From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 8 Apr 2014 19:00:32 +0000 (-0700)
Subject: Merge branch 'jk/pack-bitmap'
X-Git-Tag: v2.0.0-rc0~13
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/967f8c918465312cc6cc1bcbcfacafcf95152bd8?ds=inline;hp=-c

Merge branch 'jk/pack-bitmap'

* jk/pack-bitmap:
pack-objects: do not reuse packfiles without --delta-base-offset
add `ignore_missing_links` mode to revwalk
---

967f8c918465312cc6cc1bcbcfacafcf95152bd8
diff --combined builtin/pack-objects.c
index c1f4310871,c7590cb65a..de36c60ca1
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@@ -708,7 -708,7 +708,7 @@@ static struct object_entry **compute_wr
  static off_t write_reused_pack(struct sha1file *f)
  {
  	unsigned char buffer[8192];
 -	off_t to_write;
 +	off_t to_write, total;
  	int fd;
  
  	if (!is_pack_valid(reuse_packfile))
@@@ -725,7 -725,7 +725,7 @@@
  	if (reuse_packfile_offset < 0)
  		reuse_packfile_offset = reuse_packfile->pack_size - 20;
  
 -	to_write = reuse_packfile_offset - sizeof(struct pack_header);
 +	total = to_write = reuse_packfile_offset - sizeof(struct pack_header);
  
  	while (to_write) {
  		int read_pack = xread(fd, buffer, sizeof(buffer));
@@@ -738,23 -738,10 +738,23 @@@
  
  		sha1write(f, buffer, read_pack);
  		to_write -= read_pack;
 +
 +		/*
 +		 * We don't know the actual number of objects written,
 +		 * only how many bytes written, how many bytes total, and
 +		 * how many objects total. So we can fake it by pretending all
 +		 * objects we are writing are the same size. This gives us a
 +		 * smooth progress meter, and at the end it matches the true
 +		 * answer.
 +		 */
 +		written = reuse_packfile_objects *
 +				(((double)(total - to_write)) / total);
 +		display_progress(progress_state, written);
  	}
  
  	close(fd);
 -	written += reuse_packfile_objects;
 +	written = reuse_packfile_objects;
 +	display_progress(progress_state, written);
  	return reuse_packfile_offset - sizeof(struct pack_header);
  }
  
@@@ -768,7 -755,7 +768,7 @@@ static void write_pack_file(void
  	struct object_entry **write_order;
  
  	if (progress > pack_to_stdout)
 -		progress_state = start_progress("Writing objects", nr_result);
 +		progress_state = start_progress(_("Writing objects"), nr_result);
  	written_list = xmalloc(to_pack.nr_objects * sizeof(*written_list));
  	write_order = compute_write_order();
  
@@@ -782,6 -769,8 +782,6 @@@
  			f = create_tmp_packfile(&pack_tmp_name);
  
  		offset = write_pack_header(f, nr_remaining);
 -		if (!offset)
 -			die_errno("unable to write pack header");
  
  		if (reuse_packfile) {
  			off_t packfile_size;
@@@ -816,7 -805,7 +816,7 @@@
  
  		if (!pack_to_stdout) {
  			struct stat st;
 -			char tmpname[PATH_MAX];
 +			struct strbuf tmpname = STRBUF_INIT;
  
  			/*
  			 * Packs are runtime accessed in their mtime
@@@ -836,22 -825,26 +836,22 @@@
  				utb.modtime = --last_mtime;
  				if (utime(pack_tmp_name, &utb) < 0)
  					warning("failed utime() on %s: %s",
 -						tmpname, strerror(errno));
 +						pack_tmp_name, strerror(errno));
  			}
  
 -			/* Enough space for "-<sha-1>.pack"? */
 -			if (sizeof(tmpname) <= strlen(base_name) + 50)
 -				die("pack base name '%s' too long", base_name);
 -			snprintf(tmpname, sizeof(tmpname), "%s-", base_name);
 +			strbuf_addf(&tmpname, "%s-", base_name);
  
  			if (write_bitmap_index) {
  				bitmap_writer_set_checksum(sha1);
  				bitmap_writer_build_type_index(written_list, nr_written);
  			}
  
 -			finish_tmp_packfile(tmpname, pack_tmp_name,
 +			finish_tmp_packfile(&tmpname, pack_tmp_name,
  					    written_list, nr_written,
  					    &pack_idx_opts, sha1);
  
  			if (write_bitmap_index) {
 -				char *end_of_name_prefix = strrchr(tmpname, 0);
 -				sprintf(end_of_name_prefix, "%s.bitmap", sha1_to_hex(sha1));
 +				strbuf_addf(&tmpname, "%s.bitmap", sha1_to_hex(sha1));
  
  				stop_progress(&progress_state);
  
@@@ -860,11 -853,10 +860,11 @@@
  				bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
  				bitmap_writer_build(&to_pack);
  				bitmap_writer_finish(written_list, nr_written,
 -						     tmpname, write_bitmap_options);
 +						     tmpname.buf, write_bitmap_options);
  				write_bitmap_index = 0;
  			}
  
