[Lazarus] Is this a bug?

[Wolf]

Thanks, Mattias and Joost,
now I understand the real bug is in my assumptions on what goes on 
behind the screens. But that leads to another question: is there any 
documentation where I can read up on this so that I may improve on my 
programming, and particular debugging, skills?
wolf

On 16/06/17 23:27, Mattias Gaertner via Lazarus wrote:
> On Fri, 16 Jun 2017 21:43:38 +1200
> Wolf via Lazarus <lazarus at lists.lazarus-ide.org> wrote:
>
>> If I understand you correctly, because
>> 1. command line parameters are internally treated as a null-terminated
>> string (i.e. AnsiString), a call to ParamStr() implies a heap allocation
>> and thus,
>> 2. since ParamStr() is handled by the system unit, a call to halt will
>> result in a memory leak because Heaptrc is not aware of this allocation.
> No, that's not how temporary strings work.
>
> Just move the code in front of your halt into a separate procedure and
> the mem leaks are gone.
>
> The compiler creates an implicit try..finally to free managed types
> and since Halt skips the finally parts the strings are not freed.
>
>   
>> If this is correct, then the conclusion has to be that Heaptrc cannot be
>> trusted as a debugging tool because it is ill-informed about what the
>> system unit is up to.
> Nonsense. This is neither specific to the system unit nor heaptrc.
> The conclusion is that must not use Halt, when you need try..finally.
>
>
> Mattias