Merge branch 'lt/logopt' into next

* lt/logopt:
  Tentative built-in "git show"
  Built-in git-whatchanged.
  rev-list option parser fix.
  Split init_revisions() out of setup_revisions()

9 files changed, 289 insertions, 343 deletions

diff --git a/commit.h b/commit.h
index 918c9ab5e4..de142afe73 100644
--- a/commit.h
+++ b/commit.h
@@ -45,6 +45,8 @@ enum cmit_fmt {
 	CMIT_FMT_FULL,
 	CMIT_FMT_FULLER,
 	CMIT_FMT_ONELINE,
+
+	CMIT_FMT_UNSPECIFIED,
 };
 
 extern enum cmit_fmt get_commit_format(const char *arg);
diff --git a/diff-tree.c b/diff-tree.c
index 7015b06c7f..e578798537 100644
--- a/diff-tree.c
+++ b/diff-tree.c
@@ -3,7 +3,7 @@
 #include "commit.h"
 #include "log-tree.h"
 
-static struct log_tree_opt log_tree_opt;
+static struct rev_info log_tree_opt;
 
 static int diff_tree_commit_sha1(const unsigned char *sha1)
 {
@@ -62,47 +62,20 @@ int main(int argc, const char **argv)
 {
 	int nr_sha1;
 	char line[1000];
-	unsigned char sha1[2][20];
-	const char *prefix = setup_git_directory();
-	static struct log_tree_opt *opt = &log_tree_opt;
+	struct object *tree1, *tree2;
+	static struct rev_info *opt = &log_tree_opt;
+	struct object_list *list;
 	int read_stdin = 0;
 
 	git_config(git_diff_config);
 	nr_sha1 = 0;
-	init_log_tree_opt(opt);
+	init_revisions(opt);
+	opt->abbrev = 0;
+	argc = setup_revisions(argc, argv, opt, NULL);
 
-	for (;;) {
-		int opt_cnt;
-		const char *arg;
+	while (--argc > 0) {
+		const char *arg = *++argv;
 
-		argv++;
-		argc--;
-		arg = *argv;
-		if (!arg)
-			break;
-
-		if (*arg != '-') {
-			if (nr_sha1 < 2 && !get_sha1(arg, sha1[nr_sha1])) {
-				nr_sha1++;
-				continue;
-			}
-			break;
-		}
-
-		opt_cnt = log_tree_opt_parse(opt, argv, argc);
-		if (opt_cnt < 0)
-			usage(diff_tree_usage);
-		else if (opt_cnt) {
-			argv += opt_cnt - 1;
-			argc -= opt_cnt - 1;
-			continue;
-		}
-
-		if (!strcmp(arg, "--")) {
-			argv++;
-			argc--;
-			break;
-		}
 		if (!strcmp(arg, "--stdin")) {
 			read_stdin = 1;
 			continue;
@@ -110,18 +83,36 @@ int main(int argc, const char **argv)
 		usage(diff_tree_usage);
 	}
 
-	if (opt->combine_merges)
-		opt->ignore_merges = 0;
-
-	/* We can only do dense combined merges with diff output */
-	if (opt->dense_combined_merges)
-		opt->diffopt.output_format = DIFF_FORMAT_PATCH;
-
-	if (opt->diffopt.output_format == DIFF_FORMAT_PATCH)
-		opt->diffopt.recursive = 1;
-
-	diff_tree_setup_paths(get_pathspec(prefix, argv), &opt->diffopt);
-	diff_setup_done(&opt->diffopt);
+	/*
+	 * NOTE! "setup_revisions()" will have inserted the revisions
+	 * it parsed in reverse order. So if you do
+	 *
+	 *	git-diff-tree a b
+	 *
+	 * the commit list will be "b" -> "a" -> NULL, so we reverse
+	 * the order of the objects if the first one is not marked
+	 * UNINTERESTING.
+	 */
+	nr_sha1 = 0;
+	list = opt->pending_objects;
+	if (list) {
+		nr_sha1++;
+		tree1 = list->item;
+		list = list->next;
+		if (list) {
+			nr_sha1++;
+			tree2 = tree1;
+			tree1 = list->item;
+			if (list->next)
+				usage(diff_tree_usage);
+			/* Switch them around if the second one was uninteresting.. */
+			if (tree2->flags & UNINTERESTING) {
+				struct object *tmp = tree2;
+				tree2 = tree1;
+				tree1 = tmp;
+			}
+		}
+	}
 
