fix LuceneQueryBuilder for "x = null" where x is numeric or boolean

This actually isn't a problem in 0.48 because the "= null"
case is handled during normalization or analysis. But it is
a problem in 0.47 for "where x in (null)" where this will
result in a Range query from null to null which matches
everything

sql/src/main/java/io/crate/lucene/QueryBuilderHelper.java

@@ -8,6 +8,8 @@
 import org.apache.lucene.search.*;
 import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.common.lucene.BytesRefs;
+import org.elasticsearch.common.lucene.search.MatchNoDocsFilter;
+import org.elasticsearch.common.lucene.search.Queries;
 
 public abstract class QueryBuilderHelper {
 
@@ -53,10 +55,16 @@ public static QueryBuilderHelper forType(DataType dataType) {
     public abstract Query rangeQuery(String columnName, Object from, Object to, boolean includeLower, boolean includeUpper);
 
     public Filter eqFilter(String columnName, Object value) {
+        if (value == null) {
+            return new MatchNoDocsFilter();
+        }
         return rangeFilter(columnName, value, value, true, true);
     }
 
     public Query eq(String columnName, Object value) {
+        if (value == null) {
+            return Queries.newMatchNoDocsQuery();
+        }
         return rangeQuery(columnName, value, value, true, true);
     }
 
@@ -77,6 +85,9 @@ public Query rangeQuery(String columnName, Object from, Object to, boolean inclu
 
         @Override
         public Query eq(String columnName, Object value) {
+            if (value == null) {
+                return Queries.newMatchNoDocsQuery();
+            }
             return new TermQuery(new Term(columnName, value == true ? "T" : "F"));
         }
     }

sql/src/test/java/io/crate/lucene/LuceneQueryBuilderTest.java

@@ -78,6 +78,24 @@ public void testNoMatchWhereClause() throws Exception {
         assertThat(query, instanceOf(MatchNoDocsQuery.class));
     }
 
+    @Test
+    public void testWhereRefEqNullInteger() throws Exception {
+        Reference foo = createReference("foo", DataTypes.INTEGER);
+        Query query = convert(whereClause(EqOperator.NAME, foo, Literal.newLiteral(DataTypes.INTEGER, null)));
+
+        // shouldn't become a range query because  from null to null is basically match all
+        assertThat(query, instanceOf(MatchNoDocsQuery.class));
+    }
+
+    @Test
+    public void testWhereRefEqNullBoolean() throws Exception {
+        Reference foo = createReference("foo", DataTypes.BOOLEAN);
+        Query query = convert(whereClause(EqOperator.NAME, foo, Literal.newLiteral(DataTypes.BOOLEAN, null)));
+
+        // shouldn't become a TermQuery because otherwise  where b = null would match columns where b = false
+        assertThat(query, instanceOf(MatchNoDocsQuery.class));
+    }
+
     @Test
     public void testWhereRefEqRef() throws Exception {
         Reference foo = createReference("foo", DataTypes.STRING);