Merge branch 'ph/parseopt-step-blame'

* ph/parseopt-step-blame:
  revisions: refactor handle_revision_opt into parse_revision_opt.
  git-shortlog: migrate to parse-options partially.
  git-blame: fix lapsus
  git-blame: migrate to incremental parse-option [2/2]
  git-blame: migrate to incremental parse-option [1/2]
  revisions: split handle_revision_opt() from setup_revisions()
  parse-opt: add PARSE_OPT_KEEP_ARGV0 parser option.
  parse-opt: fake short strings for callers to believe in.
  parse-opt: do not print errors on unknown options, return -2 intead.
  parse-opt: create parse_options_step.
  parse-opt: Export a non NORETURN usage dumper.
  parse-opt: have parse_options_{start,end}.
  git-blame --reverse
  builtin-blame.c: allow more than 16 parents
  builtin-blame.c: move prepare_final() into a separate function.
  rev-list --children
  revision traversal: --children option

8 files changed, 788 insertions, 673 deletions

diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index 37dd1d61ea..b6f5d87e72 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@ -45,6 +45,10 @@ endif::git-rev-list[]
 
 	Print the parents of the commit.
 
+--children::
+
+	Print the children of the commit.
+
 ifdef::git-rev-list[]
 --timestamp::
 	Print the raw commit timestamp.
diff --git a/builtin-blame.c b/builtin-blame.c
index b451f6c64d..06c7de4297 100644
--- a/builtin-blame.c
+++ b/builtin-blame.c
@@ -18,24 +18,16 @@
 #include "cache-tree.h"
 #include "path-list.h"
 #include "mailmap.h"
+#include "parse-options.h"
 
-static char blame_usage[] =
-"git-blame [-c] [-b] [-l] [--root] [-t] [-f] [-n] [-s] [-p] [-w] [-L n,m] [-S <revs-file>] [-M] [-C] [-C] [--contents <filename>] [--incremental] [commit] [--] file\n"
-"  -c                  Use the same output mode as git-annotate (Default: off)\n"
-"  -b                  Show blank SHA-1 for boundary commits (Default: off)\n"
-"  -l                  Show long commit SHA1 (Default: off)\n"
-"  --root              Do not treat root commits as boundaries (Default: off)\n"
-"  -t                  Show raw timestamp (Default: off)\n"
-"  -f, --show-name     Show original filename (Default: auto)\n"
-"  -n, --show-number   Show original linenumber (Default: off)\n"
-"  -s                  Suppress author name and timestamp (Default: off)\n"
-"  -p, --porcelain     Show in a format designed for machine consumption\n"
-"  -w                  Ignore whitespace differences\n"
-"  -L n,m              Process only line range n,m, counting from 1\n"
-"  -M, -C              Find line movements within and across files\n"
-"  --incremental       Show blame entries as we find them, incrementally\n"
-"  --contents file     Use <file>'s contents as the final image\n"
-"  -S revs-file        Use revisions from revs-file instead of calling git-rev-list\n";
+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;
@@ -43,6 +35,7 @@ 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 cmd_is_annotate;
@@ -91,7 +84,7 @@ struct origin {
  * Given an origin, prepare mmfile_t structure to be used by the
  * diff machinery
  */
-static char *fill_origin_blob(struct origin *o, mmfile_t *file)
+static void fill_origin_blob(struct origin *o, mmfile_t *file)
 {
 	if (!o->file.ptr) {
 		enum object_type type;
@@ -106,7 +99,6 @@ static char *fill_origin_blob(struct origin *o, mmfile_t *file)
 	}
 	else
 		*file = o->file;
-	return file->ptr;
 }
 
 /*
@@ -178,7 +170,7 @@ struct blame_entry {
 struct scoreboard {
 	/* the final commit (i.e. where we started digging from) */
 	struct commit *final;
-
+	struct rev_info *revs;
 	const char *path;
 
 	/*
@@ -1192,18 +1184,48 @@ static void pass_whole_blame(struct scoreboard *sb,
 	}
 }
 
-#define MAXPARENT 16
+/*
+ * 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)
 {
-	int i, pass;
+	struct rev_info *revs = sb->revs;
+	int i, pass, num_sg;
 	struct commit *commit = origin->commit;
-	struct commit_list *parent;
-	struct origin *parent_origin[MAXPARENT], *porigin;
-
-	memset(parent_origin, 0, sizeof(parent_origin));
+	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
+	/*
+	 * 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++) {
@@ -1211,13 +1233,13 @@ static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
 				       struct commit *, struct origin *);
 		find = pass ? find_rename : find_origin;
 
-		for (i = 0, parent = commit->parents;
-		     i < MAXPARENT && parent;
-		     parent = parent->next, i++) {
-			struct commit *p = parent->item;
+		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 (parent_origin[i])
+			if (sg_origin[i])
 				continue;
 			if (parse_commit(p))
 				continue;
@@ -1230,24 +1252,24 @@ static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
 				goto finish;
 			}
 			for (j = same = 0; j < i; j++)
-				if (parent_origin[j] &&
-				    !hashcmp(parent_origin[j]->blob_sha1,
+				if (sg_origin[j] &&
+				    !hashcmp(sg_origin[j]->blob_sha1,
 					     porigin->blob_sha1)) {
 					same = 1;
 					break;
 				}
 			if (!same)
-				parent_origin[i] = porigin;
+				sg_origin[i] = porigin;
 			else
 				origin_decref(porigin);
 		}
 	}
 
 	num_commits++;
-	for (i = 0, parent = commit->parents;
-	     i < MAXPARENT && parent;
-	     parent = parent->next, i++) {
-		struct origin *porigin = parent_origin[i];
+	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 (pass_blame_to_parent(sb, origin, porigin))
@@ -1258,10 +1280,10 @@ static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
 	 * Optionally find moves in parents' files.
 	 */
 	if (opt & PICKAXE_BLAME_MOVE)
-		for (i = 0, parent = commit->parents;
-		     i < MAXPARENT && parent;
-		     parent = parent->next, i++) {
-			struct origin *porigin = parent_origin[i];
+		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))
@@ -1272,23 +1294,25 @@ static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
 	 * Optionally find copies from parents' files.
 	 */
 	if (opt & PICKAXE_BLAME_COPY)
-		for (i = 0, parent = commit->parents;
-		     i < MAXPARENT && parent;
-		     parent = parent->next, i++) {
-			struct origin *porigin = parent_origin[i];
-			if (find_copy_in_parent(sb, origin, parent->item,
+		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 < MAXPARENT; i++) {
-		if (parent_origin[i]) {
-			drop_origin_blob(parent_origin[i]);
-			origin_decref(parent_origin[i]);
+	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);
 }
 