 	switch (nr_sha1) {
 	case 0:
@@ -129,10 +120,12 @@ int main(int argc, const char **argv)
 			usage(diff_tree_usage);
 		break;
 	case 1:
-		diff_tree_commit_sha1(sha1[0]);
+		diff_tree_commit_sha1(tree1->sha1);
 		break;
 	case 2:
-		diff_tree_sha1(sha1[0], sha1[1], "", &opt->diffopt);
+		diff_tree_sha1(tree1->sha1,
+			       tree2->sha1,
+			       "", &opt->diffopt);
 		log_tree_diff_flush(opt);
 		break;
 	}
diff --git a/git.c b/git.c
index 2e0ae5e58e..239b26adfd 100644
--- a/git.c
+++ b/git.c
@@ -279,31 +279,28 @@ static int cmd_help(int argc, const char **argv, char **envp)
 #define LOGSIZE (65536)
 
 static int cmd_log_wc(int argc, const char **argv, char **envp,
-		      struct whatchanged_opt *wcopt)
+		      struct rev_info *rev)
 {
 	struct commit *commit;
 	char *buf = xmalloc(LOGSIZE);
 	const char *commit_prefix = "commit ";
 	int shown = 0;
-	struct rev_info *rev = &wcopt->revopt;
-	struct log_tree_opt *opt = &wcopt->logopt;
 
-	opt->commit_format = CMIT_FMT_DEFAULT;
-	wcopt->abbrev = DEFAULT_ABBREV;
-	argc = parse_whatchanged_opt(argc, argv, wcopt);
-
-	if (opt->commit_format == CMIT_FMT_ONELINE)
+	if (argc > 1)
+		die("unrecognized argument: %s", argv[1]);
+	if (rev->commit_format == CMIT_FMT_ONELINE)
 		commit_prefix = "";
 
 	prepare_revision_walk(rev);
 	setup_pager();
 	while ((commit = get_revision(rev)) != NULL) {
-		if (shown && wcopt->do_diff &&
-		    opt->commit_format != CMIT_FMT_ONELINE)
+		if (shown && rev->diff &&
+		    rev->commit_format != CMIT_FMT_ONELINE)
 			putchar('\n');
 		fputs(commit_prefix, stdout);
-		if (wcopt->abbrev_commit && wcopt->abbrev)
-			fputs(find_unique_abbrev(commit->object.sha1, wcopt->abbrev),
+		if (rev->abbrev_commit && rev->abbrev)
+			fputs(find_unique_abbrev(commit->object.sha1,
+						 rev->abbrev),
 			      stdout);
 		else
 			fputs(sha1_to_hex(commit->object.sha1), stdout);
@@ -326,16 +323,16 @@ static int cmd_log_wc(int argc, const char **argv, char **envp,
 			     parents = parents->next)
 				parents->item->object.flags &= ~TMP_MARK;
 		}
-		if (opt->commit_format == CMIT_FMT_ONELINE)
+		if (rev->commit_format == CMIT_FMT_ONELINE)
 			putchar(' ');
 		else
 			putchar('\n');
-		pretty_print_commit(opt->commit_format, commit, ~0, buf,
-				    LOGSIZE, wcopt->abbrev);
+		pretty_print_commit(rev->commit_format, commit, ~0, buf,
+				    LOGSIZE, rev->abbrev);
 		printf("%s\n", buf);
-		if (wcopt->do_diff) {
-			printf("---\n");
-			log_tree_commit(opt, commit);
+		if (rev->diff) {
+			printf("--\n");
+			log_tree_commit(rev, commit);
 		}
 		shown = 1;
 		free(commit->buffer);
@@ -345,38 +342,47 @@ static int cmd_log_wc(int argc, const char **argv, char **envp,
 	return 0;
 }
 
-static int cmd_log(int ac, const char **av, char **ep)
+static int cmd_wc(int argc, const char **argv, char **envp)
 {
-	struct whatchanged_opt wcopt;
-
-	memset(&wcopt, 0, sizeof(wcopt));
-	init_log_tree_opt(&wcopt.logopt);
-	return cmd_log_wc(ac, av, ep, &wcopt);
+	struct rev_info rev;
+
+	init_revisions(&rev);
+	rev.abbrev = DEFAULT_ABBREV;
+	rev.no_commit_id = 1;
+	rev.commit_format = CMIT_FMT_DEFAULT;
+	rev.diff = 1;
+	rev.diffopt.recursive = 1;
+	argc = setup_revisions(argc, argv, &rev, "HEAD");
+	return cmd_log_wc(argc, argv, envp, &rev);
 }
 
