p:fileUpload Cancel fileUpload when fileLimit exceeded

I have a JSF application with Primefaces 5.1.

<p:fileUpload id="file-upload-input1" label="#{msg['fileUpload.attachment']}" auto="true"
                                          fileUploadListener="#{fileUploadController.uploadFile}"
                                          widgetVar="fileUploadWidget"
                                          mode="advanced"
                                          onstart="PF('loadingDialog').show();"
                                          fileLimit="30"
                                          oncomplete="onCompleteAllFiles(this);"
                                          onerror="alert('Error. Try again')"
                                          invalidFileMessage="#{msg['fileUpload.file.invalid.type']}"
                                          invalidSizeMessage="#{msg['fileUpload.file.invalid.size']}"
                                          sizeLimit="3221223823"
                                          multiple="true"
                                          allowTypes="/(\.|\/)(xml|pdf)$/" update="file-upload-info"/>

It seems that the fileLimit parameter doesn't cancel the whole file upload. It just cancels upload for the files exceeding the limit. I want to disable uploading the whole bulk and inform user that there is a limit and he should try again with correct amount of files.

I've tried with a solution suggested by

https://stackoverflow.com/a/47473958

to validate the form before submitting, but I'm not able to obtain amount of files:

    var fnRef = function (event) {
                console.log("Button clicked");
                if (triggerValidation) {
                    //prevent file browser to open
                    event.preventDefault();
                    //trigger validation via p:remoteCommand;
                    submitSelection();
                } else {
                    //File browser will be opened at this point
                }
            };

How can I cancel the WHOLE upload, when fileLimit validation fails?