Allow QQmlComponent::loadUrl() to load absolute URLs with relative paths

Currently, QQmlTypeLoader::getType() will assert if passed a relative
URL, because it needs absolute URLs in order to ensure that it can use
them as keys for its cache. After dc6b73390 was merged, URLs like
QUrl::fromLocalFile("main.qml") (which are currently used in examples
of how to load a QQmlComponent) started causing the assertion to fail.

As mentioned in the comments of the bug report, some patches have
already been applied to QQmlComponent's QString-based constructors,
but both the constructors taking a QUrl and loadUrl() itself need
fixing.

This patch puts the fix into loadUrl() (the constructors call this
function) so that every operation
involving URLs is successful when using the documented methods.

Task-number: QTBUG-58837
Change-Id: Ib54ca52eddce6e7781cf96015f4c15af604233d3
Reviewed-by: David Faure <david.faure@kdab.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/src/qml/doc/src/includes/qqmlcomponent.qdoc b/src/qml/doc/src/includes/qqmlcomponent.qdoc
new file mode 100644
index 0000000000..0eb60ed743
--- /dev/null
+++ b/src/qml/doc/src/includes/qqmlcomponent.qdoc
@@ -0,0 +1,58 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation 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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//! [url-note]
+Ensure that the URL provided is full and correct, in particular, use
+\l QUrl::fromLocalFile() when loading a file from the local filesystem.
+
+Relative paths will be resolved against the engine's
+\l {QQmlEngine::baseUrl}{baseUrl()}, which is the current working directory
+unless specified.
+//! [url-note]