Memory leak for json_tokener_parse_ex for version 0.12.1

[mariusor]

Hi, using a very simple example of json parsing, valgrind reports a memory leak for function json_tokener_parse_ex:

 ==19276== 711 (88 direct, 623 indirect) bytes in 1 blocks are definitely lost in loss record 11 of 11                                                                                                                                      
 ==19276==    at 0x4C2EF35: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)                                                                                                                                                 
 ==19276==    by 0x59E5F1A: lh_table_new (in /usr/lib/libjson-c.so.2.0.2)                                                                                                                                                                   
 ==19276==    by 0x59E26AD: json_object_new_object (in /usr/lib/libjson-c.so.2.0.2)                                                                                                                                                                 
 ==19276==    by 0x59E49A4: json_tokener_parse_ex (in /usr/lib/libjson-c.so.2.0.2)                                                                                                                                                          
 ==19276==    by 0x10E0EB: json_document_is_error (api.h:1044)    

The code triggering this can be seen in my project mpris-scrobbler.

The buffer string that would be matched is something like:

{"error":4,"message":"Unauthorized Token - This token has not been issued"}

Looking at the code, it seems that somehow the json_object_object_delete function is not called anywhere relevant, even though I'm calling json_tokener_free().

I have tried also using the simple case with just json_tokener_parse(buffer), but the memory leak is still there.

Is there something I'm overlooking? Like an extra step for freeing that I missed in the documentation?

Library version:

pkg-config --print-provides json-c
json-c = 0.12.1

[rgerhards]

did you free (_put) the object the tokener returned?

[mariusor]

I wasn't. Thank you.

Maybe it's not clear enough in the documentation but it wasn't obvious for me that this is the mechanism for cleaning up and freeing resources.