Merge 5.15 to dev and fix resulting compile issues

 Conflicts:
	src/imports/location/location.cpp

The change fixes the bare minimum of what needs to be done
to compile and run. This includes the following issues:

1.  Fix build failures as a result of QMetaType changes in qtbase

    moc now stores the QMetaType of properties as a result of
    46f407126ef3e94d59254012cdc34d6a4ad2faf2 in qtbase, which requires
    full type information about the property type inside the moc generated
    source file.

    Many of the property types were forward-declared, and this resulted
    in build errors like:

    "invalid application of 'sizeof' to an incomplete type 'QDeclarativeGeoMap'"

2.  Adopts QtQML API changes. A private QJSValue ctor was removed.
    The "replacement" is QJSValuePrivate::fromReturnedValue(..).

3.  The mapboxgl 3rdparty backend does not compile at this point in time
    and seems unmaintained. For the time being, the mapboxgl backend is disabled
    in the interest of keeping qtlocation closer to dev HEAD of other
    Qt modules.

Change-Id: I756e1c2effb29eaaf96a61a28c1c17338774b77c

1 files changed, 152 insertions, 0 deletions

diff --git a/examples/location/geojson_viewer/GeoJsonDelegateMapObject.qml b/examples/location/geojson_viewer/GeoJsonDelegateMapObject.qml
new file mode 100644
index 00000000..d1a144c8
--- /dev/null
+++ b/examples/location/geojson_viewer/GeoJsonDelegateMapObject.qml
@@ -0,0 +1,152 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 Paolo Angelelli <paolo.angelelli@gmail.com>
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.12
+import QtPositioning 5.12
+import Qt.labs.location 1.0
+import Qt.labs.qmlmodels 1.0
+
+DelegateChooser {
+    id: dc
+    role: "type"
+    property color defaultColor: "grey"
+
+    DelegateChoice {
+        roleValue: "Point"
+        delegate: MapCircleObject {
+            property string geojsonType: "Point"
+            property var props: modelData.properties
+            geoShape: modelData.data
+            radius: 20*1000
+            border.width: 3
+            /* The expression below is equivalent to:
+               ((props !== undefined && props["color"] !== undefined) ? props["color"] :
+               ((parent && parent.props !== undefined && parent.props["color"] !== undefined) ? parent.props["color"] : dc.defaultColor))
+            */
+            color: (props && props.color) || (parent && parent.props && parent.props.color) || dc.defaultColor
+        }
+    }
+
+    DelegateChoice {
+        roleValue: "LineString"
+        delegate: MapPolylineObject {
+            property string geojsonType: "LineString"
+            property var props: modelData.properties
+            geoShape: modelData.data
+            line.width: 4
+            line.color: (props && props.color) || (parent && parent.props && parent.props.color) || dc.defaultColor
+        }
+    }
+
+    DelegateChoice {
+        roleValue: "Polygon"
+        delegate: MapPolygonObject {
+            property string geojsonType: "Polygon"
+            property var props: modelData.properties
+            geoShape: modelData.data
+            color: (props && props.color) || (parent && parent.props && parent.props.color) || dc.defaultColor
+            border.width: 4
+            border.color: 'black'
+        }
+    }
+
+    DelegateChoice {
+        roleValue: "MultiPoint"
+        delegate: MapObjectView {
+            property string geojsonType: "MultiPoint"
+            property var props: modelData.properties
+            model: modelData.data
+            delegate: dc
+        }
+    }
+
+    DelegateChoice {
+        roleValue: "MultiLineString"
+        delegate: MapObjectView {
+            property string geojsonType: "MultiLineString"
+            property var props: modelData.properties
+            model: modelData.data
+            delegate: dc
+        }
+    }
+
+    DelegateChoice {
+        roleValue: "MultiPolygon"
+        delegate: MapObjectView {
+            property string geojsonType: "MultiPolygon"
+            property var props: modelData.properties
+            model: modelData.data
+            delegate: dc
+        }
+    }
+
+    DelegateChoice {
+        roleValue: "GeometryCollection"
+        delegate: MapObjectView {
+            property string geojsonType: "GeometryCollection"
+            property var props: modelData.properties
+            model: modelData.data
+            delegate: dc
+        }
+    }
+
+    // Features are explicitly not generated by the parser, but converted straight to their content + the properties.
+
+    DelegateChoice {
+        roleValue: "FeatureCollection"
+        delegate: MapObjectView {
+            property string geojsonType: "FeatureCollection"
+            property var props: modelData.properties
+            model: modelData.data
+            delegate: dc
+        }
+    }
+}