1 files changed, 278 insertions, 147 deletions

diff --git a/builtin/blame.c b/builtin/blame.c
index 303e217ae9..4ddfadb71f 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -6,6 +6,7 @@
  */
 
 #include "cache.h"
+#include "refs.h"
 #include "builtin.h"
 #include "blob.h"
 #include "commit.h"
@@ -26,13 +27,15 @@
 #include "userdiff.h"
 #include "line-range.h"
 #include "line-log.h"
+#include "dir.h"
+#include "progress.h"
 
-static char blame_usage[] = N_("git blame [options] [rev-opts] [rev] [--] file");
+static char blame_usage[] = N_("git blame [<options>] [<rev-opts>] [<rev>] [--] <file>");
 
 static const char *blame_opt_usage[] = {
 	blame_usage,
 	"",
-	N_("[rev-opts] are documented in git-rev-list(1)"),
+	N_("<rev-opts> are documented in git-rev-list(1)"),
 	NULL
 };
 
@@ -48,11 +51,12 @@ static int incremental;
 static int xdl_opts;
 static int abbrev = -1;
 static int no_whole_file_rename;
+static int show_progress;
 
-static enum date_mode blame_date_mode = DATE_ISO8601;
+static struct date_mode blame_date_mode = { DATE_ISO8601 };
 static size_t blame_date_width;
 
-static struct string_list mailmap;
+static struct string_list mailmap = STRING_LIST_INIT_NODUP;
 
 #ifndef DEBUG
 #define DEBUG 0
@@ -116,7 +120,7 @@ struct origin {
 	 */
 	struct blame_entry *suspects;
 	mmfile_t file;
-	unsigned char blob_sha1[20];
+	struct object_id blob_oid;
 	unsigned mode;
 	/* guilty gets set when shipping any suspects to the final
 	 * blame list instead of other commits
@@ -125,7 +129,12 @@ struct origin {
 	char path[FLEX_ARRAY];
 };
 
-static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b, long ctxlen,
+struct progress_info {
+	struct progress *progress;
+	int blamed_lines;
+};
+
+static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b,
 		      xdl_emit_hunk_consume_func_t hunk_func, void *cb_data)
 {
 	xpparam_t xpp = {0};
@@ -133,7 +142,6 @@ static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b, long ctxlen,
 	xdemitcb_t ecb = {NULL};
 
 	xpp.flags = xdl_opts;
-	xecfg.ctxlen = ctxlen;
 	xecfg.hunk_func = hunk_func;
 	ecb.priv = cb_data;
 	return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb);
@@ -146,8 +154,8 @@ static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b, long ctxlen,
  */
 int textconv_object(const char *path,
 		    unsigned mode,
-		    const unsigned char *sha1,
-		    int sha1_valid,
+		    const struct object_id *oid,
+		    int oid_valid,
 		    char **buf,
 		    unsigned long *buf_size)
 {
@@ -155,7 +163,7 @@ int textconv_object(const char *path,
 	struct userdiff_driver *textconv;
 
 	df = alloc_filespec(path);
-	fill_filespec(df, sha1, sha1_valid, mode);
+	fill_filespec(df, oid->hash, oid_valid, mode);
 	textconv = get_textconv(df);
 	if (!textconv) {
 		free_filespec(df);
@@ -180,15 +188,16 @@ static void fill_origin_blob(struct diff_options *opt,
 
 		num_read_blob++;
 		if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
-		    textconv_object(o->path, o->mode, o->blob_sha1, 1, &file->ptr, &file_size))
+		    textconv_object(o->path, o->mode, &o->blob_oid, 1, &file->ptr, &file_size))
 			;
 		else
-			file->ptr = read_sha1_file(o->blob_sha1, &type, &file_size);
+			file->ptr = read_sha1_file(o->blob_oid.hash, &type,
+						   &file_size);
 		file->size = file_size;
 
 		if (!file->ptr)
 			die("Cannot read blob %s for path %s",
-			    sha1_to_hex(o->blob_sha1),
+			    oid_to_hex(&o->blob_oid),
 			    o->path);
 		o->file = *file;
 	}
@@ -457,12 +466,11 @@ static void queue_blames(struct scoreboard *sb, struct origin *porigin,
 static struct origin *make_origin(struct commit *commit, const char *path)
 {
 	struct origin *o;
-	o = xcalloc(1, sizeof(*o) + strlen(path) + 1);
+	FLEX_ALLOC_STR(o, path, path);
 	o->commit = commit;
 	o->refcnt = 1;
 	o->next = commit->util;
 	commit->util = o;
-	strcpy(o->path, path);
 	return o;
 }
 