 +			strbuf_release(&tmpname);
  			free(pack_tmp_name);
  			puts(sha1_to_hex(sha1));
  		}
@@@ -1035,7 -1027,7 +1035,7 @@@ static int add_object_entry(const unsig
  			    exclude, name && no_try_delta(name),
  			    index_pos, found_pack, found_offset);
  
 -	display_progress(progress_state, to_pack.nr_objects);
 +	display_progress(progress_state, nr_result);
  	return 1;
  }
  
@@@ -1051,7 -1043,7 +1051,7 @@@ static int add_object_entry_from_bitmap
  
  	create_object_entry(sha1, type, name_hash, 0, 0, index_pos, pack, offset);
  
 -	display_progress(progress_state, to_pack.nr_objects);
 +	display_progress(progress_state, nr_result);
  	return 1;
  }
  
@@@ -1076,7 -1068,7 +1076,7 @@@ static int pbase_tree_cache_ix_incr(in
  static struct pbase_tree {
  	struct pbase_tree *next;
  	/* This is a phony "cache" entry; we are not
 -	 * going to evict it nor find it through _get()
 +	 * going to evict it or find it through _get()
  	 * mechanism -- this is for the toplevel node that
  	 * would almost always change with any commit.
  	 */
@@@ -1233,9 -1225,12 +1233,9 @@@ static int check_pbase_path(unsigned ha
  	if (0 <= pos)
  		return 1;
  	pos = -pos - 1;
 -	if (done_pbase_paths_alloc <= done_pbase_paths_num) {
 -		done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
 -		done_pbase_paths = xrealloc(done_pbase_paths,
 -					    done_pbase_paths_alloc *
 -					    sizeof(unsigned));
 -	}
 +	ALLOC_GROW(done_pbase_paths,
 +		   done_pbase_paths_num + 1,
 +		   done_pbase_paths_alloc);
  	done_pbase_paths_num++;
  	if (pos < done_pbase_paths_num)
  		memmove(done_pbase_paths + pos + 1,
@@@ -2104,7 -2099,7 +2104,7 @@@ static int add_ref_tag(const char *path
  {
  	unsigned char peeled[20];
  
 -	if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
 +	if (starts_with(path, "refs/tags/") && /* is a tag? */
  	    !peel_ref(path, peeled)        && /* peelable? */
  	    packlist_find(&to_pack, peeled, NULL))      /* object packed? */
  		add_object_entry(sha1, OBJ_TAG, NULL, 0);
@@@ -2171,7 -2166,7 +2171,7 @@@ static void prepare_pack(int window, in
  	if (nr_deltas && n > 1) {
  		unsigned nr_done = 0;
  		if (progress)
 -			progress_state = start_progress("Compressing objects",
 +			progress_state = start_progress(_("Compressing objects"),
  							nr_deltas);
  		qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
  		ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
@@@ -2439,18 -2434,34 +2439,29 @@@ static void loosen_unused_packed_object
  	}
  }
  
+ /*
+  * This tracks any options which a reader of the pack might
+  * not understand, and which would therefore prevent blind reuse
+  * of what we have on disk.
+  */
+ static int pack_options_allow_reuse(void)
+ {
+ 	return allow_ofs_delta;
+ }
+ 
  static int get_object_list_from_bitmap(struct rev_info *revs)
  {
  	if (prepare_bitmap_walk(revs) < 0)
  		return -1;
  
- 	if (!reuse_partial_packfile_from_bitmap(
+ 	if (pack_options_allow_reuse() &&
+ 	    !reuse_partial_packfile_from_bitmap(
  			&reuse_packfile,
  			&reuse_packfile_objects,
  			&reuse_packfile_offset)) {
  		assert(reuse_packfile_objects);
  		nr_result += reuse_packfile_objects;
 -
 -		if (progress) {
 -			fprintf(stderr, "Reusing existing pack: %d, done.\n",
 -				reuse_packfile_objects);
 -			fflush(stderr);
 -		}
 +		display_progress(progress_state, nr_result);
  	}
  
  	traverse_bitmap_commit_list(&add_object_entry_from_bitmap);
@@@ -2467,9 -2478,6 +2478,9 @@@ static void get_object_list(int ac, con
  	save_commit_buffer = 0;
  	setup_revisions(ac, av, &revs, NULL);
  
 +	/* make sure shallows are read */
 +	is_repository_shallow();
 +
  	while (fgets(line, sizeof(line), stdin) != NULL) {
  		int len = strlen(line);
  		if (len && line[len - 1] == '\n')
@@@ -2482,13 -2490,6 +2493,13 @@@
  				write_bitmap_index = 0;
  				continue;
  			}
 +			if (starts_with(line, "--shallow ")) {
 +				unsigned char sha1[20];
 +				if (get_sha1_hex(line + 10, sha1))
 +					die("not an SHA-1 '%s'", line + 10);
 +				register_shallow(sha1);
 +				continue;
 +			}
  			die("not a rev '%s'", line);
  		}
  		if (handle_revision_arg(line, &revs, flags, REVARG_CANNOT_BE_FILENAME))
@@@ -2634,7 -2635,7 +2645,7 @@@ int cmd_pack_objects(int argc, const ch
  		OPT_END(),
  	};
  