-static int cmd_whatchanged(int ac, const char **av, char **ep)
+static int cmd_show(int argc, const char **argv, char **envp)
 {
-	struct whatchanged_opt wcopt;
-
-	memset(&wcopt, 0, sizeof(wcopt));
-	wcopt.do_diff = 1;
-	init_log_tree_opt(&wcopt.logopt);
-	wcopt.logopt.diffopt.recursive = 1;
-	return cmd_log_wc(ac, av, ep, &wcopt);
+	struct rev_info rev;
+
+	init_revisions(&rev);
+	rev.diff = 1;
+	rev.ignore_merges = 0;
+	rev.combine_merges = 1;
+	rev.dense_combined_merges = 1;
+	rev.abbrev = DEFAULT_ABBREV;
+	rev.commit_format = CMIT_FMT_DEFAULT;
+	rev.diffopt.recursive = 1;
+	rev.no_walk = 1;
+	argc = setup_revisions(argc, argv, &rev, "HEAD");
+	return cmd_log_wc(argc, argv, envp, &rev);
 }
 
-static int cmd_show(int ac, const char **av, char **ep)
+static int cmd_log(int argc, const char **argv, char **envp)
 {
-	struct whatchanged_opt wcopt;
-
-	memset(&wcopt, 0, sizeof(wcopt));
-	wcopt.do_diff = 1;
-	init_log_tree_opt(&wcopt.logopt);
-	wcopt.logopt.ignore_merges = 0;
-	wcopt.logopt.combine_merges = 1;
-	wcopt.logopt.dense_combined_merges = 1;
-	wcopt.logopt.diffopt.recursive = 1;
-	return cmd_log_wc(ac, av, ep, &wcopt);
+	struct rev_info rev;
+
+	init_revisions(&rev);
+	rev.abbrev = DEFAULT_ABBREV;
+	rev.no_commit_id = 1;
+	rev.commit_format = CMIT_FMT_DEFAULT;
+	argc = setup_revisions(argc, argv, &rev, "HEAD");
+	return cmd_log_wc(argc, argv, envp, &rev);
 }
 
 static void handle_internal_command(int argc, const char **argv, char **envp)
@@ -389,8 +395,8 @@ static void handle_internal_command(int argc, const char **argv, char **envp)
 		{ "version", cmd_version },
 		{ "help", cmd_help },
 		{ "log", cmd_log },
+		{ "whatchanged", cmd_wc },
 		{ "show", cmd_show },
-		{ "whatchanged", cmd_whatchanged },
 	};
 	int i;
 
diff --git a/http-push.c b/http-push.c
index 19a0f772e7..4a9dcf2bf6 100644
--- a/http-push.c
+++ b/http-push.c
@@ -2498,6 +2498,7 @@ int main(int argc, char **argv)
 			commit_argv[3] = old_sha1_hex;
 			commit_argc++;
 		}
+		init_revisions(&revs);
 		setup_revisions(commit_argc, commit_argv, &revs, NULL);
 		free(new_sha1_hex);
 		if (old_sha1_hex) {
diff --git a/log-tree.c b/log-tree.c
index 17e976a637..04a68e0f57 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -3,57 +3,7 @@
 #include "commit.h"
 #include "log-tree.h"
 
-void init_log_tree_opt(struct log_tree_opt *opt)
-{
-	memset(opt, 0, sizeof *opt);
-	opt->ignore_merges = 1;
-	opt->header_prefix = "";
-	opt->commit_format = CMIT_FMT_RAW;
-	diff_setup(&opt->diffopt);
-}
-
-int log_tree_opt_parse(struct log_tree_opt *opt, const char **av, int ac)
-{
-	const char *arg;
-	int cnt = diff_opt_parse(&opt->diffopt, av, ac);
-	if (0 < cnt)
-		return cnt;
-	arg = *av;
-	if (!strcmp(arg, "-r"))
-		opt->diffopt.recursive = 1;
-	else if (!strcmp(arg, "-t")) {
-		opt->diffopt.recursive = 1;
-		opt->diffopt.tree_in_recursive = 1;
-	}
-	else if (!strcmp(arg, "-m"))
-		opt->ignore_merges = 0;
-	else if (!strcmp(arg, "-c"))
-		opt->combine_merges = 1;
-	else if (!strcmp(arg, "--cc")) {
-		opt->dense_combined_merges = 1;
-		opt->combine_merges = 1;
-	}
-	else if (!strcmp(arg, "-v")) {
-		opt->verbose_header = 1;
-		opt->header_prefix = "diff-tree ";
-	}
-	else if (!strncmp(arg, "--pretty", 8)) {
-		opt->verbose_header = 1;
-		opt->header_prefix = "diff-tree ";
-		opt->commit_format = get_commit_format(arg+8);
-	}
-	else if (!strcmp(arg, "--root"))
-		opt->show_root_diff = 1;
-	else if (!strcmp(arg, "--no-commit-id"))
-		opt->no_commit_id = 1;
-	else if (!strcmp(arg, "--always"))
-		opt->always_show_header = 1;
-	else
-		return 0;
-	return 1;
-}
-
-int log_tree_diff_flush(struct log_tree_opt *opt)
+int log_tree_diff_flush(struct rev_info *opt)
 {
 	diffcore_std(&opt->diffopt);
 	if (diff_queue_is_empty()) {
@@ -73,7 +23,7 @@ int log_tree_diff_flush(struct log_tree_opt *opt)
 	return 1;
 }
 