@@ -501,17 +509,17 @@ static struct origin *get_origin(struct scoreboard *sb,
  */
 static int fill_blob_sha1_and_mode(struct origin *origin)
 {
-	if (!is_null_sha1(origin->blob_sha1))
+	if (!is_null_oid(&origin->blob_oid))
 		return 0;
-	if (get_tree_entry(origin->commit->object.sha1,
+	if (get_tree_entry(origin->commit->object.oid.hash,
 			   origin->path,
-			   origin->blob_sha1, &origin->mode))
+			   origin->blob_oid.hash, &origin->mode))
 		goto error_out;
-	if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB)
+	if (sha1_object_info(origin->blob_oid.hash, NULL) != OBJ_BLOB)
 		goto error_out;
 	return 0;
  error_out:
-	hashclr(origin->blob_sha1);
+	oidclr(&origin->blob_oid);
 	origin->mode = S_IFINVALID;
 	return -1;
 }
@@ -554,18 +562,18 @@ static struct origin *find_origin(struct scoreboard *sb,
 		       PATHSPEC_LITERAL_PATH, "", paths);
 	diff_setup_done(&diff_opts);
 
-	if (is_null_sha1(origin->commit->object.sha1))
-		do_diff_cache(parent->tree->object.sha1, &diff_opts);
+	if (is_null_oid(&origin->commit->object.oid))
+		do_diff_cache(parent->tree->object.oid.hash, &diff_opts);
 	else
-		diff_tree_sha1(parent->tree->object.sha1,
-			       origin->commit->tree->object.sha1,
+		diff_tree_sha1(parent->tree->object.oid.hash,
+			       origin->commit->tree->object.oid.hash,
 			       "", &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);
+		oidcpy(&porigin->blob_oid, &origin->blob_oid);
 		porigin->mode = origin->mode;
 	} else {
 		/*
@@ -591,7 +599,7 @@ static struct origin *find_origin(struct scoreboard *sb,
 			    p->status);
 		case 'M':
 			porigin = get_origin(sb, parent, origin->path);
-			hashcpy(porigin->blob_sha1, p->one->sha1);
+			oidcpy(&porigin->blob_oid, &p->one->oid);
 			porigin->mode = p->one->mode;
 			break;
 		case 'A':
@@ -601,7 +609,7 @@ static struct origin *find_origin(struct scoreboard *sb,
 		}
 	}
 	diff_flush(&diff_opts);
-	free_pathspec(&diff_opts.pathspec);
+	clear_pathspec(&diff_opts.pathspec);
 	return porigin;
 }
 
@@ -624,11 +632,11 @@ static struct origin *find_rename(struct scoreboard *sb,
 	diff_opts.single_follow = origin->path;
 	diff_setup_done(&diff_opts);
 
-	if (is_null_sha1(origin->commit->object.sha1))
-		do_diff_cache(parent->tree->object.sha1, &diff_opts);
+	if (is_null_oid(&origin->commit->object.oid))
+		do_diff_cache(parent->tree->object.oid.hash, &diff_opts);
 	else
-		diff_tree_sha1(parent->tree->object.sha1,
-			       origin->commit->tree->object.sha1,
+		diff_tree_sha1(parent->tree->object.oid.hash,
+			       origin->commit->tree->object.oid.hash,
 			       "", &diff_opts);
 	diffcore_std(&diff_opts);
 
@@ -637,13 +645,13 @@ static struct origin *find_rename(struct scoreboard *sb,
 		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);
+			oidcpy(&porigin->blob_oid, &p->one->oid);
 			porigin->mode = p->one->mode;
 			break;
 		}
 	}
 	diff_flush(&diff_opts);
-	free_pathspec(&diff_opts.pathspec);
+	clear_pathspec(&diff_opts.pathspec);
 	return porigin;
 }
 
@@ -972,7 +980,10 @@ static void pass_blame_to_parent(struct scoreboard *sb,
 	fill_origin_blob(&sb->revs->diffopt, target, &file_o);
 	num_get_patch++;
 
-	diff_hunks(&file_p, &file_o, 0, blame_chunk_cb, &d);
+	if (diff_hunks(&file_p, &file_o, blame_chunk_cb, &d))
+		die("unable to generate diff (%s -> %s)",
+		    oid_to_hex(&parent->commit->object.oid),
+		    oid_to_hex(&target->commit->object.oid));
 	/* The rest are the same as the parent */
 	blame_chunk(&d.dstq, &d.srcq, INT_MAX, d.offset, INT_MAX, parent);
 	*d.dstq = NULL;
@@ -1118,7 +1129,9 @@ static void find_copy_in_blob(struct scoreboard *sb,
 	 * file_p partially may match that image.
 	 */
 	memset(split, 0, sizeof(struct blame_entry [3]));
-	diff_hunks(file_p, &file_o, 1, handle_split_cb, &d);
+	if (diff_hunks(file_p, &file_o, handle_split_cb, &d))
+		die("unable to generate diff (%s)",
+		    oid_to_hex(&parent->commit->object.oid));
 	/* remainder, if any, all match the preimage */
 	handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
 }
@@ -1267,11 +1280,11 @@ static void find_copy_in_parent(struct scoreboard *sb,
 		&& (!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);
+	if (is_null_oid(&target->commit->object.oid))
+		do_diff_cache(parent->tree->object.oid.hash, &diff_opts);
 	else
-		diff_tree_sha1(parent->tree->object.sha1,
-			       target->commit->tree->object.sha1,
+		diff_tree_sha1(parent->tree->object.oid.hash,
+			       target->commit->tree->object.oid.hash,
 			       "", &diff_opts);
 