 /*
@@ -1487,8 +1511,10 @@ static void found_guilty_entry(struct blame_entry *ent)
  * 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, struct rev_info *revs, int opt)
+static void assign_blame(struct scoreboard *sb, int opt)
 {
+	struct rev_info *revs = sb->revs;
+
 	while (1) {
 		struct blame_entry *ent;
 		struct commit *commit;
@@ -1509,8 +1535,9 @@ static void assign_blame(struct scoreboard *sb, struct rev_info *revs, int opt)
 		commit = suspect->commit;
 		if (!commit->object.parsed)
 			parse_commit(commit);
-		if (!(commit->object.flags & UNINTERESTING) &&
-		    !(revs->max_age != -1 && commit->date < revs->max_age))
+		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;
@@ -2006,6 +2033,10 @@ static int git_blame_config(const char *var, const char *value, void *cb)
 	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;
@@ -2122,6 +2153,108 @@ static struct commit *fake_working_tree_commit(const char *path, const char *con
 	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;
@@ -2129,102 +2262,66 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 	struct scoreboard sb;
 	struct origin *o;
 	struct blame_entry *ent;
-	int i, seen_dashdash, unk, opt;
-	long bottom, top, lno;
-	int output_option = 0;
-	int show_stats = 0;
-	const char *revs_file = NULL;
+	long dashdash_pos, bottom, top, lno;
 	const char *final_commit_name = NULL;
 	enum object_type type;
-	const char *bottomtop = NULL;
-	const char *contents_from = NULL;
+
+	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;
 
 	cmd_is_annotate = !strcmp(argv[0], "annotate");
 
 	git_config(git_blame_config, NULL);
+	init_revisions(&revs, NULL);
 	save_commit_buffer = 0;
-
-	opt = 0;
-	seen_dashdash = 0;
-	for (unk = i = 1; i < argc; i++) {
-		const char *arg = argv[i];
-		if (*arg != '-')
-			break;
-		else if (!strcmp("-b", arg))
-			blank_boundary = 1;
-		else if (!strcmp("--root", arg))
-			show_root = 1;
-		else if (!strcmp(arg, "--show-stats"))
-			show_stats = 1;
-		else if (!strcmp("-c", arg))
-			output_option |= OUTPUT_ANNOTATE_COMPAT;
-		else if (!strcmp("-t", arg))
-			output_option |= OUTPUT_RAW_TIMESTAMP;
-		else if (!strcmp("-l", arg))
-			output_option |= OUTPUT_LONG_OBJECT_NAME;
-		else if (!strcmp("-s", arg))
-			output_option |= OUTPUT_NO_AUTHOR;
-		else if (!strcmp("-w", arg))
-			xdl_opts |= XDF_IGNORE_WHITESPACE;
-		else if (!strcmp("-S", arg) && ++i < argc)
-			revs_file = argv[i];
-		else if (!prefixcmp(arg, "-M")) {
-			opt |= PICKAXE_BLAME_MOVE;
-			blame_move_score = parse_score(arg+2);
-		}
-		else if (!prefixcmp(arg, "-C")) {
-			/*
-			 * -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;
-			blame_copy_score = parse_score(arg+2);
-		}
-		else if (!prefixcmp(arg, "-L")) {
-			if (!arg[2]) {
-				if (++i >= argc)
-					usage(blame_usage);
-				arg = argv[i];
-			}
-			else
-				arg += 2;
-			if (bottomtop)
-				die("More than one '-L n,m' option given");
-			bottomtop = arg;
+	dashdash_pos = 0;
+
+	parse_options_start(&ctx, argc, argv, 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;
 		}
-		else if (!strcmp("--contents", arg)) {
-			if (++i >= argc)
-				usage(blame_usage);
-			contents_from = argv[i];
-		}
-		else if (!strcmp("--incremental", arg))
-			incremental = 1;
-		else if (!strcmp("--score-debug", arg))
-			output_option |= OUTPUT_SHOW_SCORE;
-		else if (!strcmp("-f", arg) ||
-			 !strcmp("--show-name", arg))
-			output_option |= OUTPUT_SHOW_NAME;
-		else if (!strcmp("-n", arg) ||
-			 !strcmp("--show-number", arg))
-			output_option |= OUTPUT_SHOW_NUMBER;
-		else if (!strcmp("-p", arg) ||
-			 !strcmp("--porcelain", arg))
-			output_option |= OUTPUT_PORCELAIN;
-		else if (!strcmp("--", arg)) {
-			seen_dashdash = 1;
-			i++;
-			break;
+
+		if (!strcmp(ctx.argv[0], "--reverse")) {
+			ctx.argv[0] = "--children";
+			reverse = 1;
 		}
-		else
-			argv[unk++] = arg;
+		parse_revision_opt(&revs, &ctx, options, blame_opt_usage);
 	}
+parse_done:
+	argc = parse_options_end(&ctx);
 
 	if (!blame_move_score)
 		blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
@@ -2238,115 +2335,59 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 	 *
 	 * The remaining are:
 	 *
-	 * (1) if seen_dashdash, its either
-	 *     "-options -- <path>" or
-	 *     "-options -- <path> <rev>".
-	 *     but the latter is allowed only if there is no
-	 *     options that we passed to revision machinery.
+	 * (1) if dashdash_pos != 0, its either
+	 *     "blame [revisions] -- <path>" or
+	 *     "blame -- <path> <rev>"
 	 *
-	 * (2) otherwise, we may have "--" somewhere later and
-	 *     might be looking at the first one of multiple 'rev'
-	 *     parameters (e.g. " master ^next ^maint -- path").
-	 *     See if there is a dashdash first, and give the
-	 *     arguments before that to revision machinery.
-	 *     After that there must be one 'path'.
+	 * (2) otherwise, its one of the two:
+	 *     "blame [revisions] <path>"
+	 *     "blame <path> <rev>"
 	 *
-	 * (3) otherwise, its one of the three:
-	 *     "-options <path> <rev>"
-	 *     "-options <rev> <path>"
-	 *     "-options <path>"
-	 *     but again the first one is allowed only if
-	 *     there is no options that we passed to revision
-	 *     machinery.
+	 * Note that we must strip out <path> from the arguments: we do not
+	 * want the path pruning but we may want "bottom" processing.
 	 */
-
-	if (seen_dashdash) {
-		/* (1) */
-		if (argc <= i)
-			usage(blame_usage);
-		path = add_prefix(prefix, argv[i]);
-		if (i + 1 == argc - 1) {
-			if (unk != 1)
-				usage(blame_usage);
-			argv[unk++] = argv[i + 1];
+	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 (i + 1 != argc)
-			/* garbage at end */
-			usage(blame_usage);
-	}
-	else {
-		int j;
-		for (j = i; !seen_dashdash && j < argc; j++)
-			if (!strcmp(argv[j], "--"))
-				seen_dashdash = j;
-		if (seen_dashdash) {
-			/* (2) */
-			if (seen_dashdash + 1 != argc - 1)
-				usage(blame_usage);
-			path = add_prefix(prefix, argv[seen_dashdash + 1]);
-			for (j = i; j < seen_dashdash; j++)
-				argv[unk++] = argv[j];
+	} else {
+		if (argc < 2)
+			usage_with_options(blame_opt_usage, options);
+		path = add_prefix(prefix, argv[argc - 1]);
+		if (argc == 3 && !has_path_in_work_tree(path)) { /* (2b) */
+			path = add_prefix(prefix, argv[1]);
+			argv[1] = argv[2];
 		}
-		else {
-			/* (3) */
-			if (argc <= i)
-				usage(blame_usage);
-			path = add_prefix(prefix, argv[i]);
-			if (i + 1 == argc - 1) {
-				final_commit_name = argv[i + 1];
-
-				/* if (unk == 1) we could be getting
-				 * old-style
-				 */
-				if (unk == 1 && !has_path_in_work_tree(path)) {
-					path = add_prefix(prefix, argv[i + 1]);
-					final_commit_name = argv[i];
-				}
-			}
-			else if (i != argc - 1)
-				usage(blame_usage); /* garbage at end */
+		argv[argc - 1] = "--";
 
-			setup_work_tree();
-			if (!has_path_in_work_tree(path))
-				die("cannot stat path %s: %s",
-				    path, strerror(errno));
-		}
+		setup_work_tree();
+		if (!has_path_in_work_tree(path))
+			die("cannot stat path %s: %s", path, strerror(errno));
 	}
 
