_error;
+	regex_t regexp;
+	regmatch_t match[1];
+
+	/* Allow "-L <something>,+20" to mean starting at <something>
+	 * for 20 lines, or "-L <something>,-5" for 5 lines ending at
+	 * <something>.
+	 */
+	if (1 < begin && (spec[0] == '+' || spec[0] == '-')) {
+		num = strtol(spec + 1, &term, 10);
+		if (term != spec + 1) {
+			if (spec[0] == '-')
+				num = 0 - num;
+			if (0 < num)
+				*ret = begin + num - 2;
+			else if (!num)
+				*ret = begin;
+			else
+				*ret = begin + num;
+			return term;
+		}
+		return spec;
+	}
+	num = strtol(spec, &term, 10);
+	if (term != spec) {
+		*ret = num;
+		return term;
+	}
+	if (spec[0] != '/')
+		return spec;
+
+	/* it could be a regexp of form /.../ */
+	for (term = (char *) spec + 1; *term && *term != '/'; term++) {
+		if (*term == '\\')
+			term++;
+	}
+	if (*term != '/')
+		return spec;
+
+	/* try [spec+1 .. term-1] as regexp */
+	*term = 0;
+	begin--; /* input is in human terms */
+	line = nth_line(sb, begin);
+
+	if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
+	    !(reg_error = regexec(&regexp, line, 1, match, 0))) {
+		const char *cp = line + match[0].rm_so;
+		const char *nline;
+
+		while (begin++ < lno) {
+			nline = nth_line(sb, begin);
+			if (line <= cp && cp < nline)
+				break;
+			line = nline;
+		}
+		*ret = begin;
+		regfree(&regexp);
+		*term++ = '/';
+		return term;
+	}
+	else {
+		char errbuf[1024];
+		regerror(reg_error, &regexp, errbuf, 1024);
+		die("-L parameter '%s': %s", spec + 1, errbuf);
+	}
+}
+
+/*
+ * Parsing of -L option
+ */
+static void prepare_blame_range(struct scoreboard *sb,
+				const char *bottomtop,
+				long lno,
+				long *bottom, long *top)
+{
+	const char *term;
+
+	term = parse_loc(bottomtop, sb, lno, 1, bottom);
+	if (*term == ',') {
+		term = parse_loc(term + 1, sb, lno, *bottom + 1, top);
+		if (*term)
+			usage(blame_usage);
+	}
+	if (*term)
+		usage(blame_usage);
+}
+
+static int git_blame_config(const char *var, const char *value, void *cb)
+{
+	if (!strcmp(var, "blame.showroot")) {
+		show_root = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "blame.blankboundary")) {
+		blank_boundary = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "blame.date")) {
+		if (!value)
+			return config_error_nonbool(var);
+		blame_date_mode = parse_date_format(value);
+		return 0;
+	}
+	return git_default_config(var, value, cb);
+}
+
+/*
+ * Prepare a dummy commit that represents the work tree (or staged) item.
+ * Note that annotating work tree item never works in the reverse.
+ */
+static struct commit *fake_working_tree_commit(const char *path, const char *contents_from)
+{
+	struct commit *commit;
+	struct origin *origin;
+	unsigned char head_sha1[20];
+	struct strbuf buf = STRBUF_INIT;
+	const char *ident;
+	time_t now;
+	int size, len;
+	struct cache_entry *ce;
+	unsigned mode;
+
+	if (get_sha1("HEAD", head_sha1))
+		die("No such ref: HEAD");
+
+	time(&now);
+	commit = xcalloc(1, sizeof(*commit));
+	commit->parents = xcalloc(1, sizeof(*commit->parents));
+	commit->parents->item = lookup_commit_reference(head_sha1);
+	commit->object.parsed = 1;
+	commit->date = now;
+	commit->object.type = OBJ_COMMIT;
+
+	origin = make_origin(commit, path);
+
+	if (!contents_from || strcmp("-", contents_from)) {
+		struct stat st;
+		const char *read_from;
+
+		if (contents_from) {
+			if (stat(contents_from, &st) < 0)
+				die_errno("Cannot stat '%s'", contents_from);
+			read_from = contents_from;
+		}
+		else {
+			if (lstat(path, &st) < 0)
+				die_errno("Cannot lstat '%s'", path);
+			read_from = path;
+		}
+		mode = canon_mode(st.st_mode);
+		switch (st.st_mode & S_IFMT) {
+		case S_IFREG:
+			if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
+				die_errno("cannot open or read '%s'", read_from);
+			break;
+		case S_IFLNK:
+			if (strbuf_readlink(&buf, read_from, st.st_size) < 0)
+				die_errno("cannot readlink '%s'", read_from);
+			break;
+		default:
+			die("unsupported file type %s", read_from);
+		}
+	}
+	else {
+		/* Reading from stdin */
+		contents_from = "standard input";
+		mode = 0;
+		if (strbuf_read(&buf, 0, 0) < 0)
+			die_errno("failed to read from stdin");
+	}
+	convert_to_git(path, buf.buf, buf.len, &buf, 0);
+	origin->file.ptr = buf.buf;
+	origin->file.size = buf.len;
+	pretend_sha1_file(buf.buf, buf.len, OBJ_BLOB, origin->blob_sha1);
+	commit->util = origin;
+
+	/*
+	 * Read the current index, replace the path entry with
+	 * origin->blob_sha1 without mucking with its mode or type
+	 * bits; we are not going to write this index out -- we just
+	 * want to run "diff-index --cached".