-static int diff_root_tree(struct log_tree_opt *opt,
+static int diff_root_tree(struct rev_info *opt,
 			  const unsigned char *new, const char *base)
 {
 	int retval;
@@ -93,7 +43,7 @@ static int diff_root_tree(struct log_tree_opt *opt,
 	return retval;
 }
 
-static const char *generate_header(struct log_tree_opt *opt,
+static const char *generate_header(struct rev_info *opt,
 				   const unsigned char *commit_sha1,
 				   const unsigned char *parent_sha1,
 				   const struct commit *commit)
@@ -129,7 +79,7 @@ static const char *generate_header(struct log_tree_opt *opt,
 	return this_header;
 }
 
-static int do_diff_combined(struct log_tree_opt *opt, struct commit *commit)
+static int do_diff_combined(struct rev_info *opt, struct commit *commit)
 {
 	unsigned const char *sha1 = commit->object.sha1;
 
@@ -142,7 +92,7 @@ static int do_diff_combined(struct log_tree_opt *opt, struct commit *commit)
 	return 0;
 }
 
-int log_tree_commit(struct log_tree_opt *opt, struct commit *commit)
+int log_tree_commit(struct rev_info *opt, struct commit *commit)
 {
 	struct commit_list *parents;
 	unsigned const char *sha1 = commit->object.sha1;
@@ -173,70 +123,3 @@ int log_tree_commit(struct log_tree_opt *opt, struct commit *commit)
 	}
 	return 0;
 }
-
-int parse_whatchanged_opt(int ac, const char **av, struct whatchanged_opt *wcopt)
-{
-	struct rev_info *rev = &wcopt->revopt;
-	struct log_tree_opt *opt = &wcopt->logopt;
-	const char **unrecognized = av+1;
-	int left = 1;
-
-	ac = setup_revisions(ac, av, rev, "HEAD");
-	if (!strcmp(av[0], "show"))
-		rev->no_walk = 1;
-	while (1 < ac) {
-		const char *arg = av[1];
-		if (!strncmp(arg, "--pretty", 8)) {
-			opt->commit_format = get_commit_format(arg + 8);
-		}
-		else if (!strcmp(arg, "--no-abbrev")) {
-			wcopt->abbrev = 0;
-		}
-		else if (!strcmp(arg, "--abbrev")) {
-			wcopt->abbrev = DEFAULT_ABBREV;
-		}
-		else if (!strcmp(arg, "--abbrev-commit")) {
-			wcopt->abbrev_commit = 1;
-		}
-		else if (!strncmp(arg, "--abbrev=", 9)) {
-			wcopt->abbrev = strtoul(arg + 9, NULL, 10);
-			if (wcopt->abbrev && wcopt->abbrev < MINIMUM_ABBREV)
-				wcopt->abbrev = MINIMUM_ABBREV;
-			else if (40 < wcopt->abbrev)
-				wcopt->abbrev = 40;
-		}
-		else if (!strcmp(arg, "--full-diff")) {
-			wcopt->do_diff = 1;
-			wcopt->full_diff = 1;
-		}
-		else {
-			int cnt = log_tree_opt_parse(opt, av+1, ac-1);
-			if (0 < cnt) {
-				wcopt->do_diff = 1;
-				av += cnt;
-				ac -= cnt;
-				continue;
-			}
-			*unrecognized++ = arg;
-			left++;
-		}
-		ac--; av++;
-	}
-
-	if (wcopt->do_diff) {
-		opt->diffopt.abbrev = wcopt->abbrev;
-		opt->verbose_header = 0;
-		opt->always_show_header = 0;
-		opt->no_commit_id = 1;
-		if (opt->combine_merges)
-			opt->ignore_merges = 0;
-		if (opt->dense_combined_merges)
-			opt->diffopt.output_format = DIFF_FORMAT_PATCH;
-		if (opt->diffopt.output_format == DIFF_FORMAT_PATCH)
-			opt->diffopt.recursive = 1;
-		if (!wcopt->full_diff && rev->prune_data)
-			diff_tree_setup_paths(rev->prune_data, &opt->diffopt);
-		diff_setup_done(&opt->diffopt);
-	}
-	return left;
-}
diff --git a/log-tree.h b/log-tree.h
index 8d8f6f1458..91a909be73 100644
--- a/log-tree.h
+++ b/log-tree.h
@@ -3,34 +3,9 @@
 