 -	read_replace_refs = 0;
 +	check_replace_refs = 0;
  
  	reset_pack_idx_option(&pack_idx_opts);
  	git_config(git_pack_config, NULL);
@@@ -2709,7 -2710,7 +2720,7 @@@
  	prepare_packed_git();
  
  	if (progress)
 -		progress_state = start_progress("Counting objects", 0);
 +		progress_state = start_progress(_("Counting objects"), 0);
  	if (!use_internal_rev_list)
  		read_object_list_from_stdin();
  	else {
diff --combined list-objects.c
index 206816fa9c,b2db6ba0d3..3595ee7a22
--- a/list-objects.c
+++ b/list-objects.c
@@@ -81,8 -81,11 +81,11 @@@ static void process_tree(struct rev_inf
  		die("bad tree object");
  	if (obj->flags & (UNINTERESTING | SEEN))
  		return;
- 	if (parse_tree(tree) < 0)
+ 	if (parse_tree(tree) < 0) {
+ 		if (revs->ignore_missing_links)
+ 			return;
  		die("bad tree object %s", sha1_to_hex(obj->sha1));
+ 	}
  	obj->flags |= SEEN;
  	show(obj, path, name, cb_data);
  	me.up = path;
@@@ -162,17 -165,15 +165,17 @@@ void mark_edges_uninteresting(struct re
  		}
  		mark_edge_parents_uninteresting(commit, revs, show_edge);
  	}
 -	for (i = 0; i < revs->cmdline.nr; i++) {
 -		struct object *obj = revs->cmdline.rev[i].item;
 -		struct commit *commit = (struct commit *)obj;
 -		if (obj->type != OBJ_COMMIT || !(obj->flags & UNINTERESTING))
 -			continue;
 -		mark_tree_uninteresting(commit->tree);
 -		if (revs->edge_hint && !(obj->flags & SHOWN)) {
 -			obj->flags |= SHOWN;
 -			show_edge(commit);
 +	if (revs->edge_hint) {
 +		for (i = 0; i < revs->cmdline.nr; i++) {
 +			struct object *obj = revs->cmdline.rev[i].item;
 +			struct commit *commit = (struct commit *)obj;
 +			if (obj->type != OBJ_COMMIT || !(obj->flags & UNINTERESTING))
 +				continue;
 +			mark_tree_uninteresting(commit->tree);
 +			if (!(obj->flags & SHOWN)) {
 +				obj->flags |= SHOWN;
 +				show_edge(commit);
 +			}
  		}
  	}
  }
diff --combined revision.c
index 794a8835c0,520b3e7df6..71e2337423
--- a/revision.c
+++ b/revision.c
@@@ -16,7 -16,6 +16,7 @@@
  #include "line-log.h"
  #include "mailmap.h"
  #include "commit-slab.h"
 +#include "dir.h"
  
  volatile show_early_output_fn_t show_early_output;
  
@@@ -105,12 -104,17 +105,12 @@@ static void mark_blob_uninteresting(str
  	blob->object.flags |= UNINTERESTING;
  }
  
 -void mark_tree_uninteresting(struct tree *tree)
 +static void mark_tree_contents_uninteresting(struct tree *tree)
  {
  	struct tree_desc desc;
  	struct name_entry entry;
  	struct object *obj = &tree->object;
  
 -	if (!tree)
 -		return;
 -	if (obj->flags & UNINTERESTING)
 -		return;
 -	obj->flags |= UNINTERESTING;
  	if (!has_sha1_file(obj->sha1))
  		return;
  	if (parse_tree(tree) < 0)
@@@ -138,18 -142,6 +138,18 @@@
  	free_tree_buffer(tree);
  }
  
 +void mark_tree_uninteresting(struct tree *tree)
 +{
 +	struct object *obj = &tree->object;
 +
 +	if (!tree)
 +		return;
 +	if (obj->flags & UNINTERESTING)
 +		return;
 +	obj->flags |= UNINTERESTING;
 +	mark_tree_contents_uninteresting(tree);
 +}
 +
  void mark_parents_uninteresting(struct commit *commit)
  {
  	struct commit_list *parents = NULL, *l;
@@@ -284,7 -276,6 +284,7 @@@ static struct commit *handle_commit(str
  				return NULL;
  			die("bad object %s", sha1_to_hex(tag->tagged->sha1));
  		}
 +		object->flags |= flags;
  	}
  
  	/*
@@@ -296,6 -287,7 +296,6 @@@
  		if (parse_commit(commit) < 0)
  			die("unable to parse commit %s", name);
  		if (flags & UNINTERESTING) {
 -			commit->object.flags |= UNINTERESTING;
  			mark_parents_uninteresting(commit);
  			revs->limited = 1;
  		}
@@@ -313,7 -305,7 +313,7 @@@
  		if (!revs->tree_objects)
  			return NULL;
  		if (flags & UNINTERESTING) {
 -			mark_tree_uninteresting(tree);
 +			mark_tree_contents_uninteresting(tree);
  			return NULL;
  		}
  		add_pending_object(revs, object, "");
@@@ -324,10 -316,13 +324,10 @@@
  	 * Blob object? You know the drill by now..
  	 */
  	if (object->type == OBJ_BLOB) {
 -		struct blob *blob = (struct blob *)object;
  		if (!revs->blob_objects)
  			return NULL;
 -		if (flags & UNINTERESTING) {
 -			mark_blob_uninteresting(blob);
 +		if (flags & UNINTERESTING)
  			return NULL;
 -		}
  		add_pending_object(revs, object, "");
  		return NULL;
  	}
@@@ -497,14 -492,24 +497,14 @@@ static int rev_compare_tree(struct rev_
  static int rev_same_tree_as_empty(struct rev_info *revs, struct commit *commit)
  {
  	int retval;
 -	void *tree;
 -	unsigned long size;
 -	struct tree_desc empty, real;
  	struct tree *t1 = commit->tree;
  
