ProjectNodes: Sprinkle QTC_ASSERT over code looking at parentFolderNode

Not checking the parentFolderNode triggered a crash elsewhere already, so
double check other uses of parentFolderNode and use QTC_ASSERT to make sure
no nullptr is going to be accessed.

This is necessary now that we have a forest of project trees and no longer
have a sessionnode anymore.

Change-Id: Ibc380c2ec9b12b983e709d2eeb03a8b741fe1058
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/projectexplorer/projectexplorer.cpp

@@ -3323,6 +3323,7 @@ void ProjectExplorerPlugin::renameFile(Node *node, const QString &newFilePath)
 {
     const QString oldFilePath = node->filePath().toFileInfo().absoluteFilePath();
     FolderNode *folderNode = node->parentFolderNode();
+    QTC_ASSERT(folderNode, return);
     const QString projectFileName = folderNode->managingProject()->filePath().fileName();
 
     if (oldFilePath == newFilePath)

src/plugins/qmakeprojectmanager/qmakenodes.cpp

@@ -84,9 +84,11 @@ bool QmakePriFileNode::supportsAction(ProjectAction action, Node *node) const
 
     const FolderNode *folderNode = this;
     const QmakeProFileNode *proFileNode;
-    while (!(proFileNode = dynamic_cast<const QmakeProFileNode*>(folderNode)))
+    while (!(proFileNode = dynamic_cast<const QmakeProFileNode*>(folderNode))) {
         folderNode = folderNode->parentFolderNode();
-    Q_ASSERT(proFileNode);
+        QTC_ASSERT(folderNode, return false);
+    }
+    QTC_ASSERT(proFileNode, return false);
     const QmakeProFile *pro = proFileNode->proFile();
 
     switch (pro ? pro->projectType() : ProjectType::Invalid) {

src/plugins/qmakeprojectmanager/qmakeproject.cpp

@@ -611,6 +611,7 @@ QStringList QmakeProject::filesGeneratedFrom(const QString &input) const
 
     if (const FileNode *file = fileNodeOf(rootProjectNode(), FileName::fromString(input))) {
         const QmakeProFileNode *pro = static_cast<QmakeProFileNode *>(file->parentFolderNode());
+        QTC_ASSERT(pro, return {});
         if (const QmakeProFile *proFile = pro->proFile())
             return Utils::transform(proFile->generatedFiles(FileName::fromString(pro->buildDir()),
                                                             file->filePath(), file->fileType()),

src/plugins/resourceeditor/resourceeditorplugin.cpp

@@ -287,6 +287,7 @@ void ResourceEditorPlugin::removeFileContextMenu()
     QTC_ASSERT(rfn, return);
     QString path = rfn->filePath().toString();
     FolderNode *parent = rfn->parentFolderNode();
+    QTC_ASSERT(parent, return);
     if (!parent->removeFiles(QStringList() << path))
         QMessageBox::warning(Core::ICore::mainWindow(),
                              tr("File Removal Failed"),

src/plugins/resourceeditor/resourcenode.cpp

@@ -70,8 +70,9 @@ public:
     {
         if (type == TypePermissions)
             return true;
-        auto newNode = new ResourceTopLevelNode(m_node->filePath(), false, m_node->contents(),
+        FolderNode *parent = m_node->parentFolderNode();
-                                                m_node->parentFolderNode());
+        QTC_ASSERT(parent, return false);
+        auto newNode = new ResourceTopLevelNode(m_node->filePath(), false, m_node->contents(), parent);
         m_node->parentFolderNode()->replaceSubtree(m_node, newNode);
         return true;
     }