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

Author: matriv

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

@@ -264,6 +264,9 @@ 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

@@ -21,16 +21,19 @@
 import org.elasticsearch.xpack.sql.expression.predicate.operator.arithmetic.Add;
 import org.elasticsearch.xpack.sql.expression.predicate.operator.arithmetic.Mul;
 import org.elasticsearch.xpack.sql.expression.predicate.operator.arithmetic.Sub;
+import org.elasticsearch.xpack.sql.proto.SqlTypedParamValue;
 
 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.ql.type.DataTypes.BOOLEAN;
 import static org.elasticsearch.xpack.ql.type.DataTypes.DOUBLE;
 import static org.elasticsearch.xpack.ql.type.DataTypes.INTEGER;
+import static org.elasticsearch.xpack.ql.type.DataTypes.KEYWORD;
 import static org.elasticsearch.xpack.ql.type.DataTypes.LONG;
 import static org.hamcrest.Matchers.startsWith;
 
@@ -542,4 +545,11 @@ 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());
+    }
 }