  	if (!t1)
  		return 0;
  
 -	tree = read_object_with_reference(t1->object.sha1, tree_type, &size, NULL);
 -	if (!tree)
 -		return 0;
 -	init_tree_desc(&real, tree, size);
 -	init_tree_desc(&empty, "", 0);
 -
  	tree_difference = REV_TREE_SAME;
  	DIFF_OPT_CLR(&revs->pruning, HAS_CHANGES);
 -	retval = diff_tree(&empty, &real, "", &revs->pruning);
 -	free(tree);
 +	retval = diff_tree_sha1(NULL, t1->object.sha1, "", &revs->pruning);
  
  	return retval >= 0 && (tree_difference == REV_TREE_SAME);
  }
@@@ -1179,28 -1184,11 +1179,28 @@@ struct all_refs_cb 
  	const char *name_for_errormsg;
  };
  
 +int ref_excluded(struct string_list *ref_excludes, const char *path)
 +{
 +	struct string_list_item *item;
 +
 +	if (!ref_excludes)
 +		return 0;
 +	for_each_string_list_item(item, ref_excludes) {
 +		if (!wildmatch(item->string, path, 0, NULL))
 +			return 1;
 +	}
 +	return 0;
 +}
 +
  static int handle_one_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  {
  	struct all_refs_cb *cb = cb_data;
 -	struct object *object = get_reference(cb->all_revs, path, sha1,
 -					      cb->all_flags);
 +	struct object *object;
 +
 +	if (ref_excluded(cb->all_revs->ref_excludes, path))
 +	    return 0;
 +
 +	object = get_reference(cb->all_revs, path, sha1, cb->all_flags);
  	add_rev_cmdline(cb->all_revs, object, path, REV_CMD_REF, cb->all_flags);
  	add_pending_sha1(cb->all_revs, path, sha1, cb->all_flags);
  	return 0;
@@@ -1213,24 -1201,6 +1213,24 @@@ static void init_all_refs_cb(struct all
  	cb->all_flags = flags;
  }
  
 +void clear_ref_exclusion(struct string_list **ref_excludes_p)
 +{
 +	if (*ref_excludes_p) {
 +		string_list_clear(*ref_excludes_p, 0);
 +		free(*ref_excludes_p);
 +	}
 +	*ref_excludes_p = NULL;
 +}
 +
 +void add_ref_exclusion(struct string_list **ref_excludes_p, const char *exclude)
 +{
 +	if (!*ref_excludes_p) {
 +		*ref_excludes_p = xcalloc(1, sizeof(**ref_excludes_p));
 +		(*ref_excludes_p)->strdup_strings = 1;
 +	}
 +	string_list_append(*ref_excludes_p, exclude);
 +}
 +
  static void handle_refs(const char *submodule, struct rev_info *revs, unsigned flags,
  		int (*for_each)(const char *, each_ref_fn, void *))
  {
@@@ -1395,7 -1365,7 +1395,7 @@@ static void prepare_show_merge(struct r
  		const struct cache_entry *ce = active_cache[i];
  		if (!ce_stage(ce))
  			continue;
 -		if (ce_path_match(ce, &revs->prune_data)) {
 +		if (ce_path_match(ce, &revs->prune_data, NULL)) {
  			prune_num++;
  			prune = xrealloc(prune, sizeof(*prune) * prune_num);
  			prune[prune_num-2] = ce->name;
@@@ -1406,8 -1376,7 +1406,8 @@@
  			i++;
  	}
  	free_pathspec(&revs->prune_data);
 -	parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC, 0, "", prune);
 +	parse_pathspec(&revs->prune_data, PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
 +		       PATHSPEC_PREFER_FULL | PATHSPEC_LITERAL_PATH, "", prune);
  	revs->limited = 1;
  }
  
@@@ -1454,40 -1423,26 +1454,40 @@@ int handle_revision_arg(const char *arg
  		}
  		if (!get_sha1_committish(this, from_sha1) &&
  		    !get_sha1_committish(next, sha1)) {
 -			struct commit *a, *b;
 -			struct commit_list *exclude;
 -
 -			a = lookup_commit_reference(from_sha1);
 -			b = lookup_commit_reference(sha1);
 -			if (!a || !b) {
 -				if (revs->ignore_missing)
 -					return 0;
 -				die(symmetric ?
 -				    "Invalid symmetric difference expression %s...%s" :
 -				    "Invalid revision range %s..%s",
 -				    arg, next);
 -			}
 +			struct object *a_obj, *b_obj;
  
  			if (!cant_be_filename) {
  				*dotdot = '.';
  				verify_non_filename(revs->prefix, arg);
  			}
  
