Potential memoryleak in pptmplat unit with FModifiedNames TStringlist

rbuser

Hi

I am getting some memory leaks in the RB7 pptmplat unit with the Freeing of
FModifiedNames (TStringList) instances.. There is no logic present either
in the TppTemplate.Destroy method nor in the TppTemplate.LoadFromStream
procedure to clean up any objects which might off been assigned to the
FModifiedNames object.

Anybody else found this problem? Or am i missing something?
I guess i have to change the logic myself?
What is the procedure for logging bugs with Report Builder 7 source.??

Thanks

nardmoseley

The FModifiedNames TStringList object is created in the the
TppTemplate.LoadFromStream and destroyed in the try..finally block in that
same method. The purpose of the StringList is to track object references
that are renamed during the report template process. The objects stored to
the FModifiedNames list are used as references to the report objects.
FModifiedNames should not free the object - those objects are part of the
report layout that is loaded.

There are no known memory leaks in ReportBuilder 7.04. However, if you think
you have found a new leak, please create a simple example project using
standard Delphi components and ReportBuilder. Email in zip format to
support@digital-metaphors.com and we can check it out here.



--
Nard Moseley
Digital Metaphors Corporation
http://www.digital-metaphors.com

rbuser

Thanks for the reply..

I agree that should NOT free the objects as they report components but the
code should setting the object references in the FModifiedNames to nil
before freeing
FModifiedNames itself and it appears it is not causing my memory manager to
report the leaks.

Below is a the actual RB7 code but only with the relevant code in it related
to the problem. I have added some comments to describe the problem

procedure TppTemplate.LoadFromStream(aStream: TStream);
// Some vars
begin
// some other lines before
FModifiedNames := TStringList.Create;
//// So FModifiedNames is not freed if Loadstart = false
if not LoadStart then Exit;
try
// Some other code
finally
// some other lines
// Code i have added to my Report builder 7.04 ppTmplat unit)

if Assigned (FModifiedNames) then
For X := 0 to FModifiedNames.Count-1 do
FModifiedNames.Objects[X] := nil;

// End of my code changes

FModifiedNames.Free;
FModifiedNames := nil;
end

As you can tell it means that FModifiedNames does not get freed if Loadstart
= False which also causes a memory leak as the detroy method of TppTemplate
does not seem to clean up a rogue FModifiedNames instance.

Of course this observation is based on my 7.04 version of the ppTmplat
unit..

Thanks again for your time and reply..

Edwin

nardmoseley

Sorry for not responding sooner. Thanks for pointing that out the flaw.
Looks like the code needs to modified so that the ModifiedNames object is
created after the Exit code.

example:

if not LoadStart then Exit;

FModifiedNames := TStringList.Create;

We will create a patch source file that contains this change and will
incorporate it into the future code base....




--
Nard Moseley
Digital Metaphors Corporation
www.digital-metaphors.com