xz: add a comment about using uint32_t as vli_type

Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/archival/libarchive/unxz/xz_stream.h b/archival/libarchive/unxz/xz_stream.h
index 2ffaa34ea..66cb5a705 100644
--- a/archival/libarchive/unxz/xz_stream.h
+++ b/archival/libarchive/unxz/xz_stream.h
@@ -32,8 +32,13 @@
 #define FOOTER_MAGIC_SIZE 2
 
 /*
- * Variable-length integer can hold a 63-bit unsigned integer, or a special
- * value to indicate that the value is unknown.
+ * Variable-length integer can hold a 63-bit unsigned integer or a special
+ * value indicating that the value is unknown.
+ *
+ * Experimental: vli_type can be defined to uint32_t to save a few bytes
+ * in code size (no effect on speed). Doing so limits the uncompressed and
+ * compressed size of the file to less than 256 MiB and may also weaken
+ * error detection slightly.
  */
 typedef uint64_t vli_type;