 -			if (symmetric) {
 +			a_obj = parse_object(from_sha1);
 +			b_obj = parse_object(sha1);
 +			if (!a_obj || !b_obj) {
 +			missing:
 +				if (revs->ignore_missing)
 +					return 0;
 +				die(symmetric
 +				    ? "Invalid symmetric difference expression %s"
 +				    : "Invalid revision range %s", arg);
 +			}
 +
 +			if (!symmetric) {
 +				/* just A..B */
 +				a_flags = flags_exclude;
 +			} else {
 +				/* A...B -- find merge bases between the two */
 +				struct commit *a, *b;
 +				struct commit_list *exclude;
 +
 +				a = (a_obj->type == OBJ_COMMIT
 +				     ? (struct commit *)a_obj
 +				     : lookup_commit_reference(a_obj->sha1));
 +				b = (b_obj->type == OBJ_COMMIT
 +				     ? (struct commit *)b_obj
 +				     : lookup_commit_reference(b_obj->sha1));
 +				if (!a || !b)
 +					goto missing;
  				exclude = get_merge_bases(a, b, 1);
  				add_rev_cmdline_list(revs, exclude,
  						     REV_CMD_MERGE_BASE,
@@@ -1495,18 -1450,17 +1495,18 @@@
  				add_pending_commit_list(revs, exclude,
  							flags_exclude);
  				free_commit_list(exclude);
 +
  				a_flags = flags | SYMMETRIC_LEFT;
 -			} else
 -				a_flags = flags_exclude;
 -			a->object.flags |= a_flags;
 -			b->object.flags |= flags;
 -			add_rev_cmdline(revs, &a->object, this,
 +			}
 +
 +			a_obj->flags |= a_flags;
 +			b_obj->flags |= flags;
 +			add_rev_cmdline(revs, a_obj, this,
  					REV_CMD_LEFT, a_flags);
 -			add_rev_cmdline(revs, &b->object, next,
 +			add_rev_cmdline(revs, b_obj, next,
  					REV_CMD_RIGHT, flags);
 -			add_pending_object(revs, &a->object, this);
 -			add_pending_object(revs, &b->object, next);
 +			add_pending_object(revs, a_obj, this);
 +			add_pending_object(revs, b_obj, next);
  			return 0;
  		}
  		*dotdot = '.';
@@@ -1553,7 -1507,7 +1553,7 @@@ struct cmdline_pathspec 
  static void append_prune_data(struct cmdline_pathspec *prune, const char **av)
  {
  	while (*av) {
 -		ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
 +		ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
  		prune->path[prune->nr++] = *(av++);
  	}
  }
@@@ -1565,7 -1519,7 +1565,7 @@@ static void read_pathspec_from_stdin(st
  		int len = sb->len;
  		if (len && sb->buf[len - 1] == '\n')
  			sb->buf[--len] = '\0';
 -		ALLOC_GROW(prune->path, prune->nr+1, prune->alloc);
 +		ALLOC_GROW(prune->path, prune->nr + 1, prune->alloc);
  		prune->path[prune->nr++] = xstrdup(sb->buf);
  	}
  }
@@@ -1575,10 -1529,6 +1575,10 @@@ static void read_revisions_from_stdin(s
  {
  	struct strbuf sb;
  	int seen_dashdash = 0;
 +	int save_warning;
 +
 +	save_warning = warn_on_object_refname_ambiguity;
 +	warn_on_object_refname_ambiguity = 0;
  
  	strbuf_init(&sb, 1000);
  	while (strbuf_getwholeline(&sb, stdin, '\n') != EOF) {
@@@ -1600,9 -1550,7 +1600,9 @@@
  	}
  	if (seen_dashdash)
  		read_pathspec_from_stdin(revs, &sb, prune);
 +
  	strbuf_release(&sb);
 +	warn_on_object_refname_ambiguity = save_warning;
  }
  
