[fpc-pascal] possible json parser memory leak

[Michael Van Canneyt]

On Sun, 18 Dec 2011, ik wrote:

> Hello,
> 
> I'm using FPC 2.6 (rc) x86_64 on Linux with JSONParser.
> 
> I've written the following code:
> 
> -----------------------
> uses fpjson, jsonparser, SysUtils, classes;
> 
> var
>   parser    : TJSONParser;
>   json_file : TFileStream; 
> 
> begin
>   json_file := TFileStream.Create('/tmp/test.json', fmOpenRead);
>   json_file.position := 0;
>   parser := TJSONParser.create(json_file);
>   writeln('JSON: ', parser.Parse.AsJSON);

You are not freeing the result of the parse operation ?

The user is responsible for freeing the result of .parse()

So you must do

Var
   D: TJSONData;

    parser := TJSONParser.create(json_file);
    D:=Parser.parse;
    writeln('JSON: ', D.AsJSON);
    D.free; // Free result of parse.

And while you're at it, you must always use try/finally blocks.
Otherwise any exception (an error in the json) will result in 
your code not freeing the file stream or parser instance.

Michael.