Re: [ros-dev] [ros-diffs] 01/01: [USERSRV] HardError: Fix compilation warning; fix few comments; fix the default empty window title string.

[Hermès BÉLUSCA-MAÏTO]

This change (on my own code snippet btw, see commit 5a1a35ca5a6) was necessary because
otherwise, the StringPrintf call that is done below (which would then use a
WindowTitleU.Buffer == NULL) would generate the harderror dialog title: "(null)"
(in addition to other strings being appended), instead of just an empty string.
And so the bug is that I forgot to adjust the condition that needs to be checked before
freeing the window title string (if it has been allocated).

Hermès

>   -----Message d'origine-----
>  De : Thomas Faber [mailto:[e-mail]]
>  Envoyé : samedi 9 juin 2018 09:21
>  À : ros-dev(a)reactos.org; Hermès Bélusca-Maïto
>  Objet : Re: [ros-diffs] 01/01: [USERSRV] HardError: Fix compilation warning;
>  fix few comments; fix the default empty window title string.
>  
>  On 2018-04-08 16:17, Hermès Bélusca-Maïto wrote:
> >         /* Retrieve the window title of the client,
> > if it has one */
> >  -    RtlInitEmptyUnicodeString(&WindowTitleU, NULL, 0);
> >  +    RtlInitEmptyUnicodeString(&WindowTitleU, L"", 0); 
>  
>  This looks like a bug. Can you explain why you think it's necessary please?
>  
>  In particular, it will break this:
>  
>  if (WindowTitleU.Buffer) RtlFreeUnicodeString(&WindowTitleU);
>  
>  
>  Thanks,
>  Thomas

[Thomas Faber]

A UNICODE_STRING with Length==0 is an empty string, the value of Buffer
is irrelevant.
If

RtlInitEmptyUnicodeString(&EmptyString, NULL, 0);
printf("%wZ", &EmptyString);

prints "(null)", then that's a bug in printf.
This special-casing with L"" is highly irregular and should be avoided.


On 2018-06-09 14:37, Hermès BÉLUSCA-MAÏTO wrote:
>   This change (on my own code snippet btw, see commit
> 5a1a35ca5a6) was necessary because otherwise, the StringPrintf call that is done below
> (which would then use a WindowTitleU.Buffer == NULL) would generate the harderror dialog
> title: "(null)" (in addition to other strings being appended), instead of just
> an empty string.
>  And so the bug is that I forgot to adjust the condition that needs to be checked before
> freeing the window title string (if it has been allocated).
>  
>  Hermès
>  
> >   -----Message d'origine-----
> >  De : Thomas Faber [mailto:[e-mail]]
> >  Envoyé : samedi 9 juin 2018 09:21
> >  À : ros-dev(a)reactos.org; Hermès Bélusca-Maïto
> >  Objet : Re: [ros-diffs] 01/01: [USERSRV] HardError: Fix compilation warning;
> >  fix few comments; fix the default empty window title string.
> >
> >  On 2018-04-08 16:17, Hermès Bélusca-Maïto wrote:
> > >          /* Retrieve the window title of the
> > > client, if it has one */
> > >  -    RtlInitEmptyUnicodeString(&WindowTitleU, NULL, 0);
> > >  +    RtlInitEmptyUnicodeString(&WindowTitleU, L"", 0); 
> >  This looks like a bug. Can you explain why you think it's necessary please?
> >
> >  In particular, it will break this:
> >
> >  if (WindowTitleU.Buffer) RtlFreeUnicodeString(&WindowTitleU);
> >
> >
> >  Thanks,
> >  Thomas 
>  
>  
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