SerialUSB.available() returns wrong value/only first byte

[ghost]

There is a problem with SerialUSB.available() if using Arduino Zero board.
I send 4 bytes, Terminal output switched from 0 to 4 (but sometimes it only shows 1). Now, if i send another 4 bytes, terminal output dont switch to 8. It still shows only 4.
It seems if available() method executed following received bytes are ignored.

Test sketch

void setup()
{
	SerialUSB.begin(115200);
	while(!SerialUSB);
}
void loop()
{
	int availableBytes = SerialUSB.available();
	SerialUSB.println(availableBytes, DEC);
	delay(1000);
}

Test procedure:

• burn sketch
• open terminal
• terminal receive a 0 every second
• send 4 bytes
• now terminal receive a 1 or 4 every second
• send another bytes
• terminal should receive 8 but still get a 1 or 4 every second

*edit
If using Serial instead of SerialUSB the problem not occurs.

[ghost]

Bug is still there

[facchinm]

Fixed by c8094e7