 	if (!DIFF_OPT_TST(&diff_opts, FIND_COPIES_HARDER))
@@ -1296,7 +1309,7 @@ static void find_copy_in_parent(struct scoreboard *sb,
 				continue;
 
 			norigin = get_origin(sb, parent, p->one->path);
-			hashcpy(norigin->blob_sha1, p->one->sha1);
+			oidcpy(&norigin->blob_oid, &p->one->oid);
 			norigin->mode = p->one->mode;
 			fill_origin_blob(&sb->revs->diffopt, norigin, &file_p);
 			if (!file_p.ptr)
@@ -1330,7 +1343,7 @@ static void find_copy_in_parent(struct scoreboard *sb,
 	} while (unblamed);
 	target->suspects = reverse_blame(leftover, NULL);
 	diff_flush(&diff_opts);
-	free_pathspec(&diff_opts.pathspec);
+	clear_pathspec(&diff_opts.pathspec);
 }
 
 /*
@@ -1364,8 +1377,15 @@ static void pass_whole_blame(struct scoreboard *sb,
  */
 static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit)
 {
-	if (!reverse)
+	if (!reverse) {
+		if (revs->first_parent_only &&
+		    commit->parents &&
+		    commit->parents->next) {
+			free_commit_list(commit->parents->next);
+			commit->parents->next = NULL;
+		}
 		return commit->parents;
+	}
 	return lookup_decoration(&revs->children, &commit->object);
 }
 
@@ -1439,15 +1459,14 @@ static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
 			porigin = find(sb, p, origin);
 			if (!porigin)
 				continue;
-			if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) {
+			if (!oidcmp(&porigin->blob_oid, &origin->blob_oid)) {
 				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)) {
+				    !oidcmp(&sg_origin[j]->blob_oid, &porigin->blob_oid)) {
 					same = 1;
 					break;
 				}
@@ -1675,7 +1694,7 @@ static void get_commit_info(struct commit *commit,
 	if (len)
 		strbuf_add(&ret->summary, subject, len);
 	else
-		strbuf_addf(&ret->summary, "(%s)", sha1_to_hex(commit->object.sha1));
+		strbuf_addf(&ret->summary, "(%s)", oid_to_hex(&commit->object.oid));
 
 	unuse_commit_buffer(commit, message);
 }
@@ -1718,7 +1737,7 @@ static int emit_one_suspect_detail(struct origin *suspect, int repeat)
 		printf("boundary\n");
 	if (suspect->previous) {
 		struct origin *prev = suspect->previous;
-		printf("previous %s ", sha1_to_hex(prev->commit->object.sha1));
+		printf("previous %s ", oid_to_hex(&prev->commit->object.oid));
 		write_name_quoted(prev->path, stdout, '\n');
 	}
 
@@ -1731,18 +1750,21 @@ static int emit_one_suspect_detail(struct origin *suspect, int repeat)
  * The blame_entry is found to be guilty for the range.
  * Show it in incremental output.
  */
-static void found_guilty_entry(struct blame_entry *ent)
+static void found_guilty_entry(struct blame_entry *ent,
+			   struct progress_info *pi)
 {
 	if (incremental) {
 		struct origin *suspect = ent->suspect;
 
 		printf("%s %d %d %d\n",
-		       sha1_to_hex(suspect->commit->object.sha1),
+		       oid_to_hex(&suspect->commit->object.oid),
 		       ent->s_lno + 1, ent->lno + 1, ent->num_lines);
 		emit_one_suspect_detail(suspect, 0);
 		write_filename_info(suspect->path);
 		maybe_flush_or_die(stdout, "stdout");
 	}
+	pi->blamed_lines += ent->num_lines;
+	display_progress(pi->progress, pi->blamed_lines);
 }
 
 /*
@@ -1753,6 +1775,11 @@ static void assign_blame(struct scoreboard *sb, int opt)
 {
 	struct rev_info *revs = sb->revs;
 	struct commit *commit = prio_queue_get(&sb->commits);
+	struct progress_info pi = { NULL, 0 };
+
+	if (show_progress)
+		pi.progress = start_progress_delay(_("Blaming lines"),
+						   sb->num_lines, 50, 1);
 
 	while (commit) {
 		struct blame_entry *ent;
@@ -1794,7 +1821,7 @@ static void assign_blame(struct scoreboard *sb, int opt)
 			suspect->guilty = 1;
 			for (;;) {
 				struct blame_entry *next = ent->next;
-				found_guilty_entry(ent);
+				found_guilty_entry(ent, &pi);
 				if (next) {
 					ent = next;
 					continue;
@@ -1810,6 +1837,8 @@ static void assign_blame(struct scoreboard *sb, int opt)
 		if (DEBUG) /* sanity */
 			sanity_check_refcnt(sb);
 	}
+
+	stop_progress(&pi.progress);
 }
 
 static const char *format_time(unsigned long time, const char *tz_str,
@@ -1826,7 +1855,7 @@ static const char *format_time(unsigned long time, const char *tz_str,
 		size_t time_width;
 		int tz;
 		tz = atoi(tz_str);
-		time_str = show_date(time, tz, blame_date_mode);
+		time_str = show_date(time, tz, &blame_date_mode);
 		strbuf_addstr(&time_buf, time_str);
 		/*
 		 * Add space paddings to time_buf to display a fixed width
@@ -1865,9 +1894,9 @@ static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent,
 	int cnt;
 	const char *cp;
 	struct origin *suspect = ent->suspect;
-	char hex[41];
+	char hex[GIT_SHA1_HEXSZ + 1];
 
