Merge remote-tracking branch 'origin/master'

examcloud-core-oe-admin-service/src/main/java/cn/com/qmth/examcloud/core/oe/admin/service/impl/ExamStudentServiceImpl.java

@@ -793,7 +793,11 @@ public class ExamStudentServiceImpl implements ExamStudentService {
             startCount=eb.getStartCount();
             endCount=eb.getEndCount();
         }
-        return canExamTimes+extraNum-(usedNum+startCount-endCount);
+        Integer ret=canExamTimes+extraNum-(usedNum+startCount-endCount);
+        if(ret<0) {
+            ret=0;
+        }
+        return ret;
     }
     
 }