[CALCITE-7398] Incorrect int cast in VariantNonNull#cast for BIGINT

Signed-off-by: Heng Qian <[email protected]>

Author: qianheng-aws

core/src/main/java/org/apache/calcite/runtime/variant/VariantNonNull.java

@@ -286,7 +286,7 @@ public class VariantNonNull extends VariantSqlValue {
           break;
         }
         case BIGINT: {
-          long l = (int) value;
+          long l = (long) value;
           switch (type.getTypeName()) {
           case TINYINT:
           case SMALLINT:

testkit/src/main/java/org/apache/calcite/test/SqlOperatorTest.java

@@ -1868,6 +1868,8 @@ void testCastToBoolean(CastType castType, SqlOperatorFixture f) {
         "INTEGER ARRAY");
     f.checkScalar("cast(cast('abc' as VARIANT) AS VARCHAR)", "abc", "VARCHAR");
     f.checkScalar("cast(cast('abc' as VARIANT) AS CHAR(3))", "abc", "CHAR(3)");
+    // Test for [CALCITE-7398] Incorrect int cast in VariantNonNull#cast for BIGINT
+    f.checkScalar("cast(cast(2147483648 as VARIANT) as DECIMAL)", "2147483648", "DECIMAL(19, 0)");
 
     // Converting a variant to anything that does not match the runtime type returns null
     f.checkScalar("cast(cast(1 as VARIANT) as INTEGER)", "1", "INTEGER");