-	strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
+	sha1_to_hex_r(hex, suspect->commit->object.oid.hash);
 	printf("%s %d %d %d\n",
 	       hex,
 	       ent->s_lno + 1,
@@ -1903,16 +1932,16 @@ static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
 	const char *cp;
 	struct origin *suspect = ent->suspect;
 	struct commit_info ci;
-	char hex[41];
+	char hex[GIT_SHA1_HEXSZ + 1];
 	int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
 
 	get_commit_info(suspect->commit, &ci, 1);
-	strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
+	sha1_to_hex_r(hex, suspect->commit->object.oid.hash);
 
 	cp = nth_line(sb, ent->lno);
 	for (cnt = 0; cnt < ent->num_lines; cnt++) {
 		char ch;
-		int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? 40 : abbrev;
+		int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? GIT_SHA1_HEXSZ : abbrev;
 
 		if (suspect->commit->object.flags & UNINTERESTING) {
 			if (blank_boundary)
@@ -2027,7 +2056,8 @@ static int prepare_lines(struct scoreboard *sb)
 	for (p = buf; p < end; p = get_next_line(p, end))
 		num++;
 
-	sb->lineno = lineno = xmalloc(sizeof(*sb->lineno) * (num + 1));
+	ALLOC_ARRAY(sb->lineno, num + 1);
+	lineno = sb->lineno;
 
 	for (p = buf; p < end; p = get_next_line(p, end))
 		*lineno++ = p - buf;
@@ -2062,7 +2092,7 @@ static int read_ancestry(const char *graft_file)
 
 static int update_auto_abbrev(int auto_abbrev, struct origin *suspect)
 {
-	const char *uniq = find_unique_abbrev(suspect->commit->object.sha1,
+	const char *uniq = find_unique_abbrev(suspect->commit->object.oid.hash,
 					      auto_abbrev);
 	int len = strlen(uniq);
 	if (auto_abbrev < len)
@@ -2081,11 +2111,10 @@ static void find_alignment(struct scoreboard *sb, int *option)
 	unsigned largest_score = 0;
 	struct blame_entry *e;
 	int compute_auto_abbrev = (abbrev < 0);
-	int auto_abbrev = default_abbrev;
+	int auto_abbrev = DEFAULT_ABBREV;
 
 	for (e = sb->ent; e; e = e->next) {
 		struct origin *suspect = e->suspect;
-		struct commit_info ci;
 		int num;
 
 		if (compute_auto_abbrev)
@@ -2096,6 +2125,7 @@ static void find_alignment(struct scoreboard *sb, int *option)
 		if (longest_file < num)
 			longest_file = num;
 		if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
+			struct commit_info ci;
 			suspect->commit->object.flags |= METAINFO_SHOWN;
 			get_commit_info(suspect->commit, &ci, 1);
 			if (*option & OUTPUT_SHOW_EMAIL)
@@ -2104,6 +2134,7 @@ static void find_alignment(struct scoreboard *sb, int *option)
 				num = utf8_strwidth(ci.author.buf);
 			if (longest_author < num)
 				longest_author = num;
+			commit_info_destroy(&ci);
 		}
 		num = e->s_lno + e->num_lines;
 		if (longest_src_lines < num)
@@ -2113,8 +2144,6 @@ static void find_alignment(struct scoreboard *sb, int *option)
 			longest_dst_lines = num;
 		if (largest_score < ent_score(sb, e))
 			largest_score = ent_score(sb, e);
-
-		commit_info_destroy(&ci);
 	}
 	max_orig_digits = decimal_width(longest_src_lines);
 	max_digits = decimal_width(longest_dst_lines);
@@ -2139,7 +2168,7 @@ static void sanity_check_refcnt(struct scoreboard *sb)
 		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),
+				oid_to_hex(&ent->suspect->commit->object.oid),
 				ent->suspect->refcnt);
 			baa = 1;
 		}
@@ -2152,16 +2181,6 @@ static void sanity_check_refcnt(struct scoreboard *sb)
 	}
 }
 
-/*
- * 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;
@@ -2186,13 +2205,23 @@ static int git_blame_config(const char *var, const char *value, void *cb)
 		blank_boundary = git_config_bool(var, value);
 		return 0;
 	}
+	if (!strcmp(var, "blame.showemail")) {
+		int *output_option = cb;
+		if (git_config_bool(var, value))
+			*output_option |= OUTPUT_SHOW_EMAIL;
+		else
+			*output_option &= ~OUTPUT_SHOW_EMAIL;
+		return 0;
+	}
 	if (!strcmp(var, "blame.date")) {
 		if (!value)
 			return config_error_nonbool(var);
-		blame_date_mode = parse_date_format(value);
+		parse_date_format(value, &blame_date_mode);
 		return 0;
 	}
 
