XWIKI-20023: Move the Formula macro to XWiki Contrib

* Fix bug for URL resolving which were resolved with the file:// scheme by FOP
* I couldn't find how to tell FOP what base URI to use for URL resolving

xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/internal/pdf/FOPXSLFORenderer.java

@@ -274,10 +274,12 @@ private void setCacheFile(FontManager fontManager) throws InitializationExceptio
     }
 
     /**
-     * Use the instance base URL as the FOP base URI so that the relative URLs returned by XWiki when rendering a page
-     * in view mode (for browser consumption - it's a best practice to return relative URLs and let browsers convert
-     * them to full URLs) are properly converted by FOP to full URIs before
-     * {@link org.apache.xmlgraphics.io.ResourceResolver#getResource(URI)} is called.
+     * Use the instance base URL as the FOP base URI so that any relative URLs returned by XWiki when rendering a
+     * page in view mode (for browser consumption - it's a best practice to return relative URLs and let browsers
+     * convert them to full URLs) are properly converted by FOP to full URIs before
+     * {@link org.apache.xmlgraphics.io.ResourceResolver#getResource(URI)} is called. Note that we currently use
+     * {@link com.xpn.xwiki.web.ExternalServletURLFactory} in {@link com.xpn.xwiki.web.ExportAction} and thus all
+     * URLs arriving in FOP should already be absolute.
      */
     private URI getBaseURI() throws InitializationException
     {

xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/ExportAction.java

@@ -164,11 +164,7 @@ private String export(String format, XWikiContext context) throws XWikiException
         // Note 1: exportType will be null if no office server is started or it doesn't support the passed format
         // Note 2: we don't use the office server for PDF exports since it doesn't work OOB. Instead we use FOP.
         if ("pdf".equalsIgnoreCase(format)) {
-            // Use the factory to generate view URLs for browser-consumption. FOP will resolve any relative URL to
-            // a full URI, see FOPXSLFORenderer#getBaseURI(). Note that this is a better implementation than using
-            // ExternalServletURLFactory since that would only work for URLs that are computed using XWikiURLFactory
-            // and not those using a ResourceReferenceSerializer (e.g. ExtendedURLTemporaryResourceReferenceSerializer).
-            urlFactory = new XWikiServletURLFactory();
+            urlFactory = new ExternalServletURLFactory();
             exporter = new PdfExportImpl();
             exportType = ExportType.PDF;
         } else if (exportType == null) {