[OPEN-ILS-DEV] osrf_json_parser.c: memory leak when handling error

[Bill Erickson]

Scott McKellar wrote:
> In _jsonInsertParserItem(), we receive a pointer to a jsonObject named
> newo.  Normally, newo is incorporated into the object that the parser
> is building.  Whoever receives the object built by the parser is
> responsible for freeing it.
>
> However: if the sub-object currently being processed by the parser is
> neither a hash nor an array, the default branch of the switch/case 
> structure merely writes a message to stderr, without incorporating
> newo into the growing jsonObject.
>
> My first impulse was to add a line to the default branch, to free 
> newo.  Then I noticed that, after the switch/case, we reference newo
> again.  So we don't want to free it as I had first thought.
>
> The end result, if this situation ever occurs, is that we leak newo.
> We may hang on to it for a while as the current object, but since 
> we don't incorporate it into the object wo're building, we
> eventually lose it.
>
> Presumably this situation never arises in practice, or happens so
> rarely that the memory leak isn't worth worrying about.  For all I
> know it may be impossibe for this situation to arise at all, even 
> for arbitrarily mangled JSON input text.  I haven't tried to unravel
> all the logic.
>
> However the handling of this situation looks like leftover debugging
> code rather than proper error reporting.  At a minimum we should use
> the usual logging functions instead of writing directly to stderr.
> In addition, I'm not sure that it's appropriate to point p->current
> to newo in this situation.  I'd submit a patch, but I don't trust
> myself to guess what the right response is.
>
>   

Yep, that's old debugging code.  The switch in _jsonInsertParserItem() 
should probably be changed to an if/else (
JSON_HASH vs. JSON_ARRAY).  There's no other way to reach that chunk of 
code.

-bill

-- 
Bill Erickson
| VP, Software Development & Integration
| Equinox Software, Inc. / The Evergreen Experts
| phone: 877-OPEN-ILS (673-6457)
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