  static void add_grep(struct rev_info *revs, const char *ptn, enum grep_pat_token what)
@@@ -1632,9 -1580,9 +1632,9 @@@ static int handle_revision_opt(struct r
  	    !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
  	    !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
  	    !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk") ||
 -	    !strcmp(arg, "--bisect") || !prefixcmp(arg, "--glob=") ||
 -	    !prefixcmp(arg, "--branches=") || !prefixcmp(arg, "--tags=") ||
 -	    !prefixcmp(arg, "--remotes=") || !prefixcmp(arg, "--no-walk="))
 +	    !strcmp(arg, "--bisect") || starts_with(arg, "--glob=") ||
 +	    starts_with(arg, "--branches=") || starts_with(arg, "--tags=") ||
 +	    starts_with(arg, "--remotes=") || starts_with(arg, "--no-walk="))
  	{
  		unkv[(*unkc)++] = arg;
  		return 1;
@@@ -1657,7 -1605,7 +1657,7 @@@
  		revs->max_count = atoi(argv[1]);
  		revs->no_walk = 0;
  		return 2;
 -	} else if (!prefixcmp(arg, "-n")) {
 +	} else if (starts_with(arg, "-n")) {
  		revs->max_count = atoi(arg + 2);
  		revs->no_walk = 0;
  	} else if ((argcount = parse_long_opt("max-age", argv, &optarg))) {
@@@ -1717,7 -1665,7 +1717,7 @@@
  	} else if (!strcmp(arg, "--author-date-order")) {
  		revs->sort_order = REV_SORT_BY_AUTHOR_DATE;
  		revs->topo_order = 1;
 -	} else if (!prefixcmp(arg, "--early-output")) {
 +	} else if (starts_with(arg, "--early-output")) {
  		int count = 100;
  		switch (arg[14]) {
  		case '=':
@@@ -1742,13 -1690,13 +1742,13 @@@
  		revs->min_parents = 2;
  	} else if (!strcmp(arg, "--no-merges")) {
  		revs->max_parents = 1;
 -	} else if (!prefixcmp(arg, "--min-parents=")) {
 +	} else if (starts_with(arg, "--min-parents=")) {
  		revs->min_parents = atoi(arg+14);
 -	} else if (!prefixcmp(arg, "--no-min-parents")) {
 +	} else if (starts_with(arg, "--no-min-parents")) {
  		revs->min_parents = 0;
 -	} else if (!prefixcmp(arg, "--max-parents=")) {
 +	} else if (starts_with(arg, "--max-parents=")) {
  		revs->max_parents = atoi(arg+14);
 -	} else if (!prefixcmp(arg, "--no-max-parents")) {
 +	} else if (starts_with(arg, "--no-max-parents")) {
  		revs->max_parents = -1;
  	} else if (!strcmp(arg, "--boundary")) {
  		revs->boundary = 1;
@@@ -1798,7 -1746,7 +1798,7 @@@
  		revs->verify_objects = 1;
  	} else if (!strcmp(arg, "--unpacked")) {
  		revs->unpacked = 1;
 -	} else if (!prefixcmp(arg, "--unpacked=")) {
 +	} else if (starts_with(arg, "--unpacked=")) {
  		die("--unpacked=<packfile> no longer supported.");
  	} else if (!strcmp(arg, "-r")) {
  		revs->diff = 1;
@@@ -1823,7 -1771,7 +1823,7 @@@
  		revs->verbose_header = 1;
  		revs->pretty_given = 1;
  		get_commit_format(arg+8, revs);
 -	} else if (!prefixcmp(arg, "--pretty=") || !prefixcmp(arg, "--format=")) {
 +	} else if (starts_with(arg, "--pretty=") || starts_with(arg, "--format=")) {
  		/*
  		 * Detached form ("--pretty X" as opposed to "--pretty=X")
  		 * not allowed, since the argument is optional.
@@@ -1837,20 -1785,12 +1837,20 @@@
  		revs->notes_opt.use_default_notes = 1;
  	} else if (!strcmp(arg, "--show-signature")) {
  		revs->show_signature = 1;
 -	} else if (!prefixcmp(arg, "--show-notes=") ||
 -		   !prefixcmp(arg, "--notes=")) {
 +	} else if (!strcmp(arg, "--show-linear-break") ||
 +		   starts_with(arg, "--show-linear-break=")) {
 +		if (starts_with(arg, "--show-linear-break="))
 +			revs->break_bar = xstrdup(arg + 20);
 +		else
 +			revs->break_bar = "                    ..........";
 +		revs->track_linear = 1;
 +		revs->track_first_time = 1;
 +	} else if (starts_with(arg, "--show-notes=") ||
 +		   starts_with(arg, "--notes=")) {
  		struct strbuf buf = STRBUF_INIT;
  		revs->show_notes = 1;
  		revs->show_notes_given = 1;
 -		if (!prefixcmp(arg, "--show-notes")) {
 +		if (starts_with(arg, "--show-notes")) {
  			if (revs->notes_opt.use_default_notes < 0)
  				revs->notes_opt.use_default_notes = 1;
  			strbuf_addstr(&buf, arg+13);
@@@ -1893,7 -1833,7 +1893,7 @@@
  		revs->abbrev = 0;
  	} else if (!strcmp(arg, "--abbrev")) {
  		revs->abbrev = DEFAULT_ABBREV;
 -	} else if (!prefixcmp(arg, "--abbrev=")) {
 +	} else if (starts_with(arg, "--abbrev=")) {
  		revs->abbrev = strtoul(arg + 9, NULL, 10);
  		if (revs->abbrev < MINIMUM_ABBREV)
  			revs->abbrev = MINIMUM_ABBREV;
@@@ -1968,8 -1908,6 +1968,8 @@@
  			unkv[(*unkc)++] = arg;
  		return opts;
  	}
 +	if (revs->graph && revs->track_linear)
 +		die("--show-linear-break and --graph are incompatible");
  
