Prevent limit of search outbounding max int value

The problem occurs when IndexConfig is created with the
default value, i.e., Integer.MAX_VALUE, and the start
value in the QueryOptions instance is greater than 0.

Bug: Issue 4006
Change-Id: Ib746a7941505a10e0c5a2b1d0a3ca79fca11de5f

gerrit-lucene/src/main/java/com/google/gerrit/lucene/LuceneChangeIndex.java

@@ -447,6 +447,9 @@ public class LuceneChangeIndex implements ChangeIndex {
       IndexSearcher[] searchers = new IndexSearcher[indexes.size()];
       try {
         int realLimit = opts.start() + opts.limit();
+        if (Integer.MAX_VALUE - opts.limit() < opts.start()) {
+          realLimit = Integer.MAX_VALUE;
+        }
         TopFieldDocs[] hits = new TopFieldDocs[indexes.size()];
         for (int i = 0; i < indexes.size(); i++) {
           searchers[i] = indexes.get(i).acquire();