1 files changed, 100 insertions, 48 deletions

diff --git a/builtin/blame.c b/builtin/blame.c
index f618392e55..4ddfadb71f 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -120,7 +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
@@ -154,8 +154,8 @@ static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b,
  */
 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)
 {
@@ -163,7 +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);
@@ -188,15 +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;
 	}
@@ -508,17 +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.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;
 }
@@ -572,7 +573,7 @@ static struct origin *find_origin(struct scoreboard *sb,
 	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 {
 		/*
@@ -598,7 +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->oid.hash);
+			oidcpy(&porigin->blob_oid, &p->one->oid);
 			porigin->mode = p->one->mode;
 			break;
 		case 'A':
@@ -644,7 +645,7 @@ 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->oid.hash);
+			oidcpy(&porigin->blob_oid, &p->one->oid);
 			porigin->mode = p->one->mode;
 			break;
 		}
@@ -1308,7 +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->oid.hash);
+			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)
@@ -1458,15 +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;
 				}
@@ -1941,7 +1941,7 @@ static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
 	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)
@@ -2220,6 +2220,8 @@ static int git_blame_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
+	if (git_diff_heuristic_config(var, value, cb) < 0)
+		return -1;
 	if (userdiff_config(var, value) < 0)
 		return -1;
 
@@ -2232,12 +2234,12 @@ static void verify_working_tree_path(struct commit *work_tree, const char *path)
 	int pos;
 
 	for (parents = work_tree->parents; parents; parents = parents->next) {
-		const unsigned char *commit_sha1 = parents->item->object.oid.hash;
-		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;
 	}
 
@@ -2251,13 +2253,13 @@ static void verify_working_tree_path(struct commit *work_tree, const char *path)
 		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;
 }
 
@@ -2274,10 +2276,10 @@ static void append_merge_parents(struct commit_list **tail)
 	}
 
 	while (!strbuf_getwholeline_fd(&line, merge_head, '\n')) {
-		unsigned char sha1[20];
-		if (line.len < 40 || get_sha1_hex(line.buf, 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, sha1);
+		tail = append_parent(tail, &oid);
 	}
 	close(merge_head);
 	strbuf_release(&line);
@@ -2306,7 +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;
@@ -2322,10 +2324,10 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
 	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);
 
@@ -2366,7 +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);
@@ -2388,7 +2390,7 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
 	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
@@ -2410,7 +2412,7 @@ 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;
@@ -2454,6 +2456,41 @@ static char *prepare_final(struct scoreboard *sb)
 	return xstrdup_or_null(name);
 }
 
+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;
@@ -2472,14 +2509,17 @@ static char *prepare_initial(struct scoreboard *sb)
 		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?");
+		die("No commit to dig up from?");
 	return xstrdup(final_commit_name);
 }
 
@@ -2550,6 +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")),
@@ -2596,12 +2645,13 @@ 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");
+			die(_("--progress can't be used with --incremental or porcelain formats"));
 		show_progress = 0;
 	} else if (show_progress < 0)
 		show_progress = isatty(2);
@@ -2727,7 +2777,7 @@ parse_done:
 		sb.commits.compare = compare_commits_by_commit_date;
 	}
 	else if (contents_from)
-		die("--contents and --reverse 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;
@@ -2747,12 +2797,12 @@ 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");
+			die(_("--reverse and --first-parent together require specified latest commit"));
 	}
 
 	/*
@@ -2779,7 +2829,7 @@ parse_done:
 		}
 
 		if (oidcmp(&c->object.oid, &sb.final->object.oid))
-			die("--reverse --first-parent together require range along first-parent chain");
+			die(_("--reverse --first-parent together require range along first-parent chain"));
 	}
 
 	if (is_null_oid(&sb.final->object.oid)) {
@@ -2790,19 +2840,19 @@ 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++;
@@ -2820,7 +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)