--- /dev/null
+# Test that pb_check_proto3_default_value() correctly skips padding
+# bytes in submessage structures.
+
+Import("env")
+
+env.NanopbProto("padding")
+
+p = env.Program(["padding.c",
+ "padding.pb.c",
+ "$COMMON/pb_encode.o",
+ "$COMMON/pb_common.o"])
+
+env.RunTest(p)
+
--- /dev/null
+#include <pb_encode.h>
+#include <unittests.h>
+#include <string.h>
+#include "padding.pb.h"
+
+int main()
+{
+ int status = 0;
+
+ TestMessage msg;
+
+ /* Set padding bytes to garbage */
+ memset(&msg, 0xAA, sizeof(msg));
+
+ /* Set all meaningful fields to 0 */
+ msg.submsg.boolfield = false;
+ msg.submsg.intfield = 0;
+
+ /* Test encoding */
+ {
+ pb_byte_t buf[128] = {0};
+ pb_ostream_t stream = pb_ostream_from_buffer(buf, sizeof(buf));
+ TEST(pb_encode(&stream, TestMessage_fields, &msg));
+
+ /* Because all fields have zero values, proto3 encoder
+ * shouldn't write out anything. */
+ TEST(stream.bytes_written == 0);
+ }
+
+ return status;
+}
+