SQL: Fix NPE for parameterized LIKE/RLIKE (#53573)

Fix NPE when `null` is passed as a parameter for a parameterized
pattern of LIKE/RLIKE. e.g.: `field LIKE ?` params=[null]`
Check for null pattern in LIKE/RLIKE as for RLIKE (RegexpQuery) we
get an IllegalArgumentExpression from Lucence but for LIKE
(WildcardQuery) we get an NPE.

Fixes: #53557
(cherry picked from commit ec3481e)

x-pack/plugin/sql/src/main/java/org/elasticsearch/xpack/sql/parser/ExpressionBuilder.java

@@ -263,6 +263,9 @@ public LikePattern visitPattern(PatternContext ctx) {
         }
 
         String pattern = string(ctx.value);
+        if (pattern == null) {
+            throw new ParsingException(source(ctx.value), "Pattern must not be [null]");
+        }
         int pos = pattern.indexOf('*');
         if (pos >= 0) {
             throw new ParsingException(source(ctx.value),

x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/parser/ExpressionTests.java

@@ -21,14 +21,17 @@
 import org.elasticsearch.xpack.sql.expression.predicate.operator.comparison.Equals;
 import org.elasticsearch.xpack.sql.expression.predicate.operator.comparison.NotEquals;
 import org.elasticsearch.xpack.sql.expression.predicate.operator.comparison.NullEquals;
+import org.elasticsearch.xpack.sql.proto.SqlTypedParamValue;
 import org.elasticsearch.xpack.sql.type.DataType;
 
 import java.time.Duration;
 import java.time.Period;
 import java.time.temporal.TemporalAmount;
+import java.util.Collections;
 import java.util.Locale;
 
 import static java.lang.String.format;
+import static org.elasticsearch.xpack.sql.type.DataType.KEYWORD;
 import static org.hamcrest.Matchers.startsWith;
 
 public class ExpressionTests extends ESTestCase {
@@ -539,4 +542,11 @@ public void testCaseWithOperand() {
         assertEquals("WHEN 1 THEN 'one'", ifc.sourceText());
         assertEquals("many", c.elseResult().toString());
     }
+
+    public void testLikePatternWithNullParameterNotAllowed() {
+        ParsingException e = expectThrows(ParsingException.class,
+                () -> parser.createExpression("a LIKE ?",
+                    Collections.singletonList(new SqlTypedParamValue(KEYWORD.typeName, null))));
+        assertEquals("line 1:9: Pattern must not be [null]", e.getMessage());
+    }
 }