+
+ /* Check for multiplication overflows.
+ * This code avoids the costly division if the sizes are small enough.
+ * Multiplication is safe as long as only half of bits are set
+ * in either multiplicand.
+ */
+ const size_t check_limit = (size_t)1 << (sizeof(size_t) * 4);
+ if (data_size >= check_limit || array_size >= check_limit)
+ {
+ const size_t size_max = (size_t)-1;
+ if (size_max / array_size < data_size)
+ {
+ PB_RETURN_ERROR(stream, "size too large");
+ }
+ }