+	if (git_diff_heuristic_config(var, value, cb) < 0)
+		return -1;
 	if (userdiff_config(var, value) < 0)
 		return -1;
 
@@ -2202,47 +2231,55 @@ static int git_blame_config(const char *var, const char *value, void *cb)
 static void verify_working_tree_path(struct commit *work_tree, const char *path)
 {
 	struct commit_list *parents;
+	int pos;
 
 	for (parents = work_tree->parents; parents; parents = parents->next) {
-		const unsigned char *commit_sha1 = parents->item->object.sha1;
-		unsigned char blob_sha1[20];
+		const struct object_id *commit_oid = &parents->item->object.oid;
+		struct object_id blob_oid;
 		unsigned mode;
 
-		if (!get_tree_entry(commit_sha1, path, blob_sha1, &mode) &&
-		    sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
+		if (!get_tree_entry(commit_oid->hash, path, blob_oid.hash, &mode) &&
+		    sha1_object_info(blob_oid.hash, NULL) == OBJ_BLOB)
 			return;
 	}
-	die("no such path '%s' in HEAD", path);
+
+	pos = cache_name_pos(path, strlen(path));
+	if (pos >= 0)
+		; /* path is in the index */
+	else if (-1 - pos < active_nr &&
+		 !strcmp(active_cache[-1 - pos]->name, path))
+		; /* path is in the index, unmerged */
+	else
+		die("no such path '%s' in HEAD", path);
 }
 
-static struct commit_list **append_parent(struct commit_list **tail, const unsigned char *sha1)
+static struct commit_list **append_parent(struct commit_list **tail, const struct object_id *oid)
 {
 	struct commit *parent;
 
-	parent = lookup_commit_reference(sha1);
+	parent = lookup_commit_reference(oid->hash);
 	if (!parent)
-		die("no such commit %s", sha1_to_hex(sha1));
+		die("no such commit %s", oid_to_hex(oid));
 	return &commit_list_insert(parent, tail)->next;
 }
 
 static void append_merge_parents(struct commit_list **tail)
 {
 	int merge_head;
-	const char *merge_head_file = git_path("MERGE_HEAD");
 	struct strbuf line = STRBUF_INIT;
 
-	merge_head = open(merge_head_file, O_RDONLY);
+	merge_head = open(git_path_merge_head(), O_RDONLY);
 	if (merge_head < 0) {
 		if (errno == ENOENT)
 			return;
-		die("cannot open '%s' for reading", merge_head_file);
+		die("cannot open '%s' for reading", git_path_merge_head());
 	}
 
 	while (!strbuf_getwholeline_fd(&line, merge_head, '\n')) {
-		unsigned char sha1[20];
-		if (line.len < 40 || get_sha1_hex(line.buf, sha1))
-			die("unknown line in '%s': %s", merge_head_file, line.buf);
-		tail = append_parent(tail, sha1);
+		struct object_id oid;
+		if (line.len < GIT_SHA1_HEXSZ || get_oid_hex(line.buf, &oid))
+			die("unknown line in '%s': %s", git_path_merge_head(), line.buf);
+		tail = append_parent(tail, &oid);
 	}
 	close(merge_head);
 	strbuf_release(&line);
@@ -2271,7 +2308,7 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
 	struct commit *commit;
 	struct origin *origin;
 	struct commit_list **parent_tail, *parent;
-	unsigned char head_sha1[20];
+	struct object_id head_oid;
 	struct strbuf buf = STRBUF_INIT;
 	const char *ident;
 	time_t now;
@@ -2280,16 +2317,17 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
 	unsigned mode;
 	struct strbuf msg = STRBUF_INIT;
 
+	read_cache();
 	time(&now);
 	commit = alloc_commit_node();
 	commit->object.parsed = 1;
 	commit->date = now;
 	parent_tail = &commit->parents;
 
-	if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_sha1, NULL))
+	if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_oid.hash, NULL))
 		die("no such ref: HEAD");
 
-	parent_tail = append_parent(parent_tail, head_sha1);
+	parent_tail = append_parent(parent_tail, &head_oid);
 	append_merge_parents(parent_tail);
 	verify_working_tree_path(commit, path);
 
@@ -2299,7 +2337,7 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
 	strbuf_addstr(&msg, "tree 0000000000000000000000000000000000000000\n");
 	for (parent = commit->parents; parent; parent = parent->next)
 		strbuf_addf(&msg, "parent %s\n",
-			    sha1_to_hex(parent->item->object.sha1));
+			    oid_to_hex(&parent->item->object.oid));
 	strbuf_addf(&msg,
 		    "author %s\n"
 		    "committer %s\n\n"
@@ -2330,7 +2368,7 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
 		switch (st.st_mode & S_IFMT) {
 		case S_IFREG:
 			if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
-			    textconv_object(read_from, mode, null_sha1, 0, &buf_ptr, &buf_len))
+			    textconv_object(read_from, mode, &null_oid, 0, &buf_ptr, &buf_len))
 				strbuf_attach(&buf, buf_ptr, buf_len, buf_len + 1);
 			else if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
 				die_errno("cannot open or read '%s'", read_from);
@@ -2349,9 +2387,10 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
 		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);
+	pretend_sha1_file(buf.buf, buf.len, OBJ_BLOB, origin->blob_oid.hash);
 