-	if (final_commit_name)
-		argv[unk++] = final_commit_name;
-
-	/*
-	 * Now we got rev and path.  We do not want the path pruning
-	 * but we may want "bottom" processing.
-	 */
-	argv[unk++] = "--"; /* terminate the rev name */
-	argv[unk] = NULL;
-
-	init_revisions(&revs, NULL);
-	setup_revisions(unk, argv, &revs, NULL);
+	setup_revisions(argc, argv, &revs, NULL);
 	memset(&sb, 0, sizeof(sb));
 
-	/*
-	 * 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;
-	}
+	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) {
 		/*
@@ -2425,7 +2466,7 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 	if (!incremental)
 		setup_pager();
 
-	assign_blame(&sb, &revs, opt);
+	assign_blame(&sb, opt);
 
 	if (incremental)
 		return 0;
diff --git a/builtin-rev-list.c b/builtin-rev-list.c
index 54b6672969..b4a2c447f2 100644
--- a/builtin-rev-list.c
+++ b/builtin-rev-list.c
@@ -37,6 +37,7 @@ static const char rev_list_usage[] =
 "    --reverse\n"
 "  formatting output:\n"
 "    --parents\n"
+"    --children\n"
 "    --objects | --objects-edge\n"
 "    --unpacked\n"
 "    --header | --pretty\n"
@@ -90,6 +91,15 @@ static void show_commit(struct commit *commit)
 			parents = parents->next;
 		}
 	}
+	if (revs.children.name) {
+		struct commit_list *children;
+
+		children = lookup_decoration(&revs.children, &commit->object);
+		while (children) {
+			printf(" %s", sha1_to_hex(children->item->object.sha1));
+			children = children->next;
+		}
+	}
 	show_decorations(commit);
 	if (revs.commit_format == CMIT_FMT_ONELINE)
 		putchar(' ');
diff --git a/builtin-shortlog.c b/builtin-shortlog.c
index e6a2865019..01362022c0 100644
--- a/builtin-shortlog.c
+++ b/builtin-shortlog.c
@@ -7,9 +7,14 @@
 #include "utf8.h"
 #include "mailmap.h"
 #include "shortlog.h"
+#include "parse-options.h"
 
-static const char shortlog_usage[] =
-"git-shortlog [-n] [-s] [-e] [-w] [<commit-id>... ]";
+static char const * const shortlog_usage[] = {
+	"git-shortlog [-n] [-s] [-e] [-w] [rev-opts] [--] [<commit-id>... ]",
+	"",
+	"[rev-opts] are documented in git-rev-list(1)",
+	NULL
+};
 
 static int compare_by_number(const void *a1, const void *a2)
 {
@@ -164,21 +169,19 @@ static void get_from_rev(struct rev_info *rev, struct shortlog *log)
 		shortlog_add_commit(log, commit);
 }
 
-static int parse_uint(char const **arg, int comma)
+static int parse_uint(char const **arg, int comma, int defval)
 {
 	unsigned long ul;
 	int ret;
 	char *endp;
 
 	ul = strtoul(*arg, &endp, 10);
-	if (endp != *arg && *endp && *endp != comma)
+	if (*endp && *endp != comma)
 		return -1;
-	ret = (int) ul;
-	if (ret != ul)
+	if (ul > INT_MAX)
 		return -1;
-	*arg = endp;
-	if (**arg)
-		(*arg)++;
+	ret = *arg == endp ? defval : (int)ul;
+	*arg = *endp ? endp + 1 : endp;
 	return ret;
 }
 
@@ -187,30 +190,30 @@ static const char wrap_arg_usage[] = "-w[<width>[,<indent1>[,<indent2>]]]";
 #define DEFAULT_INDENT1 6
 #define DEFAULT_INDENT2 9
 
-static void parse_wrap_args(const char *arg, int *in1, int *in2, int *wrap)
+static int parse_wrap_args(const struct option *opt, const char *arg, int unset)
 {
-	arg += 2; /* skip -w */
-
-	*wrap = parse_uint(&arg, ',');
-	if (*wrap < 0)
-		die(wrap_arg_usage);
-	*in1 = parse_uint(&arg, ',');
-	if (*in1 < 0)
-		die(wrap_arg_usage);
-	*in2 = parse_uint(&arg, '\0');
-	if (*in2 < 0)
-		die(wrap_arg_usage);
-
-	if (!*wrap)
-		*wrap = DEFAULT_WRAPLEN;
-	if (!*in1)
-		*in1 = DEFAULT_INDENT1;
-	if (!*in2)
-		*in2 = DEFAULT_INDENT2;
-	if (*wrap &&
-	    ((*in1 && *wrap <= *in1) ||
-	     (*in2 && *wrap <= *in2)))
-		die(wrap_arg_usage);
+	struct shortlog *log = opt->value;
+
+	log->wrap_lines = !unset;
+	if (unset)
+		return 0;
+	if (!arg) {
+		log->wrap = DEFAULT_WRAPLEN;
+		log->in1 = DEFAULT_INDENT1;
+		log->in2 = DEFAULT_INDENT2;
+		return 0;
+	}
+
+	log->wrap = parse_uint(&arg, ',', DEFAULT_WRAPLEN);
+	log->in1 = parse_uint(&arg, ',', DEFAULT_INDENT1);
+	log->in2 = parse_uint(&arg, '\0', DEFAULT_INDENT2);
+	if (log->wrap < 0 || log->in1 < 0 || log->in2 < 0)
+		return error(wrap_arg_usage);
+	if (log->wrap &&
+	    ((log->in1 && log->wrap <= log->in1) ||
+	     (log->in2 && log->wrap <= log->in2)))
+		return error(wrap_arg_usage);
+	return 0;
 }
 
 void shortlog_init(struct shortlog *log)
@@ -227,38 +230,46 @@ void shortlog_init(struct shortlog *log)
 
 int cmd_shortlog(int argc, const char **argv, const char *prefix)
 {
-	struct shortlog log;
-	struct rev_info rev;
+	static struct shortlog log;
+	static struct rev_info rev;
 	int nongit;
 
+	static const struct option options[] = {
+		OPT_BOOLEAN('n', "numbered", &log.sort_by_number,
+			    "sort output according to the number of commits per author"),
+		OPT_BOOLEAN('s', "summary", &log.summary,
+			    "Suppress commit descriptions, only provides commit count"),
+		OPT_BOOLEAN('e', "email", &log.email,
+			    "Show the email address of each author"),
+		{ OPTION_CALLBACK, 'w', NULL, &log, "w[,i1[,i2]]",
+			"Linewrap output", PARSE_OPT_OPTARG, &parse_wrap_args },
+		OPT_END(),
+	};
+
+	struct parse_opt_ctx_t ctx;
+
 	prefix = setup_git_directory_gently(&nongit);
 	shortlog_init(&log);
-
-	/* since -n is a shadowed rev argument, parse our args first */
-	while (argc > 1) {
-		if (!strcmp(argv[1], "-n") || !strcmp(argv[1], "--numbered"))
-			log.sort_by_number = 1;
-		else if (!strcmp(argv[1], "-s") ||
-				!strcmp(argv[1], "--summary"))
-			log.summary = 1;
-		else if (!strcmp(argv[1], "-e") ||
-			 !strcmp(argv[1], "--email"))
-			log.email = 1;
-		else if (!prefixcmp(argv[1], "-w")) {
-			log.wrap_lines = 1;
-			parse_wrap_args(argv[1], &log.in1, &log.in2, &log.wrap);
+	init_revisions(&rev, prefix);
+	parse_options_start(&ctx, argc, argv, PARSE_OPT_KEEP_DASHDASH |
+			    PARSE_OPT_KEEP_ARGV0);
+
+	for (;;) {
+		switch (parse_options_step(&ctx, options, shortlog_usage)) {
+		case PARSE_OPT_HELP:
+			exit(129);
+		case PARSE_OPT_DONE:
+			goto parse_done;
 		}
-		else if (!strcmp(argv[1], "-h") || !strcmp(argv[1], "--help"))
-			usage(shortlog_usage);
-		else
-			break;
-		argv++;
-		argc--;
+		parse_revision_opt(&rev, &ctx, options, shortlog_usage);
+	}
+parse_done:
+	argc = parse_options_end(&ctx);
+
+	if (setup_revisions(argc, argv, &rev, NULL) != 1) {
+		error("unrecognized argument: %s", argv[1]);
+		usage_with_options(shortlog_usage, options);
 	}
-	init_revisions(&rev, prefix);
-	argc = setup_revisions(argc, argv, &rev, NULL);
-	if (argc > 1)
-		die ("unrecognized argument: %s", argv[1]);
 
