written = php_stream_write(s, buf, len);
if (written != len) {
- php_error_docref(NULL, E_WARNING, "Failed to append %zu bytes to body; wrote %zu", len, written);
+ php_error_docref(NULL, E_WARNING, "Failed to append %zu bytes to body; wrote %zu", len, written == (size_t) -1 ? 0 : written);
}
return len;