 #include "revision.h"
 
-struct log_tree_opt {
-	struct diff_options diffopt;
-	int show_root_diff;
-	int no_commit_id;
-	int verbose_header;
-	int ignore_merges;
-	int combine_merges;
-	int dense_combined_merges;
-	int always_show_header;
-	const char *header_prefix;
-	const char *header;
-	enum cmit_fmt commit_format;
-};
-
-void init_log_tree_opt(struct log_tree_opt *);
-int log_tree_diff_flush(struct log_tree_opt *);
-int log_tree_commit(struct log_tree_opt *, struct commit *);
-int log_tree_opt_parse(struct log_tree_opt *, const char **, int);
-
-struct whatchanged_opt {
-	struct rev_info revopt;
-	struct log_tree_opt logopt;
-	int abbrev;
-	int abbrev_commit;
-	int do_diff;
-	int full_diff;
-};
-
-int parse_whatchanged_opt(int, const char **, struct whatchanged_opt *);
+void init_log_tree_opt(struct rev_info *);
+int log_tree_diff_flush(struct rev_info *);
+int log_tree_commit(struct rev_info *, struct commit *);
+int log_tree_opt_parse(struct rev_info *, const char **, int);
 
 #endif
diff --git a/rev-list.c b/rev-list.c
index cb67b399fc..33741ebbc4 100644
--- a/rev-list.c
+++ b/rev-list.c
@@ -39,24 +39,20 @@ static const char rev_list_usage[] =
 struct rev_info revs;
 
 static int bisect_list = 0;
-static int verbose_header = 0;
-static int abbrev = DEFAULT_ABBREV;
-static int abbrev_commit = 0;
 static int show_timestamp = 0;
 static int hdr_termination = 0;
-static const char *commit_prefix = "";
-static enum cmit_fmt commit_format = CMIT_FMT_RAW;
 
 static void show_commit(struct commit *commit)
 {
 	if (show_timestamp)
 		printf("%lu ", commit->date);
-	if (commit_prefix[0])
-		fputs(commit_prefix, stdout);
+	if (*revs.header_prefix)
+		fputs(revs.header_prefix, stdout);
 	if (commit->object.flags & BOUNDARY)
 		putchar('-');
-	if (abbrev_commit && abbrev)
-		fputs(find_unique_abbrev(commit->object.sha1, abbrev), stdout);
+	if (revs.abbrev_commit && revs.abbrev)
+		fputs(find_unique_abbrev(commit->object.sha1, revs.abbrev),
+		      stdout);
 	else
 		fputs(sha1_to_hex(commit->object.sha1), stdout);
 	if (revs.parents) {
@@ -78,14 +74,16 @@ static void show_commit(struct commit *commit)
 		     parents = parents->next)
 			parents->item->object.flags &= ~TMP_MARK;
 	}
-	if (commit_format == CMIT_FMT_ONELINE)
+	if (revs.commit_format == CMIT_FMT_ONELINE)
 		putchar(' ');
 	else
 		putchar('\n');
 
-	if (verbose_header) {
+	if (revs.verbose_header) {
 		static char pretty_header[16384];
-		pretty_print_commit(commit_format, commit, ~0, pretty_header, sizeof(pretty_header), abbrev);
+		pretty_print_commit(revs.commit_format, commit, ~0,
+				    pretty_header, sizeof(pretty_header),
+				    revs.abbrev);
 		printf("%s%c", pretty_header, hdr_termination);
 	}
 	fflush(stdout);
@@ -297,58 +295,16 @@ int main(int argc, const char **argv)
 	struct commit_list *list;
 	int i;
 
+	init_revisions(&revs);
+	revs.abbrev = 0;
+	revs.commit_format = CMIT_FMT_UNSPECIFIED;
 	argc = setup_revisions(argc, argv, &revs, NULL);
 
 	for (i = 1 ; i < argc; i++) {
 		const char *arg = argv[i];
 
