notes: implement 'git notes copy --stdin'

This implements a mass-copy command that takes a sequence of lines in
the format

  <from-sha1> SP <to-sha1> [ SP <rest> ] LF

on stdin, and copies each <from-sha1>'s notes to the <to-sha1>.  The
<rest> is ignored.  The intent, of course, is that this can read the
same input that the 'post-rewrite' hook gets.

The copy_note() function is exposed for everyone's and in particular
the next commit's use.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Acked-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 55 insertions, 1 deletions

diff --git a/builtin-notes.c b/builtin-notes.c
index 123ecad830..daeb14e1d9 100644
--- a/builtin-notes.c
+++ b/builtin-notes.c
@@ -278,6 +278,46 @@ int commit_notes(struct notes_tree *t, const char *msg)
 	return 0;
 }
 
+int notes_copy_from_stdin(int force)
+{
+	struct strbuf buf = STRBUF_INIT;
+	struct notes_tree *t;
+	int ret = 0;
+
+	init_notes(NULL, NULL, NULL, 0);
+	t = &default_notes_tree;
+
+	while (strbuf_getline(&buf, stdin, '\n') != EOF) {
+		unsigned char from_obj[20], to_obj[20];
+		struct strbuf **split;
+		int err;
+
+		split = strbuf_split(&buf, ' ');
+		if (!split[0] || !split[1])
+			die("Malformed input line: '%s'.", buf.buf);
+		strbuf_rtrim(split[0]);
+		strbuf_rtrim(split[1]);
+		if (get_sha1(split[0]->buf, from_obj))
+			die("Failed to resolve '%s' as a valid ref.", split[0]->buf);
+		if (get_sha1(split[1]->buf, to_obj))
+			die("Failed to resolve '%s' as a valid ref.", split[1]->buf);
+
+		err = copy_note(t, from_obj, to_obj, force, combine_notes_overwrite);
+
+		if (err) {
+			error("Failed to copy notes from '%s' to '%s'",
+			      split[0]->buf, split[1]->buf);
+			ret = 1;
+		}
+
+		strbuf_list_free(split);
+	}
+
+	commit_notes(t, "Notes added by 'git notes copy'");
+	free_notes(t);
+	return ret;
+}
+
 int cmd_notes(int argc, const char **argv, const char *prefix)
 {
 	struct notes_tree *t;
@@ -287,7 +327,7 @@ int cmd_notes(int argc, const char **argv, const char *prefix)
 	char logmsg[100];
 
 	int list = 0, add = 0, copy = 0, append = 0, edit = 0, show = 0,
-	    remove = 0, prune = 0, force = 0;
+	    remove = 0, prune = 0, force = 0, from_stdin = 0;
 	int given_object = 0, i = 1, retval = 0;
 	struct msg_arg msg = { 0, 0, STRBUF_INIT };
 	struct option options[] = {
@@ -301,6 +341,7 @@ int cmd_notes(int argc, const char **argv, const char *prefix)
 		OPT_CALLBACK('C', "reuse-message", &msg, "OBJECT",
 			   "reuse specified note object", parse_reuse_arg),
 		OPT_BOOLEAN('f', "force", &force, "replace existing notes"),
+		OPT_BOOLEAN(0, "stdin", &from_stdin, "read objects from stdin"),
 		OPT_END()
 	};
 
@@ -349,8 +390,21 @@ int cmd_notes(int argc, const char **argv, const char *prefix)
 		usage_with_options(git_notes_usage, options);
 	}
 
+	if (!copy && from_stdin) {
+		error("cannot use --stdin with %s subcommand.", argv[0]);
+		usage_with_options(git_notes_usage, options);
+	}
+
 	if (copy) {
 		const char *from_ref;
+		if (from_stdin) {
+			if (argc > 1) {
+				error("too many parameters");
+				usage_with_options(git_notes_usage, options);
+			} else {
+				return notes_copy_from_stdin(force);
+			}
+		}
 		if (argc < 3) {
 			error("too few parameters");
 			usage_with_options(git_notes_usage, options);