  	return 1;
  }
@@@ -2019,51 -1957,40 +2019,51 @@@ static int handle_revision_pseudo_opt(c
  	if (!strcmp(arg, "--all")) {
  		handle_refs(submodule, revs, *flags, for_each_ref_submodule);
  		handle_refs(submodule, revs, *flags, head_ref_submodule);
 +		clear_ref_exclusion(&revs->ref_excludes);
  	} else if (!strcmp(arg, "--branches")) {
  		handle_refs(submodule, revs, *flags, for_each_branch_ref_submodule);
 +		clear_ref_exclusion(&revs->ref_excludes);
  	} else if (!strcmp(arg, "--bisect")) {
  		handle_refs(submodule, revs, *flags, for_each_bad_bisect_ref);
  		handle_refs(submodule, revs, *flags ^ (UNINTERESTING | BOTTOM), for_each_good_bisect_ref);
  		revs->bisect = 1;
  	} else if (!strcmp(arg, "--tags")) {
  		handle_refs(submodule, revs, *flags, for_each_tag_ref_submodule);
 +		clear_ref_exclusion(&revs->ref_excludes);
  	} else if (!strcmp(arg, "--remotes")) {
  		handle_refs(submodule, revs, *flags, for_each_remote_ref_submodule);
 +		clear_ref_exclusion(&revs->ref_excludes);
  	} else if ((argcount = parse_long_opt("glob", argv, &optarg))) {
  		struct all_refs_cb cb;
  		init_all_refs_cb(&cb, revs, *flags);
  		for_each_glob_ref(handle_one_ref, optarg, &cb);
 +		clear_ref_exclusion(&revs->ref_excludes);
 +		return argcount;
 +	} else if ((argcount = parse_long_opt("exclude", argv, &optarg))) {
 +		add_ref_exclusion(&revs->ref_excludes, optarg);
  		return argcount;
 -	} else if (!prefixcmp(arg, "--branches=")) {
 +	} else if (starts_with(arg, "--branches=")) {
  		struct all_refs_cb cb;
  		init_all_refs_cb(&cb, revs, *flags);
  		for_each_glob_ref_in(handle_one_ref, arg + 11, "refs/heads/", &cb);
 -	} else if (!prefixcmp(arg, "--tags=")) {
 +		clear_ref_exclusion(&revs->ref_excludes);
 +	} else if (starts_with(arg, "--tags=")) {
  		struct all_refs_cb cb;
  		init_all_refs_cb(&cb, revs, *flags);
  		for_each_glob_ref_in(handle_one_ref, arg + 7, "refs/tags/", &cb);
 -	} else if (!prefixcmp(arg, "--remotes=")) {
 +		clear_ref_exclusion(&revs->ref_excludes);
 +	} else if (starts_with(arg, "--remotes=")) {
  		struct all_refs_cb cb;
  		init_all_refs_cb(&cb, revs, *flags);
  		for_each_glob_ref_in(handle_one_ref, arg + 10, "refs/remotes/", &cb);
 +		clear_ref_exclusion(&revs->ref_excludes);
  	} else if (!strcmp(arg, "--reflog")) {
  		handle_reflog(revs, *flags);
  	} else if (!strcmp(arg, "--not")) {
  		*flags ^= UNINTERESTING | BOTTOM;
  	} else if (!strcmp(arg, "--no-walk")) {
  		revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
 -	} else if (!prefixcmp(arg, "--no-walk=")) {
 +	} else if (starts_with(arg, "--no-walk=")) {
  		/*
  		 * Detached form ("--no-walk X" as opposed to "--no-walk=X")
  		 * not allowed, since the argument is optional.
@@@ -2195,7 -2122,7 +2195,7 @@@ int setup_revisions(int argc, const cha
  		 *	call init_pathspec() to set revs->prune_data here.
  		 * }
  		 */
 -		ALLOC_GROW(prune_data.path, prune_data.nr+1, prune_data.alloc);
 +		ALLOC_GROW(prune_data.path, prune_data.nr + 1, prune_data.alloc);
  		prune_data.path[prune_data.nr++] = NULL;
  		parse_pathspec(&revs->prune_data, 0, 0,
  			       revs->prefix, prune_data.path);
@@@ -2912,27 -2839,6 +2912,27 @@@ enum commit_action simplify_commit(stru
  	return action;
  }
  
 +static void track_linear(struct rev_info *revs, struct commit *commit)
 +{
 +	if (revs->track_first_time) {
 +		revs->linear = 1;
 +		revs->track_first_time = 0;
 +	} else {
 +		struct commit_list *p;
 +		for (p = revs->previous_parents; p; p = p->next)
 +			if (p->item == NULL || /* first commit */
 +			    !hashcmp(p->item->object.sha1, commit->object.sha1))
 +				break;
 +		revs->linear = p != NULL;
 +	}
 +	if (revs->reverse) {
 +		if (revs->linear)
 +			commit->object.flags |= TRACK_LINEAR;
 +	}
 +	free_commit_list(revs->previous_parents);
 +	revs->previous_parents = copy_commit_list(commit->parents);
 +}
 +
  static struct commit *get_revision_1(struct rev_info *revs)
  {
  	if (!revs->commits)
@@@ -2960,9 -2866,11 +2960,11 @@@
  			if (revs->max_age != -1 &&
  			    (commit->date < revs->max_age))
  				continue;
- 			if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0)
- 				die("Failed to traverse parents of commit %s",
- 				    sha1_to_hex(commit->object.sha1));
+ 			if (add_parents_to_list(revs, commit, &revs->commits, NULL) < 0) {
+ 				if (!revs->ignore_missing_links)
+ 					die("Failed to traverse parents of commit %s",
+ 						sha1_to_hex(commit->object.sha1));
+ 			}
  		}
  