 	/* assume HEAD if from a tty */
 	if (!nongit && !rev.pending.nr && isatty(0))
diff --git a/parse-options.c b/parse-options.c
index b8bde2b04a..469831d21b 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -1,17 +1,11 @@
 #include "git-compat-util.h"
 #include "parse-options.h"
+#include "cache.h"
 
 #define OPT_SHORT 1
 #define OPT_UNSET 2
 
-struct optparse_t {
-	const char **argv;
-	const char **out;
-	int argc, cpidx;
-	const char *opt;
-};
-
-static inline const char *get_arg(struct optparse_t *p)
+static inline const char *get_arg(struct parse_opt_ctx_t *p)
 {
 	if (p->opt) {
 		const char *res = p->opt;
@@ -37,7 +31,7 @@ static int opterror(const struct option *opt, const char *reason, int flags)
 	return error("option `%s' %s", opt->long_name, reason);
 }
 
-static int get_value(struct optparse_t *p,
+static int get_value(struct parse_opt_ctx_t *p,
                      const struct option *opt, int flags)
 {
 	const char *s, *arg;
@@ -101,14 +95,14 @@ static int get_value(struct optparse_t *p,
 
 	case OPTION_CALLBACK:
 		if (unset)
-			return (*opt->callback)(opt, NULL, 1);
+			return (*opt->callback)(opt, NULL, 1) ? (-1) : 0;
 		if (opt->flags & PARSE_OPT_NOARG)
-			return (*opt->callback)(opt, NULL, 0);
+			return (*opt->callback)(opt, NULL, 0) ? (-1) : 0;
 		if (opt->flags & PARSE_OPT_OPTARG && !p->opt)
-			return (*opt->callback)(opt, NULL, 0);
+			return (*opt->callback)(opt, NULL, 0) ? (-1) : 0;
 		if (!arg)
 			return opterror(opt, "requires a value", flags);
-		return (*opt->callback)(opt, get_arg(p), 0);
+		return (*opt->callback)(opt, get_arg(p), 0) ? (-1) : 0;
 
 	case OPTION_INTEGER:
 		if (unset) {
@@ -131,7 +125,7 @@ static int get_value(struct optparse_t *p,
 	}
 }
 
-static int parse_short_opt(struct optparse_t *p, const struct option *options)
+static int parse_short_opt(struct parse_opt_ctx_t *p, const struct option *options)
 {
 	for (; options->type != OPTION_END; options++) {
 		if (options->short_name == *p->opt) {
@@ -139,10 +133,10 @@ static int parse_short_opt(struct optparse_t *p, const struct option *options)
 			return get_value(p, options, OPT_SHORT);
 		}
 	}
-	return error("unknown switch `%c'", *p->opt);
+	return -2;
 }
 
-static int parse_long_opt(struct optparse_t *p, const char *arg,
+static int parse_long_opt(struct parse_opt_ctx_t *p, const char *arg,
                           const struct option *options)
 {
 	const char *arg_end = strchr(arg, '=');
@@ -224,7 +218,7 @@ is_abbreviated:
 			abbrev_option->long_name);
 	if (abbrev_option)
 		return get_value(p, abbrev_option, abbrev_flags);
-	return error("unknown option `%s'", arg);
+	return -2;
 }
 
 void check_typos(const char *arg, const struct option *options)
@@ -247,67 +241,126 @@ void check_typos(const char *arg, const struct option *options)
 	}
 }
 
-static NORETURN void usage_with_options_internal(const char * const *,
-                                                 const struct option *, int);
+void parse_options_start(struct parse_opt_ctx_t *ctx,
+			 int argc, const char **argv, int flags)
+{
+	memset(ctx, 0, sizeof(*ctx));
+	ctx->argc = argc - 1;
+	ctx->argv = argv + 1;
+	ctx->out  = argv;
+	ctx->cpidx = ((flags & PARSE_OPT_KEEP_ARGV0) != 0);
+	ctx->flags = flags;
+}
 
-int parse_options(int argc, const char **argv, const struct option *options,
-                  const char * const usagestr[], int flags)
+static int usage_with_options_internal(const char * const *,
+				       const struct option *, int);
+
+int parse_options_step(struct parse_opt_ctx_t *ctx,
+		       const struct option *options,
+		       const char * const usagestr[])
 {
-	struct optparse_t args = { argv + 1, argv, argc - 1, 0, NULL };
+	/* we must reset ->opt, unknown short option leave it dangling */
+	ctx->opt = NULL;
 
-	for (; args.argc; args.argc--, args.argv++) {
-		const char *arg = args.argv[0];
+	for (; ctx->argc; ctx->argc--, ctx->argv++) {
+		const char *arg = ctx->argv[0];
 
 		if (*arg != '-' || !arg[1]) {
-			if (flags & PARSE_OPT_STOP_AT_NON_OPTION)
+			if (ctx->flags & PARSE_OPT_STOP_AT_NON_OPTION)
 				break;
-			args.out[args.cpidx++] = args.argv[0];
+			ctx->out[ctx->cpidx++] = ctx->argv[0];
 			continue;
 		}
 
 		if (arg[1] != '-') {
-			args.opt = arg + 1;
-			if (*args.opt == 'h')
-				usage_with_options(usagestr, options);
-			if (parse_short_opt(&args, options) < 0)
-				usage_with_options(usagestr, options);
-			if (args.opt)
+			ctx->opt = arg + 1;
+			if (*ctx->opt == 'h')
+				return parse_options_usage(usagestr, options);
+			switch (parse_short_opt(ctx, options)) {
+			case -1:
+				return parse_options_usage(usagestr, options);
+			case -2:
+				return PARSE_OPT_UNKNOWN;
+			}
+			if (ctx->opt)
 				check_typos(arg + 1, options);
-			while (args.opt) {
-				if (*args.opt == 'h')
-					usage_with_options(usagestr, options);
-				if (parse_short_opt(&args, options) < 0)
-					usage_with_options(usagestr, options);
+			while (ctx->opt) {
+				if (*ctx->opt == 'h')
+					return parse_options_usage(usagestr, options);
+				switch (parse_short_opt(ctx, options)) {
+				case -1:
+					return parse_options_usage(usagestr, options);
+				case -2:
+					/* fake a short option thing to hide the fact that we may have
+					 * started to parse aggregated stuff
+					 *
+					 * This is leaky, too bad.
+					 */
+					ctx->argv[0] = xstrdup(ctx->opt - 1);
+					*(char *)ctx->argv[0] = '-';
+					return PARSE_OPT_UNKNOWN;
+				}
 			}
 			continue;
 		}
 
 		if (!arg[2]) { /* "--" */
-			if (!(flags & PARSE_OPT_KEEP_DASHDASH)) {
-				args.argc--;
-				args.argv++;
+			if (!(ctx->flags & PARSE_OPT_KEEP_DASHDASH)) {
+				ctx->argc--;
+				ctx->argv++;
 			}
 			break;
 		}
 
 		if (!strcmp(arg + 2, "help-all"))
-			usage_with_options_internal(usagestr, options, 1);
+			return usage_with_options_internal(usagestr, options, 1);
 		if (!strcmp(arg + 2, "help"))
-			usage_with_options(usagestr, options);
-		if (parse_long_opt(&args, arg + 2, options))
-			usage_with_options(usagestr, options);
+			return parse_options_usage(usagestr, options);
+		switch (parse_long_opt(ctx, arg + 2, options)) {
+		case -1:
+			return parse_options_usage(usagestr, options);
+		case -2:
+			return PARSE_OPT_UNKNOWN;
+		}
 	}
+	return PARSE_OPT_DONE;
+}
 
