[RFC] describe: add option --dirty

[Yasushi SHOJI <yashi@atmark-techno.com>]

when --dirty is given, git describe will check the working tree and
append "-dirty" to describe string if the tree is dirty.
---
I'm not sure this is good idea or the current way (using diff-index in
shell script) is more prefered.

one thing I found out is that we s/-/./g the out put of describe
before we append "-dirty".  this patch doesn't take care that. so with
this patch what we get is either

	v1.5.3-rc2-840-g1c0e2-dirty, or
	v1.5.3.rc2.840.g1c0e2.dirty

if we don't put more complecated sed command in GIT-VERSION-GEN.

anyway, comments welcome.

ps. another thing I don't like about this patch is that it changed to
pass prefix down to describe() as the last argument because I was lazy
to call cmd_diff_index() in describe().  if there is better way to do
it, please let me know.


 Documentation/git-describe.txt |    5 ++++-
 builtin-describe.c             |   29 ++++++++++++++++++++++-------
 2 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/Documentation/git-describe.txt b/Documentation/git-describe.txt
index f0bcb61..627c4d5 100644
--- a/Documentation/git-describe.txt
+++ b/Documentation/git-describe.txt
@@ -9,7 +9,7 @@ git-describe - Show the most recent tag that is reachable from a commit
 SYNOPSIS
 --------
 'git-describe' [--all] [--tags] [--contains] [--abbrev=<n>]
-               [--candidates=<n>] [--debug]
+               [--candidates=<n>] [--debug] [--dirty]
                <committish>...
 
 DESCRIPTION
@@ -53,6 +53,9 @@ OPTIONS
 	being employed to standard error.  The tag name will still
 	be printed to standard out.
 
+--dirty::
+	Append "-dirty" to describe string if working tree is dirty.
+
 EXAMPLES
 --------
 
diff --git a/builtin-describe.c b/builtin-describe.c
index e94f867..bebc16b 100644
--- a/builtin-describe.c
+++ b/builtin-describe.c
@@ -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++;
 		}
 
-- 
1.5.3.rc2.4.g726f9