-		/* accept -<digit>, like traditilnal "head" */
-		if ((*arg == '-') && isdigit(arg[1])) {
-			revs.max_count = atoi(arg + 1);
-			continue;
-		}
-		if (!strcmp(arg, "-n")) {
-			if (++i >= argc)
-				die("-n requires an argument");
-			revs.max_count = atoi(argv[i]);
-			continue;
-		}
-		if (!strncmp(arg,"-n",2)) {
-			revs.max_count = atoi(arg + 2);
-			continue;
-		}
 		if (!strcmp(arg, "--header")) {
-			verbose_header = 1;
-			continue;
-		}
-		if (!strcmp(arg, "--no-abbrev")) {
-			abbrev = 0;
-			continue;
-		}
-		if (!strcmp(arg, "--abbrev")) {
-			abbrev = DEFAULT_ABBREV;
-			continue;
-		}
-		if (!strcmp(arg, "--abbrev-commit")) {
-			abbrev_commit = 1;
-			continue;
-		}
-		if (!strncmp(arg, "--abbrev=", 9)) {
-			abbrev = strtoul(arg + 9, NULL, 10);
-			if (abbrev && abbrev < MINIMUM_ABBREV)
-				abbrev = MINIMUM_ABBREV;
-			else if (40 < abbrev)
-				abbrev = 40;
-			continue;
-		}
-		if (!strncmp(arg, "--pretty", 8)) {
-			commit_format = get_commit_format(arg+8);
-			verbose_header = 1;
-			hdr_termination = '\n';
-			if (commit_format == CMIT_FMT_ONELINE)
-				commit_prefix = "";
-			else
-				commit_prefix = "commit ";
+			revs.verbose_header = 1;
 			continue;
 		}
 		if (!strcmp(arg, "--timestamp")) {
@@ -362,14 +318,24 @@ int main(int argc, const char **argv)
 		usage(rev_list_usage);
 
 	}
+	if (revs.commit_format != CMIT_FMT_UNSPECIFIED) {
+		/* The command line has a --pretty  */
+		hdr_termination = '\n';
+		if (revs.commit_format == CMIT_FMT_ONELINE)
+			revs.header_prefix = "";
+		else
+			revs.header_prefix = "commit ";
+	}
 
 	list = revs.commits;
 
-	if (!list &&
-	    (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) && !revs.pending_objects))
+	if ((!list &&
+	     (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) &&
+	      !revs.pending_objects)) ||
+	    revs.diff)
 		usage(rev_list_usage);
 
-	save_commit_buffer = verbose_header;
+	save_commit_buffer = revs.verbose_header;
 	track_object_refs = 0;
 	if (bisect_list)
 		revs.limited = 1;
diff --git a/revision.c b/revision.c
index 0c3c392fde..f8fb028855 100644
--- a/revision.c
+++ b/revision.c
@@ -116,21 +116,27 @@ static void add_pending_object(struct rev_info *revs, struct object *obj, const
 	add_object(obj, &revs->pending_objects, NULL, name);
 }
 
-static struct commit *get_commit_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
+static struct object *get_reference(struct rev_info *revs, const char *name, const unsigned char *sha1, unsigned int flags)
 {
 	struct object *object;
 
 	object = parse_object(sha1);
 	if (!object)
 		die("bad object %s", name);
+	object->flags |= flags;
+	return object;
+}
+
+static struct commit *handle_commit(struct rev_info *revs, struct object *object, const char *name)
+{
+	unsigned long flags = object->flags;
 
 	/*
 	 * Tag object? Look what it points to..
 	 */
 	while (object->type == tag_type) {
 		struct tag *tag = (struct tag *) object;
-		object->flags |= flags;
-		if (revs->tag_objects && !(object->flags & UNINTERESTING))
+		if (revs->tag_objects && !(flags & UNINTERESTING))
 			add_pending_object(revs, object, tag->tag);
 		object = parse_object(tag->tagged->sha1);
 		if (!object)
@@ -143,7 +149,6 @@ static struct commit *get_commit_reference(struct rev_info *revs, const char *na
 	 */
 	if (object->type == commit_type) {
 		struct commit *commit = (struct commit *)object;
-		object->flags |= flags;
 		if (parse_commit(commit) < 0)
 			die("unable to parse commit %s", name);
 		if (flags & UNINTERESTING) {
@@ -241,7 +246,7 @@ int rev_compare_tree(struct rev_info *revs, struct tree *t1, struct tree *t2)
 		return REV_TREE_DIFFERENT;
 	tree_difference = REV_TREE_SAME;
 	if (diff_tree_sha1(t1->object.sha1, t2->object.sha1, "",
-			   &revs->diffopt) < 0)
+			   &revs->pruning) < 0)
 		return REV_TREE_DIFFERENT;
 	return tree_difference;
 }
@@ -264,7 +269,7 @@ int rev_same_tree_as_empty(struct rev_info *revs, struct tree *t1)
 	empty.size = 0;
 
