Fix for missed scan response data (BLEScan). (espressif#4358)

This is a fix for missing scan responses after a first successfull scan.

While running the BLE_scan.ino sketch with wantDuplicates=false, i got
only one result with correct advertising and scan response length (31,26):

pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks(), false);
pBLEScan->start(scanTime, false);
...
[W][BLEScan.cpp:109] handleGAPEvent(): bytes length: 31 + 26, addr type: 1

All following calls to start() just returned the advertising data without
scan response data:

pBLEScan->start(scanTime, false);
[W][BLEScan.cpp:109] handleGAPEvent(): bytes length: 31 + 0, addr type: 1

With "wantDuplicates=true" i got:

pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks(), true);
pBLEScan->start(scanTime, false);
[W][BLEScan.cpp:109] handleGAPEvent(): bytes length: 31 + 26, addr type: 1
[W][BLEScan.cpp:109] handleGAPEvent(): bytes length: 31 + 26, addr type: 1
[W][BLEScan.cpp:73] handleGAPEvent(): ESP_GAP_SEARCH_INQ_CMPL_EVT
Devices found: 1
Scan done!
pBLEScan->start(scanTime, false);
[W][BLEScan.cpp:109] handleGAPEvent(): bytes length: 31 + 0, addr type: 1
[W][BLEScan.cpp:109] handleGAPEvent(): bytes length: 0 + 26, addr type: 1
[W][BLEScan.cpp:109] handleGAPEvent(): bytes length: 31 + 0, addr type: 1
[W][BLEScan.cpp:109] handleGAPEvent(): bytes length: 0 + 26, addr type: 1

Explicitly initializing m_scan_params.scan_duplicate of BLEScan solves
this issue (In my case the un-initialized value was
m_scan_params.scan_duplicate == 1073599044).

Co-authored-by: Me No Dev <[email protected]>

Author: jensh

libraries/BLE/src/BLEScan.cpp

@@ -22,6 +22,7 @@
  * Constructor
  */
 BLEScan::BLEScan() {
+	memset(&m_scan_params, 0, sizeof(m_scan_params)); // Initialize all params
 	m_scan_params.scan_type          = BLE_SCAN_TYPE_PASSIVE; // Default is a passive scan.
 	m_scan_params.own_addr_type      = BLE_ADDR_TYPE_PUBLIC;
 	m_scan_params.scan_filter_policy = BLE_SCAN_FILTER_ALLOW_ALL;