+	 */
+	discard_cache();
+	read_cache();
+
+	len = strlen(path);
+	if (!mode) {
+		int pos = cache_name_pos(path, len);
+		if (0 <= pos)
+			mode = active_cache[pos]->ce_mode;
+		else
+			/* Let's not bother reading from HEAD tree */
+			mode = S_IFREG | 0644;
+	}
+	size = cache_entry_size(len);
+	ce = xcalloc(1, size);
+	hashcpy(ce->sha1, origin->blob_sha1);
+	memcpy(ce->name, path, len);
+	ce->ce_flags = create_ce_flags(len, 0);
+	ce->ce_mode = create_ce_mode(mode);
+	add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
+
+	/*
+	 * We are not going to write this out, so this does not matter
+	 * right now, but someday we might optimize diff-index --cached
+	 * with cache-tree information.
+	 */
+	cache_tree_invalidate_path(active_cache_tree, path);
+
+	commit->buffer = xmalloc(400);
+	ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
+	snprintf(commit->buffer, 400,
+		"tree 0000000000000000000000000000000000000000\n"
+		"parent %s\n"
+		"author %s\n"
+		"committer %s\n\n"
+		"Version of %s from %s\n",
+		sha1_to_hex(head_sha1),
+		ident, ident, path, contents_from ? contents_from : path);
+	return commit;
+}
+
+static const char *prepare_final(struct scoreboard *sb)
+{
+	int i;
+	const char *final_commit_name = NULL;
+	struct rev_info *revs = sb->revs;
+
+	/*
+	 * There must be one and only one positive commit in the
+	 * revs->pending array.
+	 */
+	for (i = 0; i < revs->pending.nr; i++) {
+		struct object *obj = revs->pending.objects[i].item;
+		if (obj->flags & UNINTERESTING)
+			continue;
+		while (obj->type == OBJ_TAG)
+			obj = deref_tag(obj, NULL, 0);
+		if (obj->type != OBJ_COMMIT)
+			die("Non commit %s?", revs->pending.objects[i].name);
+		if (sb->final)
+			die("More than one commit to dig from %s and %s?",
+			    revs->pending.objects[i].name,
+			    final_commit_name);
+		sb->final = (struct commit *) obj;
+		final_commit_name = revs->pending.objects[i].name;
+	}
+	return final_commit_name;
+}
+
+static const char *prepare_initial(struct scoreboard *sb)
+{
+	int i;
+	const char *final_commit_name = NULL;
+	struct rev_info *revs = sb->revs;
+
+	/*
+	 * There must be one and only one negative commit, and it must be
+	 * the boundary.
