fix: handle null operands in LogicOrOperator for consistency with && and !

src/main/java/com/alibaba/qlexpress4/runtime/operator/logic/LogicOrOperator.java

@@ -36,6 +36,13 @@ public Object execute(Value left, Value right, QRuntime qRuntime, QLOptions qlOp
         ErrorReporter errorReporter) {
         Object leftValue = left.get();
         Object rightValue = right.get();
+        if (leftValue == null) {
+            leftValue = false;
+        }
+        if (rightValue == null) {
+            rightValue = false;
+        }
+
         if (!(leftValue instanceof Boolean) || !(rightValue instanceof Boolean)) {
             throw buildInvalidOperandTypeException(left, right, errorReporter);
         }

src/test/resources/testsuite/independent/operator/logic_or_null.ql

@@ -0,0 +1,30 @@
+// || operator: null should be treated as false, consistent with && and !
+assert(true || true)
+assert(true || false)
+assert(false || true)
+assertFalse(false || false)
+
+// || with null operands: null is treated as false
+assert(true || null)
+assert(null || true)
+assertFalse(false || null)
+assertFalse(null || false)
+assertFalse(null || null)
+
+// 'or' keyword: same behavior as ||
+assert(true or true)
+assert(true or false)
+assert(false or true)
+assertFalse(false or false)
+
+// 'or' with null operands
+assert(true or null)
+assert(null or true)
+assertFalse(false or null)
+assertFalse(null or false)
+assertFalse(null or null)
+
+// consistency with ! (not): !null == true, so null || true should be true
+assert(!null)
+assert(!null || false)
+assert(false || !null)