QmlDesigner: Fix UB in QmlPreviewPlugin::getPreviewPlugin()v4.13.0

Each call to PluginManager::plugins() creates a new QVector object,
iterators are only comparable for iterators from the same vector.

It worked in practice because the underlying storage was the same
here as the QVector objects were only shallow copies.

Change-Id: I2e276535942bd949acf91e12873c7bdf9d5c34d6
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

1 files changed, 5 insertions, 3 deletions

diff --git a/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewplugin.cpp b/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewplugin.cpp
index aa6b0e8565..ac0f30118d 100644
--- a/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewplugin.cpp
+++ b/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewplugin.cpp
@@ -158,13 +158,15 @@ void QmlPreviewPlugin::setLanguageLocale(const QString &locale)
 
 QObject *QmlPreviewPlugin::getPreviewPlugin()
 {
-    auto pluginIt = std::find_if(ExtensionSystem::PluginManager::plugins().begin(),
-                                 ExtensionSystem::PluginManager::plugins().end(),
+    const QVector<ExtensionSystem::PluginSpec *> specs = ExtensionSystem::PluginManager::plugins();
+
+    auto pluginIt = std::find_if(specs.begin(),
+                                 specs.end(),
                                  [](const ExtensionSystem::PluginSpec *p) {
         return p->name() == "QmlPreview";
     });
 
-    if (pluginIt != ExtensionSystem::PluginManager::plugins().constEnd())
+    if (pluginIt != specs.end())
         return (*pluginIt)->plugin();
 
     return nullptr;