FS-7378 play_and_detect_speech: protect against NULL result

src/mod/applications/mod_dptools/mod_dptools.c

@@ -515,7 +515,9 @@ SWITCH_STANDARD_APP(play_and_detect_speech_function)
 		char *grammar = argv[1];
 		char *result = NULL;
 		switch_ivr_play_and_detect_speech(session, file, engine, grammar, &result, 0, NULL);
-		switch_channel_set_variable(channel, "detect_speech_result", result);
+		if (!zstr(result)) {
+			switch_channel_set_variable(channel, "detect_speech_result", result);
+		}
 	} else {
 		/* bad input */
 		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Usage: %s\n", PLAY_AND_DETECT_SPEECH_SYNTAX);

src/switch_ivr_async.c

@@ -3928,7 +3928,7 @@ SWITCH_DECLARE(switch_status_t) switch_ivr_play_and_detect_speech(switch_core_se
 	switch_status_t status = SWITCH_STATUS_SUCCESS;
 	int recognizing = 0;
 	switch_input_args_t myargs = { 0 };
-	play_and_detect_speech_state_t state = { 0 };
+	play_and_detect_speech_state_t state = { 0, "" };
 	switch_channel_t *channel = switch_core_session_get_channel(session);
 
 	arg_recursion_check_start(args);