Delphi memory leak TJSONTextReader - json

Question

I get memory leaks with TJSONTextReader. I more or less implemented the example from embarcadero. http://docwiki.embarcadero.com/CodeExamples/Tokyo/en/RTL.JSONReader
Is this a bug or am I missing anything?
Content of memoryleak_example.txt
{
"products": [{
"id": "14469654611354654",
"name": "productname_xyz",
"height": 111.550000,
}],
"products_feedback": null
}
This is my example code:
var
streamreader: TStreamReader;
jsonreader: TJSONTextReader;
arrstart, objstart: boolean;
height: double;
id, name: string;
begin
// initialize or compiler warning
arrstart := false;
objstart := false;
height := 0;
streamreader := TStreamReader.Create('C:\temp\memoryleak_example.txt', TEncoding.UTF8);
try
jsonreader := TJSONTextReader.Create(streamreader);
try
while jsonreader.Read do begin
case jsonreader.TokenType of
// product object in products array
TJsonToken.StartObject: if arrstart then objstart := true;
// check for prodcuts array
TJsonToken.StartArray: if (LowerCase(jsonreader.Path) = 'products') then arrstart := true;
TJsonToken.Float:
if objstart then
if jsonreader.Path.EndsWith('height', true) then
height := jsonreader.Value.AsExtended;
TJsonToken.String:
if objstart then begin
if jsonreader.Path.EndsWith('id', true) then
id := jsonreader.Value.AsString;
if jsonreader.Path.EndsWith('name', true) then
name := jsonreader.Value.AsString;
end;
// end product object
TJsonToken.EndObject:
if arrstart and objstart then begin
objstart := false;
if id <> '' then
Memo1.Lines.Add(Format('id: %s - name: %s - height: %g', [id, name, height]));
// reset values
id := '';
name := '';
height := 0;
end;
// end of products array
TJsonToken.EndArray: if (LowerCase(jsonreader.Path) = 'products') then arrstart := false;
end;
end;
finally
jsonreader.Free;
end;
finally
streamreader.Free;
end;
end;
This is the memory leak report on shutdown:
---------------------------
Unexpected Memory Leak
---------------------------
An unexpected memory leak has occurred. The unexpected small block leaks are:
1 - 12 bytes: Unknown x 6
13 - 20 bytes: UnicodeString x 1
21 - 28 bytes: UnicodeString x 2, Unknown x 1
29 - 36 bytes: UnicodeString x 1
45 - 52 bytes: TList<System.JSON.Types.TJsonPosition> x 6
85 - 92 bytes: Unknown x 5
---------------------------
OK
---------------------------
I use Delphi Seattle.
Embarcadero RAD Studio 10 Seattle Version 23.0.21418.4207
I found this discussion:
https://forums.embarcadero.com/thread.jspa?threadID=118014
I don't know if this is related.
--------------------------------2018/7/13 11:48:16--------------------------------
A memory block has been leaked. The size is: 12
This block was allocated by thread 0x18B0, and the stack trace (return addresses) at the time was:
41CA186 [System][System.#GetMem]
4241E94 [System.Generics.Defaults][System.Generics.Defaults.MakeInstance]
424256A [System.Generics.Defaults][System.Generics.Defaults.Comparer_Selector_Binary]
4242E84 [System.Generics.Defaults][System.Generics.Defaults._LookupVtableInfo]
EED8629 [System.JSON.Types][System.JSON][System.JSON.Types.{System.Generics.Defaults}TComparer<System.JSON.Types.TJsonPosition>.Default]
EEE1572 [System.JSON.Readers][System.JSON][System.JSON.Readers.{System.Generics.Collections}TList<System.JSON.Types.TJsonPosition>.Create]
EEDB91E [System.JSON.Readers][System.JSON][System.JSON.Readers.TJsonReader.GetPath]
The block is currently used for an object of class: Unknown
The allocation number is: 3192748
Current memory dump of 256 bytes starting at pointer address 79DC9440:
7C EF A0 04 01 00 00 00 10 00 00 00 FE C5 93 13 00 00 00 00 A0 93 DC 79 00 00 00 00 00 00 00 00
60 74 1E 04 00 00 00 00 B9 B7 30 00 86 A1 1C 04 94 1E 24 04 6A 25 24 04 84 2E 24 04 29 86 ED 0E
72 15 EE 0E 1E B9 ED 0E AD 16 EF 0E CC 0C EF 0E 73 54 EF 0E 04 81 20 04 B0 18 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 0C 00 00 00 00 00 00 00 DE 3A 6C EC 7C EF A0 04 01 00 00 00
10 00 00 00 21 C5 93 13 00 00 00 00 A0 93 DC 79 00 00 00 00 00 00 00 00 60 74 1E 04 00 00 00 00
C6 B7 30 00 86 A1 1C 04 94 1E 24 04 6A 25 24 04 84 2E 24 04 29 86 ED 0E 72 15 EE 0E 1E B9 ED 0E
E5 16 EF 0E CC 0C EF 0E 73 54 EF 0E 04 81 20 04 B0 18 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Answer 1

Thank you Dalija Prasnikar.
I took the System.JSON.Readers.pas source of Tokyo and the memory leak is gone.
try
Result := TJsonPosition.BuildPath(Positions);
finally
if Positions <> FStack then
Positions.Free;
end;
This was missing in the function TJsonReader.GetPath: string; method.