-	memmove(args.out + args.cpidx, args.argv, args.argc * sizeof(*args.out));
-	args.out[args.cpidx + args.argc] = NULL;
-	return args.cpidx + args.argc;
+int parse_options_end(struct parse_opt_ctx_t *ctx)
+{
+	memmove(ctx->out + ctx->cpidx, ctx->argv, ctx->argc * sizeof(*ctx->out));
+	ctx->out[ctx->cpidx + ctx->argc] = NULL;
+	return ctx->cpidx + ctx->argc;
+}
+
+int parse_options(int argc, const char **argv, const struct option *options,
+		  const char * const usagestr[], int flags)
+{
+	struct parse_opt_ctx_t ctx;
+
+	parse_options_start(&ctx, argc, argv, flags);
+	switch (parse_options_step(&ctx, options, usagestr)) {
+	case PARSE_OPT_HELP:
+		exit(129);
+	case PARSE_OPT_DONE:
+		break;
+	default: /* PARSE_OPT_UNKNOWN */
+		if (ctx.argv[0][1] == '-') {
+			error("unknown option `%s'", ctx.argv[0] + 2);
+		} else {
+			error("unknown switch `%c'", *ctx.opt);
+		}
+		usage_with_options(usagestr, options);
+	}
+
+	return parse_options_end(&ctx);
 }
 
 #define USAGE_OPTS_WIDTH 24
 #define USAGE_GAP         2
 
-void usage_with_options_internal(const char * const *usagestr,
-                                 const struct option *opts, int full)
+int usage_with_options_internal(const char * const *usagestr,
+				const struct option *opts, int full)
 {
 	fprintf(stderr, "usage: %s\n", *usagestr++);
 	while (*usagestr && **usagestr)
@@ -392,15 +445,23 @@ void usage_with_options_internal(const char * const *usagestr,
 	}
 	fputc('\n', stderr);
 
-	exit(129);
+	return PARSE_OPT_HELP;
 }
 
 void usage_with_options(const char * const *usagestr,
-                        const struct option *opts)
+			const struct option *opts)
 {
 	usage_with_options_internal(usagestr, opts, 0);
+	exit(129);
+}
+
+int parse_options_usage(const char * const *usagestr,
+			const struct option *opts)
+{
+	return usage_with_options_internal(usagestr, opts, 0);
 }
 
+
 /*----- some often used options -----*/
 #include "cache.h"
 
diff --git a/parse-options.h b/parse-options.h
index 4ee443dafe..c5f0b4b4da 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -20,6 +20,7 @@ enum parse_opt_type {
 enum parse_opt_flags {
 	PARSE_OPT_KEEP_DASHDASH = 1,
 	PARSE_OPT_STOP_AT_NON_OPTION = 2,
+	PARSE_OPT_KEEP_ARGV0 = 4,
 };
 
 enum parse_opt_option_flags {
@@ -111,6 +112,40 @@ extern int parse_options(int argc, const char **argv,
 extern NORETURN void usage_with_options(const char * const *usagestr,
                                         const struct option *options);
 
+/*----- incremantal advanced APIs -----*/
+
+enum {
+	PARSE_OPT_HELP = -1,
+	PARSE_OPT_DONE,
+	PARSE_OPT_UNKNOWN,
+};
+
+/*
+ * It's okay for the caller to consume argv/argc in the usual way.
+ * Other fields of that structure are private to parse-options and should not
+ * be modified in any way.
+ */
+struct parse_opt_ctx_t {
+	const char **argv;
+	const char **out;
+	int argc, cpidx;
+	const char *opt;
+	int flags;
+};
+
+extern int parse_options_usage(const char * const *usagestr,
+			       const struct option *opts);
+
+extern void parse_options_start(struct parse_opt_ctx_t *ctx,
+				int argc, const char **argv, int flags);
+
+extern int parse_options_step(struct parse_opt_ctx_t *ctx,
+			      const struct option *options,
+			      const char * const usagestr[]);
+
+extern int parse_options_end(struct parse_opt_ctx_t *ctx);
+
+
 /*----- some often used options -----*/
 extern int parse_opt_abbrev_cb(const struct option *, const char *, int);
 extern int parse_opt_approxidate_cb(const struct option *, const char *, int);
diff --git a/revision.c b/revision.c
index 6ce6042a63..bbd563e651 100644
--- a/revision.c
+++ b/revision.c
@@ -10,6 +10,7 @@
 #include "grep.h"
 #include "reflog-walk.h"
 #include "patch-ids.h"
+#include "decorate.h"
 
 volatile show_early_output_fn_t show_early_output;
 
@@ -973,6 +974,226 @@ static void add_ignore_packed(struct rev_info *revs, const char *name)
 	revs->ignore_packed[num] = NULL;
 }
 