 	tree_difference = 0;
-	retval = diff_tree(&empty, &real, "", &revs->diffopt);
+	retval = diff_tree(&empty, &real, "", &revs->pruning);
 	free(tree);
 
 	return retval >= 0 && !tree_difference;
@@ -454,21 +459,13 @@ static void limit_list(struct rev_info *revs)
 	revs->commits = newlist;
 }
 
-static void add_one_commit(struct commit *commit, struct rev_info *revs)
-{
-	if (!commit || (commit->object.flags & SEEN))
-		return;
-	commit->object.flags |= SEEN;
-	commit_list_insert(commit, &revs->commits);
-}
-
 static int all_flags;
 static struct rev_info *all_revs;
 
 static int handle_one_ref(const char *path, const unsigned char *sha1)
 {
-	struct commit *commit = get_commit_reference(all_revs, path, sha1, all_flags);
-	add_one_commit(commit, all_revs);
+	struct object *object = get_reference(all_revs, path, sha1, all_flags);
+	add_pending_object(all_revs, object, "");
 	return 0;
 }
 
@@ -482,9 +479,12 @@ static void handle_all(struct rev_info *revs, unsigned flags)
 void init_revisions(struct rev_info *revs)
 {
 	memset(revs, 0, sizeof(*revs));
-	revs->diffopt.recursive = 1;
-	revs->diffopt.add_remove = file_add_remove;
-	revs->diffopt.change = file_change;
+
+	revs->abbrev = DEFAULT_ABBREV;
+	revs->ignore_merges = 1;
+	revs->pruning.recursive = 1;
+	revs->pruning.add_remove = file_add_remove;
+	revs->pruning.change = file_change;
 	revs->lifo = 1;
 	revs->dense = 1;
 	revs->prefix = setup_git_directory();
@@ -497,6 +497,11 @@ void init_revisions(struct rev_info *revs)
 
 	revs->topo_setter = topo_sort_default_setter;
 	revs->topo_getter = topo_sort_default_getter;
+
+	revs->header_prefix = "";
+	revs->commit_format = CMIT_FMT_DEFAULT;
+
+	diff_setup(&revs->diffopt);
 }
 
 /*
@@ -512,8 +517,6 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 	const char **unrecognized = argv + 1;
 	int left = 1;
 
-	init_revisions(revs);
-
 	/* First, search for "--" */
 	seen_dashdash = 0;
 	for (i = 1; i < argc; i++) {
@@ -529,13 +532,14 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 
 	flags = 0;
 	for (i = 1; i < argc; i++) {
-		struct commit *commit;
+		struct object *object;
 		const char *arg = argv[i];
 		unsigned char sha1[20];
 		char *dotdot;
 		int local_flags;
 
 		if (*arg == '-') {
+			int opts;
 			if (!strncmp(arg, "--max-count=", 12)) {
 				revs->max_count = atoi(arg + 12);
 				continue;
@@ -643,6 +647,78 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 				revs->unpacked = 1;
 				continue;
 			}
+			if (!strcmp(arg, "-r")) {
+				revs->diff = 1;
+				revs->diffopt.recursive = 1;
+				continue;
+			}
+			if (!strcmp(arg, "-t")) {
+				revs->diff = 1;
+				revs->diffopt.recursive = 1;
+				revs->diffopt.tree_in_recursive = 1;
+				continue;
+			}
+			if (!strcmp(arg, "-m")) {
+				revs->ignore_merges = 0;
+				continue;
+			}
+			if (!strcmp(arg, "-c")) {
+				revs->diff = 1;
+				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;
+				revs->header_prefix = "diff-tree ";
+				continue;
+			}
+			if (!strncmp(arg, "--pretty", 8)) {
+				revs->verbose_header = 1;
+				revs->header_prefix = "diff-tree ";
+				revs->commit_format = get_commit_format(arg+8);
+				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 (!strcmp(arg, "--abbrev-commit")) {
+				revs->abbrev_commit = 1;
+				continue;
+			}
+			if (!strcmp(arg, "--full-diff")) {
+				revs->diff = 1;
+				revs->full_diff = 1;
+				continue;
+			}
+			opts = diff_opt_parse(&revs->diffopt, argv+i, argc-i);
+			if (opts > 0) {
+				revs->diff = 1;
+				i += opts - 1;
+				continue;
+			}
 			*unrecognized++ = arg;
 			left++;
 			continue;
@@ -659,15 +735,15 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 				this = "HEAD";
 			if (!get_sha1(this, from_sha1) &&
 			    !get_sha1(next, sha1)) {
-				struct commit *exclude;
-				struct commit *include;
+				struct object *exclude;
+				struct object *include;
 
