type_decoder: update .samplenum before ending .wait() with EOFError

When the protocol decoder's input data is exhausted, then the .wait()
method will raise the EOFError exception. Python decoders can catch this
exception and handle the condition. For proper annotation emission it is
essential that the self.samplenum value corresponds to the last position
in the input stream. Update it before returning from the .wait() call.

Author: gsigh

type_decoder.c

@@ -1098,6 +1098,11 @@ static PyObject *Decoder_wait(PyObject *self, PyObject *args)
 		 * when the sample data is exhausted.
 		 */
 		if (di->communicate_eof) {
+			/* Advance self.samplenum to the (absolute) last sample number. */
+			py_samplenum = PyLong_FromUnsignedLongLong(di->abs_cur_samplenum);
+			PyObject_SetAttrString(di->py_inst, "samplenum", py_samplenum);
+			Py_DECREF(py_samplenum);
+			/* Raise an EOFError Python exception. */
 			srd_dbg("%s: %s: Raising EOF from wait().",
 				di->inst_id, __func__);
 			g_mutex_unlock(&di->data_mutex);