+static int handle_revision_opt(struct rev_info *revs, int argc, const char **argv,
+			       int *unkc, const char **unkv)
+{
+	const char *arg = argv[0];
+
+	/* pseudo revision arguments */
+	if (!strcmp(arg, "--all") || !strcmp(arg, "--branches") ||
+	    !strcmp(arg, "--tags") || !strcmp(arg, "--remotes") ||
+	    !strcmp(arg, "--reflog") || !strcmp(arg, "--not") ||
+	    !strcmp(arg, "--no-walk") || !strcmp(arg, "--do-walk"))
+	{
+		unkv[(*unkc)++] = arg;
+		return 0;
+	}
+
+	if (!prefixcmp(arg, "--max-count=")) {
+		revs->max_count = atoi(arg + 12);
+	} else if (!prefixcmp(arg, "--skip=")) {
+		revs->skip_count = atoi(arg + 7);
+	} else if ((*arg == '-') && isdigit(arg[1])) {
+	/* accept -<digit>, like traditional "head" */
+		revs->max_count = atoi(arg + 1);
+	} else if (!strcmp(arg, "-n")) {
+		if (argc <= 1)
+			return error("-n requires an argument");
+		revs->max_count = atoi(argv[1]);
+		return 2;
+	} else if (!prefixcmp(arg, "-n")) {
+		revs->max_count = atoi(arg + 2);
+	} else if (!prefixcmp(arg, "--max-age=")) {
+		revs->max_age = atoi(arg + 10);
+	} else if (!prefixcmp(arg, "--since=")) {
+		revs->max_age = approxidate(arg + 8);
+	} else if (!prefixcmp(arg, "--after=")) {
+		revs->max_age = approxidate(arg + 8);
+	} else if (!prefixcmp(arg, "--min-age=")) {
+		revs->min_age = atoi(arg + 10);
+	} else if (!prefixcmp(arg, "--before=")) {
+		revs->min_age = approxidate(arg + 9);
+	} else if (!prefixcmp(arg, "--until=")) {
+		revs->min_age = approxidate(arg + 8);
+	} else if (!strcmp(arg, "--first-parent")) {
+		revs->first_parent_only = 1;
+	} else if (!strcmp(arg, "-g") || !strcmp(arg, "--walk-reflogs")) {
+		init_reflog_walk(&revs->reflog_info);
+	} else if (!strcmp(arg, "--default")) {
+		if (argc <= 1)
+			return error("bad --default argument");
+		revs->def = argv[1];
+		return 2;
+	} else if (!strcmp(arg, "--merge")) {
+		revs->show_merge = 1;
+	} else if (!strcmp(arg, "--topo-order")) {
+		revs->lifo = 1;
+		revs->topo_order = 1;
+	} else if (!strcmp(arg, "--date-order")) {
+		revs->lifo = 0;
+		revs->topo_order = 1;
+	} else if (!prefixcmp(arg, "--early-output")) {
+		int count = 100;
+		switch (arg[14]) {
+		case '=':
+			count = atoi(arg+15);
+			/* Fallthrough */
+		case 0:
+			revs->topo_order = 1;
+		       revs->early_output = count;
+		}
+	} else if (!strcmp(arg, "--parents")) {
+		revs->rewrite_parents = 1;
+		revs->print_parents = 1;
+	} else if (!strcmp(arg, "--dense")) {
+		revs->dense = 1;
+	} else if (!strcmp(arg, "--sparse")) {
+		revs->dense = 0;
+	} else if (!strcmp(arg, "--show-all")) {
+		revs->show_all = 1;
+	} else if (!strcmp(arg, "--remove-empty")) {
+		revs->remove_empty_trees = 1;
+	} else if (!strcmp(arg, "--no-merges")) {
+		revs->no_merges = 1;
+	} else if (!strcmp(arg, "--boundary")) {
+		revs->boundary = 1;
+	} else if (!strcmp(arg, "--left-right")) {
+		revs->left_right = 1;
+	} else if (!strcmp(arg, "--cherry-pick")) {
+		revs->cherry_pick = 1;
+		revs->limited = 1;
+	} else if (!strcmp(arg, "--objects")) {
+		revs->tag_objects = 1;
+		revs->tree_objects = 1;
+		revs->blob_objects = 1;
+	} else if (!strcmp(arg, "--objects-edge")) {
+		revs->tag_objects = 1;
+		revs->tree_objects = 1;
+		revs->blob_objects = 1;
+		revs->edge_hint = 1;
+	} else if (!strcmp(arg, "--unpacked")) {
+		revs->unpacked = 1;
+		free(revs->ignore_packed);
+		revs->ignore_packed = NULL;
+		revs->num_ignore_packed = 0;
+	} else if (!prefixcmp(arg, "--unpacked=")) {
+		revs->unpacked = 1;
+		add_ignore_packed(revs, arg+11);
+	} else if (!strcmp(arg, "-r")) {
+		revs->diff = 1;
+		DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
+	} else if (!strcmp(arg, "-t")) {
+		revs->diff = 1;
+		DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
+		DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
+	} else if (!strcmp(arg, "-m")) {
+		revs->ignore_merges = 0;
+	} else if (!strcmp(arg, "-c")) {
+		revs->diff = 1;
+		revs->dense_combined_merges = 0;
+		revs->combine_merges = 1;
+	} else if (!strcmp(arg, "--cc")) {
+		revs->diff = 1;
+		revs->dense_combined_merges = 1;
+		revs->combine_merges = 1;
+	} else if (!strcmp(arg, "-v")) {
+		revs->verbose_header = 1;
+	} else if (!strcmp(arg, "--pretty")) {
+		revs->verbose_header = 1;
+		get_commit_format(arg+8, revs);
+	} else if (!prefixcmp(arg, "--pretty=")) {
+		revs->verbose_header = 1;
+		get_commit_format(arg+9, revs);
+	} else if (!strcmp(arg, "--graph")) {
+		revs->topo_order = 1;
+		revs->rewrite_parents = 1;
+		revs->graph = graph_init(revs);
+	} else if (!strcmp(arg, "--root")) {
+		revs->show_root_diff = 1;
+	} else if (!strcmp(arg, "--no-commit-id")) {
+		revs->no_commit_id = 1;
+	} else if (!strcmp(arg, "--always")) {
+		revs->always_show_header = 1;
+	} else if (!strcmp(arg, "--no-abbrev")) {
+		revs->abbrev = 0;
+	} else if (!strcmp(arg, "--abbrev")) {
+		revs->abbrev = DEFAULT_ABBREV;
+	} else if (!prefixcmp(arg, "--abbrev=")) {
+		revs->abbrev = strtoul(arg + 9, NULL, 10);
+		if (revs->abbrev < MINIMUM_ABBREV)
+			revs->abbrev = MINIMUM_ABBREV;
+		else if (revs->abbrev > 40)
+			revs->abbrev = 40;
+	} else if (!strcmp(arg, "--abbrev-commit")) {
+		revs->abbrev_commit = 1;
+	} else if (!strcmp(arg, "--full-diff")) {
+		revs->diff = 1;
+		revs->full_diff = 1;
+	} else if (!strcmp(arg, "--full-history")) {
+		revs->simplify_history = 0;
+	} else if (!strcmp(arg, "--relative-date")) {
+		revs->date_mode = DATE_RELATIVE;
+	} else if (!strncmp(arg, "--date=", 7)) {
+		revs->date_mode = parse_date_format(arg + 7);
+	} else if (!strcmp(arg, "--log-size")) {
+		revs->show_log_size = 1;
+	}
+	/*
+	 * Grepping the commit log
+	 */
+	else if (!prefixcmp(arg, "--author=")) {
+		add_header_grep(revs, "author", arg+9);
+	} else if (!prefixcmp(arg, "--committer=")) {
+		add_header_grep(revs, "committer", arg+12);
+	} else if (!prefixcmp(arg, "--grep=")) {
+		add_message_grep(revs, arg+7);
+	} else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
+		if (revs->grep_filter)
+			revs->grep_filter->regflags |= REG_EXTENDED;
+	} else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
+		if (revs->grep_filter)
+			revs->grep_filter->regflags |= REG_ICASE;
+	} else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
+		if (revs->grep_filter)
+			revs->grep_filter->fixed = 1;
+	} else if (!strcmp(arg, "--all-match")) {
+		if (revs->grep_filter)
+			revs->grep_filter->all_match = 1;
+	} else if (!prefixcmp(arg, "--encoding=")) {
+		arg += 11;
+		if (strcmp(arg, "none"))
+			git_log_output_encoding = xstrdup(arg);
+		else
+			git_log_output_encoding = "";
+	} else if (!strcmp(arg, "--reverse")) {
+		revs->reverse ^= 1;
+	} else if (!strcmp(arg, "--children")) {
+		revs->children.name = "children";
+		revs->limited = 1;
+	} else {
+		int opts = diff_opt_parse(&revs->diffopt, argv, argc);
+		if (!opts)
+			unkv[(*unkc)++] = arg;
+		return opts;
+	}
+
+	return 1;
+}
+
+void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
+			const struct option *options,
+			const char * const usagestr[])
+{
+	int n = handle_revision_opt(revs, ctx->argc, ctx->argv,
+				    &ctx->cpidx, ctx->out);
+	if (n <= 0) {
+		error("unknown option `%s'", ctx->argv[0]);
+		usage_with_options(usagestr, options);
+	}
+	ctx->argv += n;
+	ctx->argc -= n;
+}
+
 /*
  * Parse revision information, filling in the "rev_info" structure,
  * and removing the used arguments from the argument list.
@@ -982,12 +1203,7 @@ static void add_ignore_packed(struct rev_info *revs, const char *name)
  */
 int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def)
 {
-	int i, flags, seen_dashdash, show_merge;
-	const char **unrecognized = argv + 1;
-	int left = 1;
-	int all_match = 0;
-	int regflags = 0;
-	int fixed = 0;
+	int i, flags, left, seen_dashdash;
 
