STSnavigate open a new windows in SharePoint 2013

The New (or New Document) menu item uses createNewDocumentWithRedirect function in core.js file to create a new documents (including the InfoPath form).

Here are the codes in core.js for your information.

function createNewDocumentWithRedirect(strTemplate, strSaveLocation, strProgID, bXMLForm, strRedirectUrl, defaultItemOpen) {

    if (IsClientAppInstalled(strProgID) && defaultItemOpen != 1) {

        var strIndependentProgId = strProgID.replace(/(?:\.\d+)$/, '');

        createNewDocumentWithProgID(strTemplate, strSaveLocation, strIndependentProgId, bXMLForm);

    }

    else {

        STSNavigate(strRedirectUrl + "&SaveLocation=" + makeAbsUrl(escapeProperly(strSaveLocation)) + "&Source=" + GetSource() + "&DefaultItemOpen=" + defaultItemOpen);

    }

}

function STSNavigate(Url) {

    if (isPortalTemplatePage(Url))

        window.top.location = STSPageUrlValidation(Url);

    else

        window.location = STSPageUrlValidation(Url);

}

For the codes above, as SharePoint uses window.location to navigate to the new link, the link will open in current window instead of a new window.

Therefore, you could override the STSNavigate function in the AllItems.aspx to change the behavior, here is the code sample for your information.

<asp:content contentplaceholderid="PlaceHolderAdditionalPageHead" runat="server">

       <SharePoint:RssLink runat="server"/>

      

       <Script>

       function STSNavigate(Url){

              window.open(STSPageUrlValidation(Url),"_blank");

       }

       </Script>

</asp:content>