LE peripheral: fix a crash with unrecognized selector (iOS/macOS)

It's nice to re-use some generic functions, but it's not so if they are
actually not generic: data_from_bytearray returns NSData, not NSMutableData
and NSData (or whatever type they have under the hood) obviously does
not have replaceBytesInRange:withBytes: method and we get 'unrecognized
selector' exception  as a result.

Task-number: QTBUG-56898
Change-Id: I8fcaaf2a020c6f5caa8a171b7ac6e534fcb070cd
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

4 files changed, 23 insertions, 8 deletions

diff --git a/src/bluetooth/osx/osxbtperipheralmanager.mm b/src/bluetooth/osx/osxbtperipheralmanager.mm
index 4731fdd2..0c492aad 100644
--- a/src/bluetooth/osx/osxbtperipheralmanager.mm
+++ b/src/bluetooth/osx/osxbtperipheralmanager.mm
@@ -341,7 +341,7 @@ quint32 qt_countGATTEntries(const QLowEnergyServiceData &data)
         return;
     }
 
-    const auto nsData = data_from_bytearray(value);
+    const auto nsData = mutable_data_from_bytearray(value);
     charValues[charHandle] = nsData;
     updateQueue.push_back(UpdateRequest{charHandle, nsData});
     [self sendUpdateRequests];
@@ -530,7 +530,7 @@ quint32 qt_countGATTEntries(const QLowEnergyServiceData &data)
 
         const auto charHandle = charMap.key(request.characteristic);
         updated.insert(charHandle);
-        NSMutableData *const data = static_cast<NSMutableData *>(charValues[charHandle]);
+        NSMutableData *const data = charValues[charHandle];
         [data replaceBytesInRange:NSMakeRange(request.offset, request.value.length)
                         withBytes:data.bytes];
     }
@@ -680,7 +680,7 @@ quint32 qt_countGATTEntries(const QLowEnergyServiceData &data)
             continue;
         }
 
-        const auto nsData(data_from_bytearray(ch.value()));
+        const auto nsData(mutable_data_from_bytearray(ch.value()));
         if (!nsData) {
             qCWarning(QT_BT_OSX) << "addCharacteristicsAndDescritptors: "
                                     "addService: failed to allocate NSData (char value)";
@@ -692,7 +692,7 @@ quint32 qt_countGATTEntries(const QLowEnergyServiceData &data)
         const auto declHandle = ++lastHandle;
         // CB part:
         charMap[declHandle] = cbChar;
-        charValues[declHandle] = data_from_bytearray(ch.value());
+        charValues[declHandle] = nsData;
         // QT part:
         QLowEnergyServicePrivate::CharData charData;
         charData.valueHandle = ++lastHandle;
diff --git a/src/bluetooth/osx/osxbtperipheralmanager_p.h b/src/bluetooth/osx/osxbtperipheralmanager_p.h
index 30ddd073..3367b367 100644
--- a/src/bluetooth/osx/osxbtperipheralmanager_p.h
+++ b/src/bluetooth/osx/osxbtperipheralmanager_p.h
@@ -98,14 +98,14 @@ enum class PeripheralState
 struct UpdateRequest
 {
     UpdateRequest() = default;
-    UpdateRequest(QLowEnergyHandle handle, const ObjCStrongReference<NSData> &val)
+    UpdateRequest(QLowEnergyHandle handle, const ObjCStrongReference<NSMutableData> &val)
         : charHandle(handle),
           value(val)
     {
     }
 
     QLowEnergyHandle charHandle = {};
-    ObjCStrongReference<NSData> value;
+    ObjCStrongReference<NSMutableData> value;
 };
 
 @interface QT_MANGLE_NAMESPACE(OSXBTPeripheralManager) : NSObject<CBPeripheralManagerDelegate>
@@ -125,7 +125,7 @@ struct UpdateRequest
     ObjCScopedPointer<NSMutableDictionary> advertisementData;
 
     GenericLEMap<CBCharacteristic *> charMap;
-    GenericLEMap<ObjCStrongReference<NSData>> charValues;
+    GenericLEMap<ObjCStrongReference<NSMutableData>> charValues;
 
     std::deque<UpdateRequest> updateQueue;
 
diff --git a/src/bluetooth/osx/osxbtutility.mm b/src/bluetooth/osx/osxbtutility.mm
index adbc327b..139ccc54 100644
--- a/src/bluetooth/osx/osxbtutility.mm
+++ b/src/bluetooth/osx/osxbtutility.mm
@@ -317,6 +317,19 @@ ObjCStrongReference<NSData> data_from_bytearray(const QByteArray & qtData)
     return result;
 }
 
+ObjCStrongReference<NSMutableData> mutable_data_from_bytearray(const QByteArray &qtData)
+{
+    using MutableData = ObjCStrongReference<NSMutableData>;
+
+    if (!qtData.size())
+        return MutableData([[NSMutableData alloc] init], false);
+
+    MutableData result([[NSMutableData alloc] initWithLength:qtData.size()], false);
+    [result replaceBytesInRange:NSMakeRange(0, qtData.size())
+                      withBytes:qtData.constData()];
+    return result;
+}
+
 // A small RAII class for a dispatch queue.
 class SerialDispatchQueue
 {
diff --git a/src/bluetooth/osx/osxbtutility_p.h b/src/bluetooth/osx/osxbtutility_p.h
index 2d11692d..3c0e05e7 100644
--- a/src/bluetooth/osx/osxbtutility_p.h
+++ b/src/bluetooth/osx/osxbtutility_p.h
@@ -297,7 +297,9 @@ bool equal_uuids(const QBluetoothUuid &qtUuid, CBUUID *cbUuid);
 bool equal_uuids(CBUUID *cbUuid, const QBluetoothUuid &qtUuid);
 QByteArray qt_bytearray(NSData *data);
 QByteArray qt_bytearray(NSObject *data);
-ObjCStrongReference<NSData> data_from_bytearray(const QByteArray & qtData);
+
+ObjCStrongReference<NSData> data_from_bytearray(const QByteArray &qtData);
+ObjCStrongReference<NSMutableData> mutable_data_from_bytearray(const QByteArray &qtData);
 
 dispatch_queue_t qt_LE_queue();