git stat: the beginning of "status that is not a dry-run of commit"

Tentatively add "git stat" as a new command.

This is not "preview of commit with the same arguments"; the path parameters
are not paths to be added to the pristine index (aka "--only" option), but
are taken as pathspecs to limit the output.  Later in 1.7.0 release, it will
take over "git status".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Makefile b/Makefile
index daf4296..39dd334 100644
--- a/Makefile
+++ b/Makefile
@@ -378,6 +378,7 @@
 BUILT_INS += git-merge-subtree$X
 BUILT_INS += git-peek-remote$X
 BUILT_INS += git-repo-config$X
+BUILT_INS += git-stat$X
 BUILT_INS += git-show$X
 BUILT_INS += git-stage$X
 BUILT_INS += git-status$X
diff --git a/builtin-commit.c b/builtin-commit.c
index 200ffda..5e23ef1 100644
--- a/builtin-commit.c
+++ b/builtin-commit.c
@@ -24,6 +24,7 @@
 #include "string-list.h"
 #include "rerere.h"
 #include "unpack-trees.h"
+#include "quote.h"
 
 static const char * const builtin_commit_usage[] = {
 	"git commit [options] [--] <filepattern>...",
@@ -35,6 +36,11 @@
 	NULL
 };
 
+static const char * const builtin_stat_usage[] = {
+	"git stat [options]",
+	NULL
+};
+
 static unsigned char head_sha1[20], merge_head_sha1[20];
 static char *use_message_buffer;
 static const char commit_editmsg[] = "COMMIT_EDITMSG";
@@ -346,6 +352,8 @@
 static int run_status(FILE *fp, const char *index_file, const char *prefix, int nowarn,
 		      struct wt_status *s)
 {
+	unsigned char sha1[20];
+
 	if (s->relative_paths)
 		s->prefix = prefix;
 
@@ -357,7 +365,9 @@
 	s->index_file = index_file;
 	s->fp = fp;
 	s->nowarn = nowarn;
+	s->is_initial = get_sha1(s->reference, sha1) ? 1 : 0;
 
+	wt_status_collect(s);
 	wt_status_print(s);
 
 	return s->commitable;
@@ -691,6 +701,21 @@
 	die("No existing author found with '%s'", name);
 }
 
+
+static void handle_untracked_files_arg(struct wt_status *s)
+{
+	if (!untracked_files_arg)
+		; /* default already initialized */
+	else if (!strcmp(untracked_files_arg, "no"))
+		s->show_untracked_files = SHOW_NO_UNTRACKED_FILES;
+	else if (!strcmp(untracked_files_arg, "normal"))
+		s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
+	else if (!strcmp(untracked_files_arg, "all"))
+		s->show_untracked_files = SHOW_ALL_UNTRACKED_FILES;
+	else
+		die("Invalid untracked files mode '%s'", untracked_files_arg);
+}
+
 static int parse_and_validate_options(int argc, const char *argv[],
 				      const char * const usage[],
 				      const char *prefix,
@@ -794,16 +819,7 @@
 	else
 		die("Invalid cleanup mode %s", cleanup_arg);
 
-	if (!untracked_files_arg)
-		; /* default already initialized */
-	else if (!strcmp(untracked_files_arg, "no"))
-		s->show_untracked_files = SHOW_NO_UNTRACKED_FILES;
-	else if (!strcmp(untracked_files_arg, "normal"))
-		s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
-	else if (!strcmp(untracked_files_arg, "all"))
-		s->show_untracked_files = SHOW_ALL_UNTRACKED_FILES;
-	else
-		die("Invalid untracked files mode '%s'", untracked_files_arg);
+	handle_untracked_files_arg(s);
 
 	if (all && argc > 0)
 		die("Paths with -a does not make sense.");
@@ -886,6 +902,45 @@
 	return git_diff_ui_config(k, v, NULL);
 }
 
