xz: Check the value of lzma_stream_flags.version in --list.
It is a no-op for now, but if an old xz version is used
together with a newer liblzma that supports something new,
then this check becomes important and will stop the old xz
from trying to parse files that it won't understand.
diff --git a/src/xz/list.c b/src/xz/list.c
index 13abd8f..449c2bc 100644
--- a/src/xz/list.c
+++ b/src/xz/list.c
@@ -230,6 +230,20 @@
goto error;
}
+ // Check that the Stream Footer doesn't specify something
+ // that we don't support. This can only happen if the xz
+ // version is older than liblzma and liblzma supports
+ // something new.
+ //
+ // It is enough to check Stream Footer. Stream Header must
+ // match when it is compared against Stream Footer with
+ // lzma_stream_flags_compare().
+ if (footer_flags.version != 0) {
+ message_error("%s: %s", pair->src_name,
+ message_strm(LZMA_OPTIONS_ERROR));
+ goto error;
+ }
+
// Check that the size of the Index field looks sane.
lzma_vli index_size = footer_flags.backward_size;
if ((lzma_vli)(pos) < index_size + LZMA_STREAM_HEADER_SIZE) {
