[RFC/PATCH] status: Add a new NUL separated output format

[Julian Phillips <julian@quantumfyre.co.uk>]

Add a new output format option to git-status that is a more extreme
form of the -z output that places a NUL between all parts of the
record, and always has three entries per record, even when only two
are relevant.  This make the parsing of --porcelain output much
simpler for the consumer.

Signed-off-by: Julian Phillips <julian@quantumfyre.co.uk>
---

On Sat, 10 Apr 2010, Julian Phillips wrote:

> Not true.  If the second form was used, then you _can_ split on \0.  It
> will tokenise the data for you, and then you consume ether two or three
> tokens depending on the status flags.  So it would make the parsing
> simpler.  But to make it even easier, how about adding a -Z that makes the
> output format "XY\0file1\0[file2]\0" (i.e. always three tokens per record,
> with the third token being empty if there is no second filename)?  Though
> if future expandability was wanted you could end each record with \0\0 and
> then parsing would be a two stages of split on \0\0 for records and then
> split on \0 for entries?  The is already precedence for the -z option to
> change the output format, so a second similar switch should be ok?  Then
> the updated documentation could recommend --porcelain -Z for new users
> without affecting old ones.

Something like this for the first variant (fixed three entries per record)
perhaps ... (though a proper patch would probably want some tests too)

 builtin/commit.c |    6 ++++--
 wt-status.c      |   19 ++++++++++++++-----
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/builtin/commit.c b/builtin/commit.c
index c5ab683..acbcefc 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1025,8 +1025,10 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 		OPT_SET_INT(0, "porcelain", &status_format,
 			    "show porcelain output format",
 			    STATUS_FORMAT_PORCELAIN),
-		OPT_BOOLEAN('z', "null", &null_termination,
-			    "terminate entries with NUL"),
+		OPT_SET_INT('z', "null", &null_termination,
+			    "terminate entries with NUL", 1),
+		OPT_SET_INT('Z', "intense-null", &null_termination,
+			    "use NUL for all seperators, including absent values", 2),
 		{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg,
 		  "mode",
 		  "show untracked files, optional modes: all, normal, no. (Default: all)",
diff --git a/wt-status.c b/wt-status.c
index 8ca59a2..9f23ec6 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -663,7 +663,9 @@ static void wt_shortstatus_unmerged(int null_termination, struct string_list_ite
 	case 7: how = "UU"; break; /* both modified */
 	}
 	color_fprintf(s->fp, color(WT_STATUS_UNMERGED, s), "%s", how);
-	if (null_termination) {
+	if (null_termination == 2) {
+		fprintf(stdout, "%c%s%c%c", 0, it->string, 0, 0);
+	} else if (null_termination) {
 		fprintf(stdout, " %s%c", it->string, 0);
 	} else {
 		struct strbuf onebuf = STRBUF_INIT;
@@ -687,14 +689,19 @@ static void wt_shortstatus_status(int null_termination, struct string_list_item
 		color_fprintf(s->fp, color(WT_STATUS_CHANGED, s), "%c", d->worktree_status);
 	else
 		putchar(' ');
-	putchar(' ');
-	if (null_termination) {
-		fprintf(stdout, "%s%c", it->string, 0);
+	if (null_termination == 2) {
+		char *file2 = "";
+		if (d->head_path)
+			file2 = d->head_path;
+		fprintf(stdout, "%c%s%c%s%c", 0, it->string, 0, file2, 0);
+	} else if (null_termination) {
+		fprintf(stdout, " %s%c", it->string, 0);
 		if (d->head_path)
 			fprintf(stdout, "%s%c", d->head_path, 0);
 	} else {
 		struct strbuf onebuf = STRBUF_INIT;
 		const char *one;
+		putchar(' ');
 		if (d->head_path) {
 			one = quote_path(d->head_path, -1, &onebuf, s->prefix);
 			printf("%s -> ", one);
@@ -709,7 +716,9 @@ static void wt_shortstatus_status(int null_termination, struct string_list_item
 static void wt_shortstatus_untracked(int null_termination, struct string_list_item *it,
 			    struct wt_status *s)
 {
-	if (null_termination) {
+	if (null_termination == 2) {
+		fprintf(stdout, "??%c%s%c%c", 0, it->string, 0, 0);
+	} else if (null_termination) {
 		fprintf(stdout, "?? %s%c", it->string, 0);
 	} else {
 		struct strbuf onebuf = STRBUF_INIT;
-- 
1.7.0.4