ProjectExplorer: Nodes: Do not makeEmpty() as part of buildTree()

Do not call makeEmpty() as part of buildTree(). That makes it
impossible to combine buildTree with manual tree setup.

Change-Id: If0a0d9432fe39870917a6ba31594e8dcd6d31868
Reviewed-by: hjk <hjk@qt.io>

src/plugins/autotoolsprojectmanager/autotoolsproject.cpp

@@ -229,6 +229,7 @@ void AutotoolsProject::makefileParsingFinished()
                              f == QLatin1String("configure.ac")) ? FileType::Project : FileType::Resource,
                             false);
     });
+    rootProjectNode()->makeEmpty();
     rootProjectNode()->buildTree(fileNodes);
 
     updateCppCodeModel();

src/plugins/genericprojectmanager/genericproject.cpp

@@ -282,6 +282,7 @@ void GenericProject::refresh(RefreshOptions options)
                                               FileType::Project,
                                               /* generated = */ false);
         fileNodes << projectFilesNode << projectIncludesNode << projectConfigNode;
+        rootProjectNode()->makeEmpty();
         rootProjectNode()->buildTree(fileNodes);
     }
 

src/plugins/nim/project/nimproject.cpp

@@ -159,6 +159,7 @@ void NimProject::updateProject()
     if (oldFiles == m_files)
         return;
 
+    rootProjectNode()->makeEmpty();
     rootProjectNode()->buildTree(fileNodes);
 
     emit fileListChanged();

src/plugins/projectexplorer/projectnodes.cpp

@@ -478,8 +478,6 @@ FolderNode *FolderNode::recursiveFindOrCreateFolderNode(const Utils::FileName &d
 
 void FolderNode::buildTree(QList<FileNode *> &files, const Utils::FileName &overrideBaseDir)
 {
-    makeEmpty();
-
     foreach (ProjectExplorer::FileNode *fn, files) {
         // Get relative path to rootNode
         QString parentDir = fn->filePath().toFileInfo().absolutePath();

src/plugins/pythoneditor/pythoneditorplugin.cpp

@@ -618,6 +618,7 @@ void PythonProject::refresh()
         const QString displayName = baseDir.relativeFilePath(f);
         return new PythonFileNode(FileName::fromString(f), displayName);
     });
+    rootProjectNode()->makeEmpty();
     rootProjectNode()->buildTree(fileNodes);
 
     emit parsingFinished();