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 : [e-mail]; 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 : [e-mail]; 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
>
> Ros-dev mailing list
> [e-mail]
> http://www.reactos.org/mailman/listinfo/ros-dev