+	 */
+	for (i = 0; i < revs->pending.nr; i++) {
+		struct object *obj = revs->pending.objects[i].item;
+		if (!(obj->flags & UNINTERESTING))
+			continue;
+		while (obj->type == OBJ_TAG)
+			obj = deref_tag(obj, NULL, 0);
+		if (obj->type != OBJ_COMMIT)
+			die("Non commit %s?", revs->pending.objects[i].name);
+		if (sb->final)
+			die("More than one commit to dig down to %s and %s?",
+			    revs->pending.objects[i].name,
+			    final_commit_name);
+		sb->final = (struct commit *) obj;
+		final_commit_name = revs->pending.objects[i].name;
+	}
+	if (!final_commit_name)
+		die("No commit to dig down to?");
+	return final_commit_name;
+}
+
+static int blame_copy_callback(const struct option *option, const char *arg, int unset)
+{
+	int *opt = option->value;
+
+	/*
+	 * -C enables copy from removed files;
+	 * -C -C enables copy from existing files, but only
+	 *       when blaming a new file;
+	 * -C -C -C enables copy from existing files for
+	 *          everybody
+	 */
+	if (*opt & PICKAXE_BLAME_COPY_HARDER)
+		*opt |= PICKAXE_BLAME_COPY_HARDEST;
+	if (*opt & PICKAXE_BLAME_COPY)
+		*opt |= PICKAXE_BLAME_COPY_HARDER;
+	*opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;
+
+	if (arg)
+		blame_copy_score = parse_score(arg);
+	return 0;
+}
+
+static int blame_move_callback(const struct option *option, const char *arg, int unset)
+{
+	int *opt = option->value;
+
+	*opt |= PICKAXE_BLAME_MOVE;
+
+	if (arg)
+		blame_move_score = parse_score(arg);
+	return 0;
+}
+
+static int blame_bottomtop_callback(const struct option *option, const char *arg, int unset)
+{
+	const char **bottomtop = option->value;
+	if (!arg)
+		return -1;
+	if (*bottomtop)
+		die("More than one '-L n,m' option given");
+	*bottomtop = arg;
+	return 0;
+}
+
+int cmd_blame(int argc, const char **argv, const char *prefix)
+{
+	struct rev_info revs;
+	const char *path;
+	struct scoreboard sb;
+	struct origin *o;
+	struct blame_entry *ent;
+	long dashdash_pos, bottom, top, lno;
+	const char *final_commit_name = NULL;
+	enum object_type type;
+
+	static const char *bottomtop = NULL;
+	static int output_option = 0, opt = 0;
+	static int show_stats = 0;
+	static const char *revs_file = NULL;
+	static const char *contents_from = NULL;
+	static const struct option options[] = {
+		OPT_BOOLEAN(0, "incremental", &incremental, "Show blame entries as we find them, incrementally"),
+		OPT_BOOLEAN('b', NULL, &blank_boundary, "Show blank SHA-1 for boundary commits (Default: off)"),
+		OPT_BOOLEAN(0, "root", &show_root, "Do not treat root commits as boundaries (Default: off)"),
+		OPT_BOOLEAN(0, "show-stats", &show_stats, "Show work cost statistics"),
+		OPT_BIT(0, "score-debug", &output_option, "Show output score for blame entries", OUTPUT_SHOW_SCORE),
+		OPT_BIT('f', "show-name", &output_option, "Show original filename (Default: auto)", OUTPUT_SHOW_NAME),
+		OPT_BIT('n', "show-number", &output_option, "Show original linenumber (Default: off)", OUTPUT_SHOW_NUMBER),
+		OPT_BIT('p', "porcelain", &output_option, "Show in a format designed for machine consumption", OUTPUT_PORCELAIN),
+		OPT_BIT('c', NULL, &output_option, "Use the same output mode as git-annotate (Default: off)", OUTPUT_ANNOTATE_COMPAT),
+		OPT_BIT('t', NULL, &output_option, "Show raw timestamp (Default: off)", OUTPUT_RAW_TIMESTAMP),
+		OPT_BIT('l', NULL, &output_option, "Show long commit SHA1 (Default: off)", OUTPUT_LONG_OBJECT_NAME),