 	/*
 	 * Read the current index, replace the path entry with
@@ -2373,52 +2412,86 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
 	}
 	size = cache_entry_size(len);
 	ce = xcalloc(1, size);
-	hashcpy(ce->sha1, origin->blob_sha1);
+	oidcpy(&ce->oid, &origin->blob_oid);
 	memcpy(ce->name, path, len);
 	ce->ce_flags = create_ce_flags(0);
 	ce->ce_namelen = len;
 	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(&the_index, path);
 
 	return commit;
 }
 
-static const char *prepare_final(struct scoreboard *sb)
+static struct commit *find_single_final(struct rev_info *revs,
+					const char **name_p)
 {
 	int i;
-	const char *final_commit_name = NULL;
-	struct rev_info *revs = sb->revs;
+	struct commit *found = NULL;
+	const char *name = NULL;
 
-	/*
-	 * 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);
+		obj = deref_tag(obj, NULL, 0);
 		if (obj->type != OBJ_COMMIT)
 			die("Non commit %s?", revs->pending.objects[i].name);
-		if (sb->final)
+		if (found)
 			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;
+			    revs->pending.objects[i].name, name);
+		found = (struct commit *)obj;
+		name = revs->pending.objects[i].name;
 	}
-	return final_commit_name;
+	if (name_p)
+		*name_p = name;
+	return found;
+}
+
+static char *prepare_final(struct scoreboard *sb)
+{
+	const char *name;
+	sb->final = find_single_final(sb->revs, &name);
+	return xstrdup_or_null(name);
 }
 
-static const char *prepare_initial(struct scoreboard *sb)
+static const char *dwim_reverse_initial(struct scoreboard *sb)
+{
+	/*
+	 * DWIM "git blame --reverse ONE -- PATH" as
+	 * "git blame --reverse ONE..HEAD -- PATH" but only do so
+	 * when it makes sense.
+	 */
+	struct object *obj;
+	struct commit *head_commit;
+	unsigned char head_sha1[20];
+
+	if (sb->revs->pending.nr != 1)
+		return NULL;
+
+	/* Is that sole rev a committish? */
+	obj = sb->revs->pending.objects[0].item;
+	obj = deref_tag(obj, NULL, 0);
+	if (obj->type != OBJ_COMMIT)
+		return NULL;
+
+	/* Do we have HEAD? */
+	if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_sha1, NULL))
+		return NULL;
+	head_commit = lookup_commit_reference_gently(head_sha1, 1);
+	if (!head_commit)
+		return NULL;
+
+	/* Turn "ONE" into "ONE..HEAD" then */
+	obj->flags |= UNINTERESTING;
+	add_pending_object(sb->revs, &head_commit->object, "HEAD");
+
+	sb->final = (struct commit *)obj;
+	return sb->revs->pending.objects[0].name;
+}
+
+static char *prepare_initial(struct scoreboard *sb)
 {
 	int i;
 	const char *final_commit_name = NULL;
@@ -2432,20 +2505,22 @@ static const char *prepare_initial(struct scoreboard *sb)
 		struct object *obj = revs->pending.objects[i].item;
 		if (!(obj->flags & UNINTERESTING))
 			continue;
-		while (obj->type == OBJ_TAG)
-			obj = deref_tag(obj, NULL, 0);
+		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?",
+			die("More than one commit to dig up 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;
 	}
+
+	if (!final_commit_name)
+		final_commit_name = dwim_reverse_initial(sb);
 	if (!final_commit_name)
-		die("No commit to dig down to?");
-	return final_commit_name;
+		die("No commit to dig up from?");
+	return xstrdup(final_commit_name);
 }
 
