Bugfix: unsafe precondition(s) violated: slice::from_raw_parts requir…

…es the pointer to be aligned and non-null, and the total size of the slice not to exceed isize::MAX

#128

src/lib.rs

@@ -617,7 +617,9 @@ where
             ffi::ARCHIVE_EOF => return Ok(written),
             value => archive_result(value, archive_reader)?,
         }
-
+        if size == 0 {
+            return Ok(written);
+        }
         let content = slice::from_raw_parts(buffer as *const u8, size);
         target.write_all(content)?;
         written += size;