+		OPT_BIT('s', NULL, &output_option, "Suppress author name and timestamp (Default: off)", OUTPUT_NO_AUTHOR),
+		OPT_BIT('w', NULL, &xdl_opts, "Ignore whitespace differences", XDF_IGNORE_WHITESPACE),
+		OPT_STRING('S', NULL, &revs_file, "file", "Use revisions from <file> instead of calling git-rev-list"),
+		OPT_STRING(0, "contents", &contents_from, "file", "Use <file>'s contents as the final image"),
+		{ OPTION_CALLBACK, 'C', NULL, &opt, "score", "Find line copies within and across files", PARSE_OPT_OPTARG, blame_copy_callback },
+		{ OPTION_CALLBACK, 'M', NULL, &opt, "score", "Find line movements within and across files", PARSE_OPT_OPTARG, blame_move_callback },
+		OPT_CALLBACK('L', NULL, &bottomtop, "n,m", "Process only line range n,m, counting from 1", blame_bottomtop_callback),
+		OPT_END()
+	};
+
+	struct parse_opt_ctx_t ctx;
+	int cmd_is_annotate = !strcmp(argv[0], "annotate");
+
+	git_config(git_blame_config, NULL);
+	init_revisions(&revs, NULL);
+	revs.date_mode = blame_date_mode;
+
+	save_commit_buffer = 0;
+	dashdash_pos = 0;
+
+	parse_options_start(&ctx, argc, argv, prefix, PARSE_OPT_KEEP_DASHDASH |
+			    PARSE_OPT_KEEP_ARGV0);
+	for (;;) {
+		switch (parse_options_step(&ctx, options, blame_opt_usage)) {
+		case PARSE_OPT_HELP:
+			exit(129);
+		case PARSE_OPT_DONE:
+			if (ctx.argv[0])
+				dashdash_pos = ctx.cpidx;
+			goto parse_done;
+		}
+
+		if (!strcmp(ctx.argv[0], "--reverse")) {
+			ctx.argv[0] = "--children";
+			reverse = 1;
+		}
+		parse_revision_opt(&revs, &ctx, options, blame_opt_usage);
+	}
+parse_done:
+	argc = parse_options_end(&ctx);
+
+	if (revs_file && read_ancestry(revs_file))
+		die_errno("reading graft file '%s' failed", revs_file);
+
+	if (cmd_is_annotate) {
+		output_option |= OUTPUT_ANNOTATE_COMPAT;
+		blame_date_mode = DATE_ISO8601;
+	} else {
+		blame_date_mode = revs.date_mode;
+	}
+
+	/* The maximum width used to show the dates */
+	switch (blame_date_mode) {
+	case DATE_RFC2822:
+		blame_date_width = sizeof("Thu, 19 Oct 2006 16:00:04 -0700");
+		break;
+	case DATE_ISO8601:
+		blame_date_width = sizeof("2006-10-19 16:00:04 -0700");
+		break;
+	case DATE_RAW:
+		blame_date_width = sizeof("1161298804 -0700");
+		break;
+	case DATE_SHORT:
+		blame_date_width = sizeof("2006-10-19");
+		break;
+	case DATE_RELATIVE:
+		/* "normal" is used as the fallback for "relative" */
+	case DATE_LOCAL:
+	case DATE_NORMAL:
+		blame_date_width = sizeof("Thu Oct 19 16:00:04 2006 -0700");
+		break;
+	}
+	blame_date_width -= 1; /* strip the null */
+
+	if (DIFF_OPT_TST(&revs.diffopt, FIND_COPIES_HARDER))
+		opt |= (PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE |
+			PICKAXE_BLAME_COPY_HARDER);
+
+	if (!blame_move_score)
+		blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
+	if (!blame_copy_score)
+		blame_copy_score = BLAME_DEFAULT_COPY_SCORE;
+
+	/*
+	 * We have collected options unknown to us in argv[1..unk]
+	 * which are to be passed to revision machinery if we are
+	 * going to do the "bottom" processing.
+	 *
+	 * The remaining are:
+	 *
+	 * (1) if dashdash_pos != 0, its either
+	 *     "blame [revisions] -- <path>" or
+	 *     "blame -- <path> <rev>"
+	 *
+	 * (2) otherwise, its one of the two:
+	 *     "blame [revisions] <path>"
+	 *     "blame <path> <rev>"
+	 *
+	 * Note that we must strip out <path> from the arguments: we do not
+	 * want the path pruning but we may want "bottom" processing.
