sfvcnt = 2;
vec[0].sfv_fd = SFV_FD_SELF;
vec[0].sfv_flag = 0;
- vec[0].sfv_off = block;
+ /* Cast to unsigned long to prevent sign extension of the
+ * pointer value for the LFS case; see Apache PR 39463. */
+ vec[0].sfv_off = (unsigned long)block;
vec[0].sfv_len = DSI_BLOCKSIZ;
vec[1].sfv_fd = fromfd;
vec[1].sfv_flag = 0;