describe: add option --dirty

index e94f867..bebc16b 100644
@@ -9,11 +9,12 @@
 #define MAX_TAGS	(FLAG_BITS - 1)
 
 static const char describe_usage[] =
-"git-describe [--all] [--tags] [--contains] [--abbrev=<n>] [--candidates] [--debug] <committish>*";
+"git-describe [--all] [--tags] [--contains] [--abbrev=<n>] [--candidates] [--debug] [--dirty] <committish>*";
 
 static int debug;	/* Display lots of verbose info */
 static int all;	/* Default to annotated tags only */
 static int tags;	/* But allow any tags if --tags is specified */
+static int check_dirty;	/* Append "-dirty" to describe string if working tree is dirty */
 static int abbrev = DEFAULT_ABBREV;
 static int max_candidates = 10;
 

@@ -125,7 +126,7 @@ static unsigned long finish_depth_computation(
 	return seen_commits;
 }
 
-static void describe(const char *arg, int last_one)
+static void describe(const char *arg, int last_one, const char *prefix)
 {
 	unsigned char sha1[20];
 	struct commit *cmit, *gave_up_on = NULL;

@@ -135,6 +136,7 @@ static void describe(const char *arg, int last_one)
 	struct possible_tag all_matches[MAX_TAGS];
 	unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 	unsigned long seen_commits = 0;
+	char *dirty_string = "";
 
 	if (get_sha1(arg, sha1))
 		die("Not a valid object name %s", arg);

@@ -229,12 +231,23 @@ static void describe(const char *arg, int last_one)
 				sha1_to_hex(gave_up_on->object.sha1));
 		}
 	}
+	if (check_dirty) {
+		const char **args = xmalloc(5 * sizeof(char*));
+		args[0] = "diff-index";
+		args[1] = "--quiet";
+		args[2] = "--name-only";
+		args[3] = "HEAD";
+		args[4] = NULL;
+		if (cmd_diff_index(4, args, prefix))
+			dirty_string = "-dirty";
+	}
 	if (abbrev == 0)
-		printf("%s\n", all_matches[0].name->path );
+		printf("%s%s\n", all_matches[0].name->path, dirty_string);
 	else
-		printf("%s-%d-g%s\n", all_matches[0].name->path,
+		printf("%s-%d-g%s%s\n", all_matches[0].name->path,
 		       all_matches[0].depth,
-		       find_unique_abbrev(cmit->object.sha1, abbrev));
+		       find_unique_abbrev(cmit->object.sha1, abbrev),
+		       dirty_string);
 
 	if (!last_one)
 		clear_commit_marks(cmit, -1);

@@ -250,6 +263,8 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 
 		if (*arg != '-')
 			break;
+		else if (!strcmp(arg, "--dirty"))
+			check_dirty = 1;
 		else if (!strcmp(arg, "--contains"))
 			contains = 1;
 		else if (!strcmp(arg, "--debug"))

@@ -290,10 +305,10 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 	}
 
 	if (argc <= i)
-		describe("HEAD", 1);
+		describe("HEAD", 1, prefix);
 	else
 		while (i < argc) {
-			describe(argv[i], (i == argc - 1));
+			describe(argv[i], (i == argc - 1), prefix);
 			i++;
 		}
 

index e94f867..1c58480 100644
@@ -9,11 +9,12 @@
 #define MAX_TAGS	(FLAG_BITS - 1)
 
 static const char describe_usage[] =
-"git-describe [--all] [--tags] [--contains] [--abbrev=<n>] [--candidates] [--debug] <committish>*";
+"git-describe [--all] [--tags] [--contains] [--abbrev=<n>] [--candidates] [--debug] --working-tree | <committish>*";
 
 static int debug;	/* Display lots of verbose info */
 static int all;	/* Default to annotated tags only */
 static int tags;	/* But allow any tags if --tags is specified */
+static int working_tree;/* describe the working tree instead of committish */
 static int abbrev = DEFAULT_ABBREV;
 static int max_candidates = 10;
 

@@ -125,7 +126,7 @@ static unsigned long finish_depth_computation(
 	return seen_commits;
 }
 
-static void describe(const char *arg, int last_one)
+static void describe(const char *arg, int last_one, int dirty)
 {
 	unsigned char sha1[20];
 	struct commit *cmit, *gave_up_on = NULL;

@@ -135,6 +136,7 @@ static void describe(const char *arg, int last_one)
 	struct possible_tag all_matches[MAX_TAGS];
 	unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 	unsigned long seen_commits = 0;
+	char *dirty_string = dirty ? "-dirty" : "";
 
 	if (get_sha1(arg, sha1))
 		die("Not a valid object name %s", arg);

@@ -230,11 +232,12 @@ static void describe(const char *arg, int last_one)
 		}
 	}
 	if (abbrev == 0)
-		printf("%s\n", all_matches[0].name->path );
+		printf("%s%s\n", all_matches[0].name->path, dirty_string);
 	else
-		printf("%s-%d-g%s\n", all_matches[0].name->path,
+		printf("%s-%d-g%s%s\n", all_matches[0].name->path,
 		       all_matches[0].depth,
-		       find_unique_abbrev(cmit->object.sha1, abbrev));
+		       find_unique_abbrev(cmit->object.sha1, abbrev),
+		       dirty_string);
 
 	if (!last_one)
 		clear_commit_marks(cmit, -1);

@@ -244,12 +247,15 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 {
 	int i;
 	int contains = 0;
+	int dirty = 0;
 
 	for (i = 1; i < argc; i++) {
 		const char *arg = argv[i];
 
 		if (*arg != '-')
 			break;
+		else if (!strcmp(arg, "--working-tree"))
+			working_tree = 1;
 		else if (!strcmp(arg, "--contains"))
 			contains = 1;
 		else if (!strcmp(arg, "--debug"))

@@ -276,6 +282,24 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 
 	save_commit_buffer = 0;
 
+	if (working_tree) {
+		const char **args;
+
+		if (!is_inside_work_tree() || is_inside_git_dir())
+			die("%s with --working-tree must be run in a working tree", argv[0]);
+		if (argc > i)
+			die("--working-tree doesn't take any committish\n");
+
+		args = xmalloc(5 * sizeof(char*));
+		args[0] = "diff-index";
+		args[1] = "--quiet";
+		args[2] = "--name-only";
+		args[3] = "HEAD";
+		args[4] = NULL;
+		if (cmd_diff_index(4, args, prefix))
+			dirty = 1;
+	}
+
 	if (contains) {
 		const char **args = xmalloc((4 + argc - i) * sizeof(char*));
 		args[0] = "name-rev";

@@ -290,10 +314,10 @@ int cmd_describe(int argc, const char **argv, const char *prefix)
 	}
 
 	if (argc <= i)
-		describe("HEAD", 1);
+		describe("HEAD", 1, dirty);
 	else
 		while (i < argc) {
-			describe(argv[i], (i == argc - 1));
+			describe(argv[i], (i == argc - 1), dirty);
 			i++;
 		}