 	/* First, search for "--" */
 	seen_dashdash = 0;
@@ -1003,58 +1219,13 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 		break;
 	}
 
-	flags = show_merge = 0;
-	for (i = 1; i < argc; i++) {
+	/* Second, deal with arguments and options */
+	flags = 0;
+	for (left = i = 1; i < argc; i++) {
 		const char *arg = argv[i];
 		if (*arg == '-') {
 			int opts;
-			if (!prefixcmp(arg, "--max-count=")) {
-				revs->max_count = atoi(arg + 12);
-				continue;
-			}
-			if (!prefixcmp(arg, "--skip=")) {
-				revs->skip_count = atoi(arg + 7);
-				continue;
-			}
-			/* accept -<digit>, like traditional "head" */
-			if ((*arg == '-') && isdigit(arg[1])) {
-				revs->max_count = atoi(arg + 1);
-				continue;
-			}
-			if (!strcmp(arg, "-n")) {
-				if (argc <= i + 1)
-					die("-n requires an argument");
-				revs->max_count = atoi(argv[++i]);
-				continue;
-			}
-			if (!prefixcmp(arg, "-n")) {
-				revs->max_count = atoi(arg + 2);
-				continue;
-			}
-			if (!prefixcmp(arg, "--max-age=")) {
-				revs->max_age = atoi(arg + 10);
-				continue;
-			}
-			if (!prefixcmp(arg, "--since=")) {
-				revs->max_age = approxidate(arg + 8);
-				continue;
-			}
-			if (!prefixcmp(arg, "--after=")) {
-				revs->max_age = approxidate(arg + 8);
-				continue;
-			}
-			if (!prefixcmp(arg, "--min-age=")) {
-				revs->min_age = atoi(arg + 10);
-				continue;
-			}
-			if (!prefixcmp(arg, "--before=")) {
-				revs->min_age = approxidate(arg + 9);
-				continue;
-			}
-			if (!prefixcmp(arg, "--until=")) {
-				revs->min_age = approxidate(arg + 8);
-				continue;
-			}
+
 			if (!strcmp(arg, "--all")) {
 				handle_refs(revs, flags, for_each_ref);
 				continue;
@@ -1071,265 +1242,14 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 				handle_refs(revs, flags, for_each_remote_ref);
 				continue;
 			}
-			if (!strcmp(arg, "--first-parent")) {
-				revs->first_parent_only = 1;
-				continue;
-			}
 			if (!strcmp(arg, "--reflog")) {
 				handle_reflog(revs, flags);
 				continue;
 			}
-			if (!strcmp(arg, "-g") ||
-					!strcmp(arg, "--walk-reflogs")) {
-				init_reflog_walk(&revs->reflog_info);
-				continue;
-			}
 			if (!strcmp(arg, "--not")) {
 				flags ^= UNINTERESTING;
 				continue;
 			}
-			if (!strcmp(arg, "--default")) {
-				if (++i >= argc)
-					die("bad --default argument");
-				def = argv[i];
-				continue;
-			}
-			if (!strcmp(arg, "--merge")) {
-				show_merge = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--topo-order")) {
-				revs->lifo = 1;
-				revs->topo_order = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--date-order")) {
-				revs->lifo = 0;
-				revs->topo_order = 1;
-				continue;
-			}
-			if (!prefixcmp(arg, "--early-output")) {
-				int count = 100;
-				switch (arg[14]) {
-				case '=':
-					count = atoi(arg+15);
-					/* Fallthrough */
-				case 0:
-					revs->topo_order = 1;
-					revs->early_output = count;
-					continue;
-				}
-			}
-			if (!strcmp(arg, "--parents")) {
-				revs->rewrite_parents = 1;
-				revs->print_parents = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--dense")) {
-				revs->dense = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--sparse")) {
-				revs->dense = 0;
-				continue;
-			}
-			if (!strcmp(arg, "--show-all")) {
-				revs->show_all = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--remove-empty")) {
-				revs->remove_empty_trees = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--no-merges")) {
-				revs->no_merges = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--boundary")) {
-				revs->boundary = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--left-right")) {
-				revs->left_right = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--cherry-pick")) {
-				revs->cherry_pick = 1;
-				revs->limited = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--objects")) {
-				revs->tag_objects = 1;
-				revs->tree_objects = 1;
-				revs->blob_objects = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--objects-edge")) {
-				revs->tag_objects = 1;
-				revs->tree_objects = 1;
-				revs->blob_objects = 1;
-				revs->edge_hint = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--unpacked")) {
-				revs->unpacked = 1;
-				free(revs->ignore_packed);
-				revs->ignore_packed = NULL;
-				revs->num_ignore_packed = 0;
-				continue;
-			}
-			if (!prefixcmp(arg, "--unpacked=")) {
-				revs->unpacked = 1;
-				add_ignore_packed(revs, arg+11);
-				continue;
-			}
-			if (!strcmp(arg, "-r")) {
-				revs->diff = 1;
-				DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
-				continue;
-			}
-			if (!strcmp(arg, "-t")) {
-				revs->diff = 1;
-				DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
-				DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
-				continue;
-			}
-			if (!strcmp(arg, "-m")) {
-				revs->ignore_merges = 0;
-				continue;
-			}
-			if (!strcmp(arg, "-c")) {
-				revs->diff = 1;
-				revs->dense_combined_merges = 0;
-				revs->combine_merges = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--cc")) {
-				revs->diff = 1;
-				revs->dense_combined_merges = 1;
-				revs->combine_merges = 1;
-				continue;
-			}
-			if (!strcmp(arg, "-v")) {
-				revs->verbose_header = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--pretty")) {
-				revs->verbose_header = 1;
-				get_commit_format(arg+8, revs);
-				continue;
-			}
-			if (!prefixcmp(arg, "--pretty=")) {
-				revs->verbose_header = 1;
-				get_commit_format(arg+9, revs);
-				continue;
-			}
-			if (!strcmp(arg, "--graph")) {
-				revs->topo_order = 1;
-				revs->rewrite_parents = 1;
-				revs->graph = graph_init(revs);
-				continue;
-			}
-			if (!strcmp(arg, "--root")) {
-				revs->show_root_diff = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--no-commit-id")) {
-				revs->no_commit_id = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--always")) {
-				revs->always_show_header = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--no-abbrev")) {
-				revs->abbrev = 0;
-				continue;
-			}
-			if (!strcmp(arg, "--abbrev")) {
-				revs->abbrev = DEFAULT_ABBREV;
-				continue;
-			}
-			if (!prefixcmp(arg, "--abbrev=")) {
-				revs->abbrev = strtoul(arg + 9, NULL, 10);
-				if (revs->abbrev < MINIMUM_ABBREV)
-					revs->abbrev = MINIMUM_ABBREV;
-				else if (revs->abbrev > 40)
-					revs->abbrev = 40;
-				continue;
-			}
-			if (!strcmp(arg, "--abbrev-commit")) {
-				revs->abbrev_commit = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--full-diff")) {
-				revs->diff = 1;
-				revs->full_diff = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--full-history")) {
-				revs->simplify_history = 0;
-				continue;
-			}
-			if (!strcmp(arg, "--relative-date")) {
-				revs->date_mode = DATE_RELATIVE;
-				continue;
-			}
-			if (!strncmp(arg, "--date=", 7)) {
-				revs->date_mode = parse_date_format(arg + 7);
-				continue;
-			}
-			if (!strcmp(arg, "--log-size")) {
-				revs->show_log_size = 1;
-				continue;
-			}
-
-			/*
-			 * Grepping the commit log
-			 */
-			if (!prefixcmp(arg, "--author=")) {
-				add_header_grep(revs, "author", arg+9);
-				continue;
-			}
-			if (!prefixcmp(arg, "--committer=")) {
-				add_header_grep(revs, "committer", arg+12);
-				continue;
-			}
-			if (!prefixcmp(arg, "--grep=")) {
-				add_message_grep(revs, arg+7);
-				continue;
-			}
-			if (!strcmp(arg, "--extended-regexp") ||
-			    !strcmp(arg, "-E")) {
-				regflags |= REG_EXTENDED;
-				continue;
-			}
-			if (!strcmp(arg, "--regexp-ignore-case") ||
-			    !strcmp(arg, "-i")) {
-				regflags |= REG_ICASE;
-				continue;
-			}
-			if (!strcmp(arg, "--fixed-strings") ||
-			    !strcmp(arg, "-F")) {
-				fixed = 1;
-				continue;
-			}
-			if (!strcmp(arg, "--all-match")) {
-				all_match = 1;
-				continue;
-			}
-			if (!prefixcmp(arg, "--encoding=")) {
-				arg += 11;
-				if (strcmp(arg, "none"))
-					git_log_output_encoding = xstrdup(arg);
-				else
-					git_log_output_encoding = "";
-				continue;
-			}
-			if (!strcmp(arg, "--reverse")) {
-				revs->reverse ^= 1;
-				continue;
-			}
 			if (!strcmp(arg, "--no-walk")) {
 				revs->no_walk = 1;
 				continue;
@@ -1339,13 +1259,13 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 				continue;
 			}
 
