Ensure custom uuids are returned by QBluetoothServiceInfo::serviceUuid()

QBluetoothServiceDiscoveryAgent::start(FullDiscovery) uses an external
tool called sdpscanner to perform the SDP inquiry. The tool uses Bluez's
own API to perform the task and is GPL.

In case a remote device offers a custom service the service uuid is returned
as serviceClassUuid. QBluetoothServiceInfo::serviceUuid() remains empty
although it should be populated as per API contract. This patch ensures
that the first custom uuid is shifted from the serviceClassUuid list to
serviceUuid(). The fix is limited because it picks the first custom uuid
and does not consider a secondary custom uuid. Such a case is extremely
unlikely though and I have not come across it.

Fixes: QTBUG-72800
Change-Id: I7256440bcb1c9b0b2fb75249f977c43fecf1d910
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

1 files changed, 17 insertions, 1 deletions

diff --git a/src/bluetooth/qbluetoothservicediscoveryagent_bluez.cpp b/src/bluetooth/qbluetoothservicediscoveryagent_bluez.cpp
index e16caff6..6a93143b 100644
--- a/src/bluetooth/qbluetoothservicediscoveryagent_bluez.cpp
+++ b/src/bluetooth/qbluetoothservicediscoveryagent_bluez.cpp
@@ -291,7 +291,7 @@ void QBluetoothServiceDiscoveryAgentPrivate::_q_finishSdpScan(QBluetoothServiceD
         emit q->error(error);
     } else if (!xmlRecords.isEmpty() && discoveryState() != Inactive) {
         for (const QString &record : xmlRecords) {
-            const QBluetoothServiceInfo serviceInfo = parseServiceXml(record);
+            QBluetoothServiceInfo serviceInfo = parseServiceXml(record);
 
             //apply uuidFilter
             if (!uuidFilter.isEmpty()) {
@@ -313,6 +313,22 @@ void QBluetoothServiceDiscoveryAgentPrivate::_q_finishSdpScan(QBluetoothServiceD
             if (!serviceInfo.isValid())
                 continue;
 
+            // Bluez sdpscanner declares custom uuids into the service class uuid list.
+            // Let's move a potential custom uuid from QBluetoothServiceInfo::serviceClassUuids()
+            // to QBluetoothServiceInfo::serviceUuid(). If there is more than one, just move the first uuid
+            const QList<QBluetoothUuid> serviceClassUuids = serviceInfo.serviceClassUuids();
+            for (const QBluetoothUuid &id : serviceClassUuids) {
+                if (id.minimumSize() == 16) {
+                    serviceInfo.setServiceUuid(id);
+                    serviceInfo.setServiceName(QBluetoothServiceDiscoveryAgent::tr("Custom Service"));
+                    QBluetoothServiceInfo::Sequence modSeq =
+                            serviceInfo.attribute(QBluetoothServiceInfo::ServiceClassIds).value<QBluetoothServiceInfo::Sequence>();
+                    modSeq.removeOne(QVariant::fromValue(id));
+                    serviceInfo.setAttribute(QBluetoothServiceInfo::ServiceClassIds, modSeq);
+                    break;
+                }
+            }
+
             if (!isDuplicatedService(serviceInfo)) {
                 discoveredServices.append(serviceInfo);
                 qCDebug(QT_BT_BLUEZ) << "Discovered services" << discoveredDevices.at(0).address().toString()