  		switch (simplify_commit(revs, commit)) {
@@@ -2972,8 -2880,6 +2974,8 @@@
  			die("Failed to simplify parents of commit %s",
  			    sha1_to_hex(commit->object.sha1));
  		default:
 +			if (revs->track_linear)
 +				track_linear(revs, commit);
  			return commit;
  		}
  	} while (revs->commits);
@@@ -3071,7 -2977,7 +3073,7 @@@ static struct commit *get_revision_inte
  	if (revs->max_count) {
  		c = get_revision_1(revs);
  		if (c) {
 -			while (0 < revs->skip_count) {
 +			while (revs->skip_count > 0) {
  				revs->skip_count--;
  				c = get_revision_1(revs);
  				if (!c)
@@@ -3086,8 -2992,9 +3088,8 @@@
  	if (c)
  		c->object.flags |= SHOWN;
  
 -	if (!revs->boundary) {
 +	if (!revs->boundary)
  		return c;
 -	}
  
  	if (!c) {
  		/*
@@@ -3133,30 -3040,22 +3135,30 @@@ struct commit *get_revision(struct rev_
  
  	if (revs->reverse) {
  		reversed = NULL;
 -		while ((c = get_revision_internal(revs))) {
 +		while ((c = get_revision_internal(revs)))
  			commit_list_insert(c, &reversed);
 -		}
  		revs->commits = reversed;
  		revs->reverse = 0;
  		revs->reverse_output_stage = 1;
  	}
  
 -	if (revs->reverse_output_stage)
 -		return pop_commit(&revs->commits);
 +	if (revs->reverse_output_stage) {
 +		c = pop_commit(&revs->commits);
 +		if (revs->track_linear)
 +			revs->linear = !!(c && c->object.flags & TRACK_LINEAR);
 +		return c;
 +	}
  
  	c = get_revision_internal(revs);
  	if (c && revs->graph)
  		graph_update(revs->graph, c);
 -	if (!c)
 +	if (!c) {
  		free_saved_parents(revs);
 +		if (revs->previous_parents) {
 +			free_commit_list(revs->previous_parents);
 +			revs->previous_parents = NULL;
 +		}
 +	}
  	return c;
  }
  
diff --combined revision.h
index d9907dd460,4f051d2ea2..a6205307cf
--- a/revision.h
+++ b/revision.h
@@@ -5,9 -5,7 +5,9 @@@
  #include "grep.h"
  #include "notes.h"
  #include "commit.h"
 +#include "diff.h"
  
 +/* Remember to update object flag allocation in object.h */
  #define SEEN		(1u<<0)
  #define UNINTERESTING   (1u<<1)
  #define TREESAME	(1u<<2)
@@@ -19,8 -17,7 +19,8 @@@
  #define SYMMETRIC_LEFT	(1u<<8)
  #define PATCHSAME	(1u<<9)
  #define BOTTOM		(1u<<10)
 -#define ALL_REV_FLAGS	((1u<<11)-1)
 +#define TRACK_LINEAR	(1u<<26)
 +#define ALL_REV_FLAGS	(((1u<<11)-1) | TRACK_LINEAR)
  
  #define DECORATE_SHORT_REFS	1
  #define DECORATE_FULL_REFS	2
@@@ -63,9 -60,6 +63,9 @@@ struct rev_info 
  	/* The end-points specified by the end user */
  	struct rev_cmdline_info cmdline;
  
 +	/* excluding from --branches, --refs, etc. expansion */
 +	struct string_list *ref_excludes;
 +
  	/* Basic information */
  	const char *prefix;
  	const char *def;
@@@ -75,7 -69,8 +75,8 @@@
  	enum rev_sort_order sort_order;
  
  	unsigned int	early_output:1,
- 			ignore_missing:1;
+ 			ignore_missing:1,
+ 			ignore_missing_links:1;
  
  	/* Traversal flags */
  	unsigned int	dense:1,
@@@ -139,10 -134,6 +140,10 @@@
  			preserve_subject:1;
  	unsigned int	disable_stdin:1;
  	unsigned int	leak_pending:1;
 +	/* --show-linear-break */
 +	unsigned int	track_linear:1,
 +			track_first_time:1,
 +			linear:1;
  
  	enum date_mode date_mode;
  
@@@ -203,16 -194,8 +204,16 @@@
  
  	/* copies of the parent lists, for --full-diff display */
  	struct saved_parents *saved_parents_slab;
 +
 +	struct commit_list *previous_parents;
 +	const char *break_bar;
  };
  
 +extern int ref_excluded(struct string_list *, const char *path);
 +void clear_ref_exclusion(struct string_list **);
 +void add_ref_exclusion(struct string_list **, const char *exclude);
 +
 +
  #define REV_TREE_SAME		0
  #define REV_TREE_NEW		1	/* Only new files */
  #define REV_TREE_OLD		2	/* Only files removed */