-			opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
+			opts = handle_revision_opt(revs, argc - i, argv + i, &left, argv);
 			if (opts > 0) {
 				i += opts - 1;
 				continue;
 			}
-			*unrecognized++ = arg;
-			left++;
+			if (opts < 0)
+				exit(128);
 			continue;
 		}
 
@@ -1369,21 +1289,18 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 		}
 	}
 
-	if (revs->grep_filter) {
-		revs->grep_filter->regflags |= regflags;
-		revs->grep_filter->fixed = fixed;
-	}
-
-	if (show_merge)
+	if (revs->def == NULL)
+		revs->def = def;
+	if (revs->show_merge)
 		prepare_show_merge(revs);
-	if (def && !revs->pending.nr) {
+	if (revs->def && !revs->pending.nr) {
 		unsigned char sha1[20];
 		struct object *object;
 		unsigned mode;
-		if (get_sha1_with_mode(def, sha1, &mode))
-			die("bad default revision '%s'", def);
-		object = get_reference(revs, def, sha1, 0);
-		add_pending_object_with_mode(revs, object, def, mode);
+		if (get_sha1_with_mode(revs->def, sha1, &mode))
+			die("bad default revision '%s'", revs->def);
+		object = get_reference(revs, revs->def, sha1, 0);
+		add_pending_object_with_mode(revs, object, revs->def, mode);
 	}
 
 	/* Did the user ask for any diff output? Run the diff! */
@@ -1417,12 +1334,13 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 		die("diff_setup_done failed");
 
 	if (revs->grep_filter) {
-		revs->grep_filter->all_match = all_match;
 		compile_grep_patterns(revs->grep_filter);
 	}
 
 	if (revs->reverse && revs->reflog_info)
 		die("cannot combine --reverse with --walk-reflogs");
+	if (revs->rewrite_parents && revs->children.name)
+		die("cannot combine --parents and --children");
 
 	/*
 	 * Limitations on the graph functionality
@@ -1436,6 +1354,26 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 	return left;
 }
 
+static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
+{
+	struct commit_list *l = xcalloc(1, sizeof(*l));
+
+	l->item = child;
+	l->next = add_decoration(&revs->children, &parent->object, l);
+}
+
+static void set_children(struct rev_info *revs)
+{
+	struct commit_list *l;
+	for (l = revs->commits; l; l = l->next) {
+		struct commit *commit = l->item;
+		struct commit_list *p;
+
+		for (p = commit->parents; p; p = p->next)
+			add_child(revs, p->item, commit);
+	}
+}
+
 int prepare_revision_walk(struct rev_info *revs)
 {
 	int nr = revs->pending.nr;
@@ -1464,6 +1402,8 @@ int prepare_revision_walk(struct rev_info *revs)
 			return -1;
 	if (revs->topo_order)
 		sort_in_topological_order(&revs->commits, revs->lifo);
+	if (revs->children.name)
+		set_children(revs);
 	return 0;
 }
 
@@ -1541,6 +1481,11 @@ static int commit_match(struct commit *commit, struct rev_info *opt)
 			   commit->buffer, strlen(commit->buffer));
 }
 
+static inline int want_ancestry(struct rev_info *revs)
+{
+	return (revs->rewrite_parents || revs->children.name);
+}
+
 enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
 {
 	if (commit->object.flags & SHOWN)
@@ -1561,13 +1506,13 @@ enum commit_action simplify_commit(struct rev_info *revs, struct commit *commit)
 		/* Commit without changes? */
 		if (commit->object.flags & TREESAME) {
 			/* drop merges unless we want parenthood */
-			if (!revs->rewrite_parents)
+			if (!want_ancestry(revs))
 				return commit_ignore;
 			/* non-merge - always ignore it */
 			if (!commit->parents || !commit->parents->next)
 				return commit_ignore;
 		}
-		if (revs->rewrite_parents && rewrite_parents(revs, commit) < 0)
+		if (want_ancestry(revs) && rewrite_parents(revs, commit) < 0)
 			return commit_error;
 	}
 	return commit_show;
diff --git a/revision.h b/revision.h
index f57b6c5d9a..fa68c65142 100644
--- a/revision.h
+++ b/revision.h
@@ -1,6 +1,8 @@
 #ifndef REVISION_H
 #define REVISION_H
 
+#include "parse-options.h"
+
 #define SEEN		(1u<<0)
 #define UNINTERESTING   (1u<<1)
 #define TREESAME	(1u<<2)
@@ -26,6 +28,7 @@ struct rev_info {
 
 	/* Basic information */
 	const char *prefix;
+	const char *def;
 	void *prune_data;
 	unsigned int early_output;
 
@@ -66,6 +69,7 @@ struct rev_info {
 
 	/* Format info */
 	unsigned int	shown_one:1,
+			show_merge:1,
 			abbrev_commit:1,
 			use_terminator:1,
 			missing_newline:1;
@@ -105,6 +109,7 @@ struct rev_info {
 	struct diff_options pruning;
 
 	struct reflog_walk_info *reflog_info;
+	struct decoration children;
 };
 
 #define REV_TREE_SAME		0
@@ -119,6 +124,9 @@ volatile show_early_output_fn_t show_early_output;
 
 extern void init_revisions(struct rev_info *revs, const char *prefix);
 extern int setup_revisions(int argc, const char **argv, struct rev_info *revs, const char *def);
+extern void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
+				 const struct option *options,
+				 const char * const usagestr[]);
 extern int handle_revision_arg(const char *arg, struct rev_info *revs,int flags,int cant_be_filename);
 
 extern int prepare_revision_walk(struct rev_info *revs);