+	 */
+	if (dashdash_pos) {
+		switch (argc - dashdash_pos - 1) {
+		case 2: /* (1b) */
+			if (argc != 4)
+				usage_with_options(blame_opt_usage, options);
+			/* reorder for the new way: <rev> -- <path> */
+			argv[1] = argv[3];
+			argv[3] = argv[2];
+			argv[2] = "--";
+			/* FALLTHROUGH */
+		case 1: /* (1a) */
+			path = add_prefix(prefix, argv[--argc]);
+			argv[argc] = NULL;
+			break;
+		default:
+			usage_with_options(blame_opt_usage, options);
+		}
+	} else {
+		if (argc < 2)
+			usage_with_options(blame_opt_usage, options);
+		path = add_prefix(prefix, argv[argc - 1]);
+		if (argc == 3 && !has_string_in_work_tree(path)) { /* (2b) */
+			path = add_prefix(prefix, argv[1]);
+			argv[1] = argv[2];
+		}
+		argv[argc - 1] = "--";
+
+		setup_work_tree();
+		if (!has_string_in_work_tree(path))
+			die_errno("cannot stat path '%s'", path);
+	}
+
+	revs.disable_stdin = 1;
+	setup_revisions(argc, argv, &revs, NULL);
+	memset(&sb, 0, sizeof(sb));
+
+	sb.revs = &revs;
+	if (!reverse)
+		final_commit_name = prepare_final(&sb);
+	else if (contents_from)
+		die("--contents and --children do not blend well.");
+	else
+		final_commit_name = prepare_initial(&sb);
+
+	if (!sb.final) {
+		/*
+		 * "--not A B -- path" without anything positive;
+		 * do not default to HEAD, but use the working tree
+		 * or "--contents".
+		 */
+		setup_work_tree();
+		sb.final = fake_working_tree_commit(path, contents_from);
+		add_pending_object(&revs, &(sb.final->object), ":");
+	}
+	else if (contents_from)
+		die("Cannot use --contents with final commit object name");
+
+	/*
+	 * If we have bottom, this will mark the ancestors of the
+	 * bottom commits we would reach while traversing as
+	 * uninteresting.
+	 */
+	if (prepare_revision_walk(&revs))
+		die("revision walk setup failed");
+
+	if (is_null_sha1(sb.final->object.sha1)) {
+		char *buf;
+		o = sb.final->util;
+		buf = xmalloc(o->file.size + 1);
+		memcpy(buf, o->file.ptr, o->file.size + 1);
+		sb.final_buf = buf;
+		sb.final_buf_size = o->file.size;
+	}
+	else {
+		o = get_origin(&sb, sb.final, path);
+		if (fill_blob_sha1(o))
+			die("no such path %s in %s", path, final_commit_name);
+
+		sb.final_buf = read_sha1_file(o->blob_sha1, &type,
+					      &sb.final_buf_size);
+		if (!sb.final_buf)
+			die("Cannot read blob %s for path %s",
+			    sha1_to_hex(o->blob_sha1),
+			    path);
+	}
+	num_read_blob++;
+	lno = prepare_lines(&sb);
+
+	bottom = top = 0;
+	if (bottomtop)
+		prepare_blame_range(&sb, bottomtop, lno, &bottom, &top);
+	if (bottom && top && top < bottom) {
+		long tmp;
+		tmp = top; top = bottom; bottom = tmp;
+	}
+	if (bottom < 1)
+		bottom = 1;
+	if (top < 1)
+		top = lno;
+	bottom--;
+	if (lno < top || lno < bottom)
+		die("file %s has only %lu lines", path, lno);
+
+	ent = xcalloc(1, sizeof(*ent));
+	ent->lno = bottom;
+	ent->num_lines = top - bottom;
+	ent->suspect = o;
+	ent->s_lno = bottom;
+
+	sb.ent = ent;
+	sb.path = path;
+
+	read_mailmap(&mailmap, NULL);
+
+	if (!incremental)
+		setup_pager();
+
+	assign_blame(&sb, opt);
+
+	if (incremental)
+		return 0;
+
+	coalesce(&sb);
+
+	if (!(output_option & OUTPUT_PORCELAIN))
+		find_alignment(&sb, &output_option);
+
+	output(&sb, output_option);
+	free((void *)sb.final_buf);
+	for (ent = sb.ent; ent; ) {
+		struct blame_entry *e = ent->next;
+		free(ent);
+		ent = e;
+	}
+
+	if (show_stats) {
+		printf("num read blob: %d\n", num_read_blob);
+		printf("num get patch: %d\n", num_get_patch);
+		printf("num commits: %d\n", num_commits);
+	}
+	return 0;
+}