Uploaded image for project: 'MariaDB Server'
  1. MariaDB Server
  2. MDEV-29188

Crash in JSON_EXTRACT

Details

    Description

      The following test will crash 10.4 but not 10.3:

      CREATE TABLE t1 (j JSON);
      		 
       
      		 
      INSERT INTO t1 VALUES
      		 
        ('{"ID": "4", "Name": "Betty", "Age": 19}'),
      		 
        ('[10, 20, [30, 40]]');
      		 
       
      		 
      SELECT * FROM t1 WHERE JSON_EXTRACT(j, '$.Age')=19;

      This was reduced from the crash in the test spider/bugfix.mdev_24517 after a merge from 10.3 to 10.4 in on a CI builder:

      10.4 3bb36e949534fc4a24d68d4297663ae8b80ba336

      		 
      CURRENT_TEST: spider/bugfix.mdev_24517
      		 
      mysqltest: At line 57: query 'SELECT * FROM tbl_a WHERE JSON_EXTRACT(j, '$.Age')=19' failed: 1158: Got an error reading communication packets

      The following would fix it, but cause an inconsistent result in the test main.func_json:

      diff --git a/sql/item_jsonfunc.cc b/sql/item_jsonfunc.cc
      		 
      index 93ebb520ffc..5794ac952bf 100644
      		 
      --- a/sql/item_jsonfunc.cc
      		 
      +++ b/sql/item_jsonfunc.cc
      		 
      @@ -1107,7 +1107,8 @@ my_decimal *Item_func_json_extract::val_decimal(my_decimal *to)
      		 
           };
      		 
         }
      		 
         int2my_decimal(E_DEC_FATAL_ERROR, 0, false/*unsigned_flag*/, to);
      		 
      -  return to;
      		 
      +  null_value= 1;
      		 
      +  return 0;
      		 
       }

      The result difference is as follows:

      CURRENT_TEST: main.func_json
      		 
      --- /mariadb/10.4/mysql-test/main/func_json.result	2022-02-10 16:53:33.683230501 +0200
      		 
      +++ /mariadb/10.4/mysql-test/main/func_json.reject	2022-07-28 09:13:13.375261554 +0300
      		 
      @@ -932,7 +932,7 @@
      		 
       CAST(JSON_EXTRACT('{"x":false}', '$.x') AS DOUBLE) AS cf,
      		 
       CAST(JSON_EXTRACT('{"x":false}', '$.x') AS DECIMAL) AS cd;
      		 
       cf	cd
      		 
      -0	0
      		 
      +0	NULL
      		 
       #
      		 
       # MDEV-24585 Assertion `je->s.cs == nice_js->charset()' failed in json_nice.
      		 
       #

      I think that it would be consistent to return NULL on any error (including the conversion to DOUBLE).

      Attachments

        Activity

          People

            sanja Oleksandr Byelkin
            marko Marko Mäkelä
            Votes:
            0 Vote for this issue
            Watchers:
            4 Start watching this issue

            Dates

              Created:
              Updated:
              Resolved:

              Git Integration

                Error rendering 'com.xiplink.jira.git.jira_git_plugin:git-issue-webpanel'. Please contact your Jira administrators.