add comment about xz format support

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/libbb/read.c b/libbb/read.c
index 503216eb5a99399edc24fc28ff861824408612b4..21e005c6f02f910fde0579f20f9a4d14665cbf80 100644 (file)
--- a/libbb/read.c
+++ b/libbb/read.c
@@ -334,6 +334,11 @@ int FAST_FUNC setup_unzip_on_fd(int fd /*, int fail_if_not_detected*/)
                if (!ENABLE_FEATURE_SEAMLESS_BZ2
                 || magic[0] != 'B' || magic[1] != 'Z'
                ) {
+
+// TODO: xz format support. rpm adopted it, "rpm -i FILE.rpm" badly needs this.
+// Signature: 0xFD, '7', 'z', 'X', 'Z', 0x00
+// More info at: http://tukaani.org/xz/xz-file-format.txt
+
                        if (fail_if_not_detected)
                                bb_error_msg_and_die("no gzip"
                                        IF_FEATURE_SEAMLESS_BZ2("/bzip2")