 static int blame_copy_callback(const struct option *option, const char *arg, int unset)
@@ -2489,19 +2564,21 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 	struct origin *o;
 	struct blame_entry *ent = NULL;
 	long dashdash_pos, lno;
-	const char *final_commit_name = NULL;
+	char *final_commit_name = NULL;
 	enum object_type type;
-
-	static struct string_list range_list;
-	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[] = {
+	struct commit *final_commit = NULL;
+
+	struct string_list range_list = STRING_LIST_INIT_NODUP;
+	int output_option = 0, opt = 0;
+	int show_stats = 0;
+	const char *revs_file = NULL;
+	const char *contents_from = NULL;
+	const struct option options[] = {
 		OPT_BOOL(0, "incremental", &incremental, N_("Show blame entries as we find them, incrementally")),
 		OPT_BOOL('b', NULL, &blank_boundary, N_("Show blank SHA-1 for boundary commits (Default: off)")),
 		OPT_BOOL(0, "root", &show_root, N_("Do not treat root commits as boundaries (Default: off)")),
 		OPT_BOOL(0, "show-stats", &show_stats, N_("Show work cost statistics")),
+		OPT_BOOL(0, "progress", &show_progress, N_("Force progress reporting")),
 		OPT_BIT(0, "score-debug", &output_option, N_("Show output score for blame entries"), OUTPUT_SHOW_SCORE),
 		OPT_BIT('f', "show-name", &output_option, N_("Show original filename (Default: auto)"), OUTPUT_SHOW_NAME),
 		OPT_BIT('n', "show-number", &output_option, N_("Show original linenumber (Default: off)"), OUTPUT_SHOW_NUMBER),
@@ -2513,6 +2590,15 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 		OPT_BIT('s', NULL, &output_option, N_("Suppress author name and timestamp (Default: off)"), OUTPUT_NO_AUTHOR),
 		OPT_BIT('e', "show-email", &output_option, N_("Show author email instead of name (Default: off)"), OUTPUT_SHOW_EMAIL),
 		OPT_BIT('w', NULL, &xdl_opts, N_("Ignore whitespace differences"), XDF_IGNORE_WHITESPACE),
+
+		/*
+		 * The following two options are parsed by parse_revision_opt()
+		 * and are only included here to get included in the "-h"
+		 * output:
+		 */
+		{ OPTION_LOWLEVEL_CALLBACK, 0, "indent-heuristic", NULL, NULL, N_("Use an experimental indent-based heuristic to improve diffs"), PARSE_OPT_NOARG, parse_opt_unknown_cb },
+		{ OPTION_LOWLEVEL_CALLBACK, 0, "compaction-heuristic", NULL, NULL, N_("Use an experimental blank-line-based heuristic to improve diffs"), PARSE_OPT_NOARG, parse_opt_unknown_cb },
+
 		OPT_BIT(0, "minimal", &xdl_opts, N_("Spend extra cycles to find better match"), XDF_NEED_MINIMAL),
 		OPT_STRING('S', NULL, &revs_file, N_("file"), N_("Use revisions from <file> instead of calling git-rev-list")),
 		OPT_STRING(0, "contents", &contents_from, N_("file"), N_("Use <file>'s contents as the final image")),
@@ -2529,7 +2615,7 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 	unsigned int range_i;
 	long anchor;
 
-	git_config(git_blame_config, NULL);
+	git_config(git_blame_config, &output_option);
 	init_revisions(&revs, NULL);
 	revs.date_mode = blame_date_mode;
 	DIFF_OPT_SET(&revs.diffopt, ALLOW_TEXTCONV);
@@ -2537,6 +2623,7 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 
 	save_commit_buffer = 0;
 	dashdash_pos = 0;
+	show_progress = -1;
 
 	parse_options_start(&ctx, argc, argv, prefix, options,
 			    PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_ARGV0);
@@ -2558,9 +2645,17 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 	}
 parse_done:
 	no_whole_file_rename = !DIFF_OPT_TST(&revs.diffopt, FOLLOW_RENAMES);
+	xdl_opts |= revs.diffopt.xdl_opts & (XDF_COMPACTION_HEURISTIC | XDF_INDENT_HEURISTIC);
 	DIFF_OPT_CLR(&revs.diffopt, FOLLOW_RENAMES);
 	argc = parse_options_end(&ctx);
 
+	if (incremental || (output_option & OUTPUT_PORCELAIN)) {
+		if (show_progress > 0)
+			die(_("--progress can't be used with --incremental or porcelain formats"));
+		show_progress = 0;
+	} else if (show_progress < 0)
+		show_progress = isatty(2);
+
 	if (0 < abbrev)
 		/* one more abbrev length is needed for the boundary commit */
 		abbrev++;
@@ -2570,13 +2665,13 @@ parse_done:
 
 	if (cmd_is_annotate) {
 		output_option |= OUTPUT_ANNOTATE_COMPAT;
-		blame_date_mode = DATE_ISO8601;
+		blame_date_mode.type = DATE_ISO8601;
 	} else {
 		blame_date_mode = revs.date_mode;
 	}
 
 	/* The maximum width used to show the dates */
-	switch (blame_date_mode) {
+	switch (blame_date_mode.type) {
 	case DATE_RFC2822:
 		blame_date_width = sizeof("Thu, 19 Oct 2006 16:00:04 -0700");
 		break;
@@ -2589,6 +2684,9 @@ parse_done:
 	case DATE_RAW:
 		blame_date_width = sizeof("1161298804 -0700");
 		break;
+	case DATE_UNIX:
+		blame_date_width = sizeof("1161298804");
+		break;
 	case DATE_SHORT:
 		blame_date_width = sizeof("2006-10-19");
 		break;
@@ -2601,10 +2699,12 @@ parse_done:
 		   fewer display columns. */
 		blame_date_width = utf8_strwidth(_("4 years, 11 months ago")) + 1; /* add the null */
 		break;
-	case DATE_LOCAL:
 	case DATE_NORMAL:
 		blame_date_width = sizeof("Thu Oct 19 16:00:04 2006 -0700");
 		break;
+	case DATE_STRFTIME:
+		blame_date_width = strlen(show_date(0, 0, &blame_date_mode)) + 1; /* add the null */
+		break;
 	}
 	blame_date_width -= 1; /* strip the null */
 
