Index: lucene/src/java/org/apache/lucene/search/FilteredTermsEnum.java
===================================================================
--- lucene/src/java/org/apache/lucene/search/FilteredTermsEnum.java	(revision 1001397)
+++ lucene/src/java/org/apache/lucene/search/FilteredTermsEnum.java	(working copy)
@@ -198,6 +198,8 @@
       if (doSeek) {
         doSeek = false;
         final BytesRef t = nextSeekTerm(actualTerm);
+        // Make sure we always seek forward:
+        assert actualTerm == null || t == null || t.compareTo(actualTerm) > 0: "curTerm=" + actualTerm + " seekTerm=" + t;
         if (t == null || tenum.seek(t, useTermsCache) == SeekStatus.END) {
           // no more terms to seek to or enum exhausted
           return null;
Index: lucene/src/java/org/apache/lucene/search/NumericRangeQuery.java
===================================================================
--- lucene/src/java/org/apache/lucene/search/NumericRangeQuery.java	(revision 1001397)
+++ lucene/src/java/org/apache/lucene/search/NumericRangeQuery.java	(working copy)
@@ -415,6 +415,7 @@
           NumericUtils.splitLongRange(new NumericUtils.LongRangeBuilder() {
             @Override
             public final void addRange(BytesRef minPrefixCoded, BytesRef maxPrefixCoded) {
+              assert rangeBounds.size() == 0 || rangeBounds.getLast().compareTo(minPrefixCoded) < 0;
               rangeBounds.add(minPrefixCoded);
               rangeBounds.add(maxPrefixCoded);
             }