Improve accuracy of total results count on latest pages in Stealth mode

Previously, when mixing results from local RWI and local Solr (Stealth
mode), total local Solr count could be ignored on last result pages,
when the page offset was higher than local Solr count but lower than
total RWI count.

source/net/yacy/peers/Protocol.java

@@ -1342,8 +1342,14 @@ public final class Protocol {
         }
         
         // evaluate result
-        if (docList == null || docList[0].size() == 0) {
+        final int numFound = (int) docList[0].getNumFound();
+        if (docList == null || docList[0].isEmpty()) {
             Network.log.info("SEARCH (solr), returned 0 out of 0 documents from " + (target == null ? "shard" : ("peer " + target.hash + ":" + target.getName())) + " query = " + solrQuery.toString()) ;
+            if(localsearch && offset > 0) {
+            	/* No documents were returned from Solr because the offset is too high, but we have to keep the total number of matching documents for accurate pagination.
+            	 * This case can notably happen on latest results pages, when mixing results from local RWI and local Solr ("Stealth Mode") */
+            	event.local_solr_stored.set(numFound);
+            }
             return 0;
         }
         
@@ -1427,7 +1433,6 @@ public final class Protocol {
             // add the url entry to the checked results
             resultContainer.add(urlEntry);
         }
-        final int numFound = (int) docList[0].getNumFound();
         docList[0].clear();
         docList[0] = null;
         if (localsearch) {