+int cmd_stat(int argc, const char **argv, const char *prefix)
+{
+	struct wt_status s;
+	unsigned char sha1[20];
+	static struct option builtin_stat_options[] = {
+		OPT__VERBOSE(&verbose),
+		{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg,
+		  "mode",
+		  "show untracked files, optional modes: all, normal, no. (Default: all)",
+		  PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
+		OPT_END(),
+	};
+
+	wt_status_prepare(&s);
+	git_config(git_status_config, &s);
+	argc = parse_options(argc, argv, prefix,
+			     builtin_stat_options,
+			     builtin_stat_usage, 0);
+	handle_untracked_files_arg(&s);
+
+	if (*argv)
+		s.pathspec = get_pathspec(prefix, argv);
+
+	read_cache();
+	refresh_cache(REFRESH_QUIET|REFRESH_UNMERGED);
+	s.is_initial = get_sha1(s.reference, sha1) ? 1 : 0;
+	wt_status_collect(&s);
+
+	s.verbose = verbose;
+	if (s.relative_paths)
+		s.prefix = prefix;
+	if (s.use_color == -1)
+		s.use_color = git_use_color_default;
+	if (diff_use_color_default == -1)
+		diff_use_color_default = git_use_color_default;
+	wt_status_print(&s);
+	return 0;
+}
+
 int cmd_status(int argc, const char **argv, const char *prefix)
 {
 	struct wt_status s;
diff --git a/builtin.h b/builtin.h
index 20427d2..eeaf0b6 100644
--- a/builtin.h
+++ b/builtin.h
@@ -95,6 +95,7 @@
 extern int cmd_shortlog(int argc, const char **argv, const char *prefix);
 extern int cmd_show(int argc, const char **argv, const char *prefix);
 extern int cmd_show_branch(int argc, const char **argv, const char *prefix);
+extern int cmd_stat(int argc, const char **argv, const char *prefix);
 extern int cmd_status(int argc, const char **argv, const char *prefix);
 extern int cmd_stripspace(int argc, const char **argv, const char *prefix);
 extern int cmd_symbolic_ref(int argc, const char **argv, const char *prefix);
diff --git a/git.c b/git.c
index 807d875..de7fcf6 100644
--- a/git.c
+++ b/git.c
@@ -350,6 +350,7 @@
 		{ "shortlog", cmd_shortlog, USE_PAGER },
 		{ "show-branch", cmd_show_branch, RUN_SETUP },
 		{ "show", cmd_show, RUN_SETUP | USE_PAGER },
+		{ "stat", cmd_stat, RUN_SETUP | NEED_WORK_TREE },
 		{ "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 		{ "stripspace", cmd_stripspace },
 		{ "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
diff --git a/wt-status.c b/wt-status.c
index 63598ce..249227c 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -269,6 +269,7 @@
 	rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 	rev.diffopt.format_callback = wt_status_collect_changed_cb;
 	rev.diffopt.format_callback_data = s;
+	rev.prune_data = s->pathspec;
 	run_diff_files(&rev, 0);
 }
 
@@ -285,6 +286,7 @@
 	rev.diffopt.detect_rename = 1;
 	rev.diffopt.rename_limit = 200;
 	rev.diffopt.break_opt = 0;
+	rev.prune_data = s->pathspec;
 	run_diff_index(&rev, 1);
 }
 
@@ -297,6 +299,8 @@
 		struct wt_status_change_data *d;
 		struct cache_entry *ce = active_cache[i];
 
+		if (!ce_path_match(ce, s->pathspec))
+			continue;
 		it = string_list_insert(ce->name, &s->change);
 		d = it->util;
 		if (!d) {
@@ -330,6 +334,8 @@
 		struct dir_entry *ent = dir.entries[i];
 		if (!cache_name_is_other(ent->name, ent->len))
 			continue;
+		if (!match_pathspec(s->pathspec, ent->name, ent->len, 0, NULL))
+			continue;
 		s->workdir_untracked = 1;
 		string_list_insert(ent->name, &s->untracked);
 	}
@@ -533,10 +539,8 @@
 
 void wt_status_print(struct wt_status *s)
 {
-	unsigned char sha1[20];
 	const char *branch_color = color(WT_STATUS_HEADER, s);
 
-	s->is_initial = get_sha1(s->reference, sha1) ? 1 : 0;
 	if (s->branch) {
 		const char *on_what = "On branch ";
 		const char *branch_name = s->branch;
@@ -553,8 +557,6 @@
 			wt_status_print_tracking(s);
 	}
 
-	wt_status_collect(s);
-
 	if (s->is_initial) {
 		color_fprintf_ln(s->fp, color(WT_STATUS_HEADER, s), "#");
 		color_fprintf_ln(s->fp, color(WT_STATUS_HEADER, s), "# Initial commit");
diff --git a/wt-status.h b/wt-status.h
index a0e7517..09fd9f1 100644
--- a/wt-status.h
+++ b/wt-status.h
@@ -31,6 +31,7 @@
 	int is_initial;
 	char *branch;
 	const char *reference;
+	const char **pathspec;
 	int verbose;
 	int amend;
 	int nowarn;