-				exclude = get_commit_reference(revs, this, from_sha1, flags ^ UNINTERESTING);
-				include = get_commit_reference(revs, next, sha1, flags);
+				exclude = get_reference(revs, this, from_sha1, flags ^ UNINTERESTING);
+				include = get_reference(revs, next, sha1, flags);
 				if (!exclude || !include)
 					die("Invalid revision range %s..%s", arg, next);
-				add_one_commit(exclude, revs);
-				add_one_commit(include, revs);
+				add_pending_object(revs, exclude, this);
+				add_pending_object(revs, include, next);
 				continue;
 			}
 			*dotdot = '.';
@@ -692,34 +768,59 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 			revs->prune_data = get_pathspec(revs->prefix, argv + i);
 			break;
 		}
-		commit = get_commit_reference(revs, arg, sha1, flags ^ local_flags);
-		add_one_commit(commit, revs);
+		object = get_reference(revs, arg, sha1, flags ^ local_flags);
+		add_pending_object(revs, object, arg);
 	}
-	if (def && !revs->commits) {
+	if (def && !revs->pending_objects) {
 		unsigned char sha1[20];
-		struct commit *commit;
+		struct object *object;
 		if (get_sha1(def, sha1) < 0)
 			die("bad default revision '%s'", def);
-		commit = get_commit_reference(revs, def, sha1, 0);
-		add_one_commit(commit, revs);
+		object = get_reference(revs, def, sha1, 0);
+		add_pending_object(revs, object, def);
 	}
 
 	if (revs->topo_order || revs->unpacked)
 		revs->limited = 1;
 
 	if (revs->prune_data) {
-		diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
+		diff_tree_setup_paths(revs->prune_data, &revs->pruning);
 		revs->prune_fn = try_to_simplify_commit;
+		if (!revs->full_diff)
+			diff_tree_setup_paths(revs->prune_data, &revs->diffopt);
+	}
+	if (revs->combine_merges) {
+		revs->ignore_merges = 0;
+		if (revs->dense_combined_merges)
+			revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 	}
+	if (revs->diffopt.output_format == DIFF_FORMAT_PATCH)
+		revs->diffopt.recursive = 1;
+	revs->diffopt.abbrev = revs->abbrev;
+	diff_setup_done(&revs->diffopt);
 
 	return left;
 }
 
 void prepare_revision_walk(struct rev_info *revs)
 {
+	struct object_list *list;
+
+	list = revs->pending_objects;
+	revs->pending_objects = NULL;
+	while (list) {
+		struct commit *commit = handle_commit(revs, list->item, list->name);
+		if (commit) {
+			if (!(commit->object.flags & SEEN)) {
+				commit->object.flags |= SEEN;
+				insert_by_date(commit, &revs->commits);
+			}
+		}
+		list = list->next;
+	}
+
 	if (revs->no_walk)
 		return;
-	sort_by_date(&revs->commits);
 	if (revs->limited)
 		limit_list(revs);
 	if (revs->topo_order)
diff --git a/revision.h b/revision.h
index ff2a13ea87..7b854866b2 100644
--- a/revision.h
+++ b/revision.h
@@ -39,13 +39,32 @@ struct rev_info {
 			boundary:1,
 			parents:1;
 
+	/* Diff flags */
+	unsigned int	diff:1,
+			full_diff:1,
+			show_root_diff:1,
+			no_commit_id:1,
+			verbose_header:1,
+			ignore_merges:1,
+			combine_merges:1,
+			dense_combined_merges:1,
+			always_show_header:1;
+
+	/* Format info */
+	unsigned int	abbrev_commit:1;
+	unsigned int	abbrev;
+	enum cmit_fmt	commit_format;
+	const char	*header_prefix;
+	const char	*header;
+
 	/* special limits */
 	int max_count;
 	unsigned long max_age;
 	unsigned long min_age;
 
-	/* paths limiting */
+	/* diff info for patches and for paths limiting */
 	struct diff_options diffopt;
+	struct diff_options pruning;
 
 	topo_sort_set_fn_t topo_setter;
 	topo_sort_get_fn_t topo_getter;