Program: 4121
Project: 4121
Buggy source:
public static void visitTemplatePath(@NotNull Project project,final @NotNull TemplatePath templatePath,@NotNull final ViewVisitor visitor){
  final VirtualFile templateDir=VfsUtil.findRelativeFile(templatePath.getPath(),project.getBaseDir());
  if (templateDir == null) {
    return;
  }
  VfsUtil.visitChildrenRecursively(templateDir,new VirtualFileVisitor(){
    @Override public boolean visitFile(    @NotNull VirtualFile virtualFile){
      if (virtualFile.isDirectory() || !isTemplateFile(virtualFile)) {
        return true;
      }
      String filename=VfsUtil.getRelativePath(virtualFile,templateDir,'.');
      if (filename == null) {
        return true;
      }
      if (filename.endsWith("String_Node_Str")) {
        filename=filename.substring(0,filename.length() - 4);
      }
      if (filename.endsWith("String_Node_Str")) {
        filename=filename.substring(0,filename.length() - 6);
      }
      if (filename.endsWith("String_Node_Str")) {
        filename=filename.substring(0,filename.length() - "String_Node_Str".length());
      }
      if (templatePath.getNamespace() != null) {
        visitor.visit(virtualFile,templatePath.getNamespace() + "String_Node_Str" + filename);
      }
 else {
        visitor.visit(virtualFile,filename);
      }
      return true;
    }
    private boolean isTemplateFile(    VirtualFile virtualFile){
      if (virtualFile.getFileType() == BladeFileType.INSTANCE || virtualFile.getFileType() == PhpFileType.INSTANCE) {
        return true;
      }
      String extension=virtualFile.getExtension();
      if (extension != null && (extension.equalsIgnoreCase("String_Node_Str") || extension.equalsIgnoreCase("String_Node_Str"))) {
        return true;
      }
      return false;
    }
  }
);
}

Fixed version (ground truth):
public static void visitTemplatePath(@NotNull Project project,final @NotNull TemplatePath templatePath,@NotNull final ViewVisitor visitor){
  final VirtualFile templateDir=VfsUtil.findRelativeFile(templatePath.getPath(),project.getBaseDir());
  if (templateDir == null) {
    return;
  }
  VfsUtil.visitChildrenRecursively(templateDir,new VirtualFileVisitor(){
    @Override public boolean visitFile(    @NotNull VirtualFile virtualFile){
      if (virtualFile.isDirectory() || !isTemplateFile(virtualFile)) {
        return true;
      }
      String filename=VfsUtil.getRelativePath(virtualFile,templateDir,'.');
      if (filename == null) {
        return true;
      }
      if (filename.endsWith("String_Node_Str")) {
        filename=filename.substring(0,filename.length() - 4);
      }
      if (filename.endsWith("String_Node_Str")) {
        filename=filename.substring(0,filename.length() - 6);
      }
      if (filename.endsWith("String_Node_Str")) {
        filename=filename.substring(0,filename.length() - "String_Node_Str".length());
      }
      String namespace=templatePath.getNamespace();
      if (namespace != null && StringUtils.isNotBlank(namespace)) {
        visitor.visit(virtualFile,namespace + "String_Node_Str" + filename);
      }
 else {
        visitor.visit(virtualFile,filename);
      }
      return true;
    }
    private boolean isTemplateFile(    VirtualFile virtualFile){
      if (virtualFile.getFileType() == BladeFileType.INSTANCE || virtualFile.getFileType() == PhpFileType.INSTANCE) {
        return true;
      }
      String extension=virtualFile.getExtension();
      if (extension != null && (extension.equalsIgnoreCase("String_Node_Str") || extension.equalsIgnoreCase("String_Node_Str"))) {
        return true;
      }
      return false;
    }
  }
);
}