bzcat: fix unpacking of more than one file, and unpacking of zero-size bz2. Closes 4393

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

1 files changed, 8 insertions, 1 deletions

diff --git a/archival/libarchive/decompress_bunzip2.c b/archival/libarchive/decompress_bunzip2.c
index cd3144743..c4640d489 100644
--- a/archival/libarchive/decompress_bunzip2.c
+++ b/archival/libarchive/decompress_bunzip2.c
@@ -752,7 +752,14 @@ unpack_bz2_stream(int src_fd, int dst_fd)
                         }
                 }
 
-                if (i != RETVAL_LAST_BLOCK) {
+                if (i != RETVAL_LAST_BLOCK
+                /* Observed case when i == RETVAL_OK:
+                 * "bzcat z.bz2", where "z.bz2" is a bzipped zero-length file
+                 * (to be exact, z.bz2 is exactly these 14 bytes:
+                 * 42 5a 68 39 17 72 45 38  50 90 00 00 00 00).
+                 */
+                 && i != RETVAL_OK
+                ) {
                         bb_error_msg("bunzip error %d", i);
                         break;
                 }