X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=builtin-tar-tree.c;h=58a8ccd4d6af0d755fca28b06a12ca9b8efa5300;hb=b63af9b340dd831840c70103c9f609940a910031;hp=5f740cf7025bc2a9b46656332c6a54e78ee737e4;hpb=4c068a983150b740c3fcf6a33f342ac923abd3f4;p=git.git

diff --git a/builtin-tar-tree.c b/builtin-tar-tree.c
index 5f740cf7..58a8ccd4 100644
--- a/builtin-tar-tree.c
+++ b/builtin-tar-tree.c
@@ -168,8 +168,9 @@ static int get_path_prefix(const struct strbuf *path, int maxlen)
 	int i = path->len;
 	if (i > maxlen)
 		i = maxlen;
-	while (i > 0 && path->buf[i] != '/')
+	do {
 		i--;
+	} while (i > 0 && path->buf[i] != '/');
 	return i;
 }
 
@@ -401,3 +402,28 @@ int cmd_tar_tree(int argc, const char **argv, char **envp)
 		return remote_tar(argc, argv);
 	return generate_tar(argc, argv, envp);
 }
+
+/* ustar header + extended global header content */
+#define HEADERSIZE (2 * RECORDSIZE)
+
+int cmd_get_tar_commit_id(int argc, const char **argv, char **envp)
+{
+	char buffer[HEADERSIZE];
+	struct ustar_header *header = (struct ustar_header *)buffer;
+	char *content = buffer + RECORDSIZE;
+	ssize_t n;
+
+	n = xread(0, buffer, HEADERSIZE);
+	if (n < HEADERSIZE)
+		die("git-get-tar-commit-id: read error");
+	if (header->typeflag[0] != 'g')
+		return 1;
+	if (memcmp(content, "52 comment=", 11))
+		return 1;
+
+	n = xwrite(1, content + 11, 41);
+	if (n < 41)
+		die("git-get-tar-commit-id: write error");
+
+	return 0;
+}