update seamless uncompression code

[platform/upstream/busybox.git] / archival / libarchive / decompress_unxz.c

diff --git a/archival/libarchive/decompress_unxz.c b/archival/libarchive/decompress_unxz.c
index 3e5d4ed..79b48a1 100644 (file)
--- a/archival/libarchive/decompress_unxz.c
+++ b/archival/libarchive/decompress_unxz.c
@@ -38,7 +38,7 @@ static uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
 #include "unxz/xz_dec_stream.c"
 
 IF_DESKTOP(long long) int FAST_FUNC
-unpack_xz_stream(int src_fd, int dst_fd)
+unpack_xz_stream(transformer_aux_data_t *aux, int src_fd, int dst_fd)
 {
        struct xz_buf iobuf;
        struct xz_dec *state;
@@ -49,13 +49,17 @@ unpack_xz_stream(int src_fd, int dst_fd)
                global_crc32_table = crc32_filltable(NULL, /*endian:*/ 0);
 
        memset(&iobuf, 0, sizeof(iobuf));
-       /* Preload XZ file signature */
-       membuf = (void*) strcpy(xmalloc(2 * BUFSIZ), HEADER_MAGIC);
+       membuf = xmalloc(2 * BUFSIZ);
        iobuf.in = membuf;
-       iobuf.in_size = HEADER_MAGIC_SIZE;
        iobuf.out = membuf + BUFSIZ;
        iobuf.out_size = BUFSIZ;
 
+       if (!aux || aux->check_signature == 0) {
+               /* Preload XZ file signature */
+               strcpy((char*)membuf, HEADER_MAGIC);
+               iobuf.in_size = HEADER_MAGIC_SIZE;
+       } /* else: let xz code read & check it */
+
        /* Limit memory usage to about 64 MiB. */
        state = xz_dec_init(XZ_DYNALLOC, 64*1024*1024);