@@ -2656,14 +2756,14 @@ parse_done:
 		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) */
+		if (argc == 3 && !file_exists(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))
+		if (!file_exists(path))
 			die_errno("cannot stat path '%s'", path);
 	}
 
@@ -2677,10 +2777,12 @@ parse_done:
 		sb.commits.compare = compare_commits_by_commit_date;
 	}
 	else if (contents_from)
-		die("--contents and --children do not blend well.");
+		die(_("--contents and --reverse do not blend well."));
 	else {
 		final_commit_name = prepare_initial(&sb);
 		sb.commits.compare = compare_commits_by_reverse_commit_date;
+		if (revs.first_parent_only)
+			revs.children.name = NULL;
 	}
 
 	if (!sb.final) {
@@ -2695,7 +2797,13 @@ parse_done:
 		add_pending_object(&revs, &(sb.final->object), ":");
 	}
 	else if (contents_from)
-		die("Cannot use --contents with final commit object name");
+		die(_("cannot use --contents with final commit object name"));
+
+	if (reverse && revs.first_parent_only) {
+		final_commit = find_single_final(sb.revs, NULL);
+		if (!final_commit)
+			die(_("--reverse and --first-parent together require specified latest commit"));
+	}
 
 	/*
 	 * If we have bottom, this will mark the ancestors of the
@@ -2705,7 +2813,26 @@ parse_done:
 	if (prepare_revision_walk(&revs))
 		die(_("revision walk setup failed"));
 
-	if (is_null_sha1(sb.final->object.sha1)) {
+	if (reverse && revs.first_parent_only) {
+		struct commit *c = final_commit;
+
+		sb.revs->children.name = "children";
+		while (c->parents &&
+		       oidcmp(&c->object.oid, &sb.final->object.oid)) {
+			struct commit_list *l = xcalloc(1, sizeof(*l));
+
+			l->item = c;
+			if (add_decoration(&sb.revs->children,
+					   &c->parents->item->object, l))
+				die("BUG: not unique item in first-parent chain");
+			c = c->parents->item;
+		}
+
+		if (oidcmp(&c->object.oid, &sb.final->object.oid))
+			die(_("--reverse --first-parent together require range along first-parent chain"));
+	}
+
+	if (is_null_oid(&sb.final->object.oid)) {
 		o = sb.final->util;
 		sb.final_buf = xmemdupz(o->file.ptr, o->file.size);
 		sb.final_buf_size = o->file.size;
@@ -2713,26 +2840,26 @@ parse_done:
 	else {
 		o = get_origin(&sb, sb.final, path);
 		if (fill_blob_sha1_and_mode(o))
-			die("no such path %s in %s", path, final_commit_name);
+			die(_("no such path %s in %s"), path, final_commit_name);
 
 		if (DIFF_OPT_TST(&sb.revs->diffopt, ALLOW_TEXTCONV) &&
-		    textconv_object(path, o->mode, o->blob_sha1, 1, (char **) &sb.final_buf,
+		    textconv_object(path, o->mode, &o->blob_oid, 1, (char **) &sb.final_buf,
 				    &sb.final_buf_size))
 			;
 		else
-			sb.final_buf = read_sha1_file(o->blob_sha1, &type,
+			sb.final_buf = read_sha1_file(o->blob_oid.hash, &type,
 						      &sb.final_buf_size);
 
 		if (!sb.final_buf)
-			die("Cannot read blob %s for path %s",
-			    sha1_to_hex(o->blob_sha1),
+			die(_("cannot read blob %s for path %s"),
+			    oid_to_hex(&o->blob_oid),
 			    path);
 	}
 	num_read_blob++;
 	lno = prepare_lines(&sb);
 
 	if (lno && !range_list.nr)
-		string_list_append(&range_list, xstrdup("1"));
+		string_list_append(&range_list, "1");
 
 	anchor = 1;
 	range_set_init(&ranges, range_list.nr);
@@ -2743,7 +2870,9 @@ parse_done:
 				    &bottom, &top, sb.path))
 			usage(blame_usage);
 		if (lno < top || ((lno || bottom) && lno < bottom))
-			die("file %s has only %lu lines", path, lno);
+			die(Q_("file %s has only %lu line",
+			       "file %s has only %lu lines",
+			       lno), path, lno);
 		if (bottom < 1)
 			bottom = 1;
 		if (top < 1)
@@ -2781,10 +2910,12 @@ parse_done:
 
 	read_mailmap(&mailmap, NULL);
 
+	assign_blame(&sb, opt);
+
 	if (!incremental)
 		setup_pager();
 
-	assign_blame(&sb, opt);
+	free(final_commit_name);
 
 	if (incremental)
 		return 0;