I tried to use the UNICODE sequence registry classes contained in WinSTL.

All works well except the fact that the basic_reg_value::value_sz ()
function return a dirty buffer if the registry value is empty. I debugged
and I realized a strange behavior about RegQueryValueExW () Windows API.
Sometimes, this API fills the buffer with only one NULL instead of two (in
UNICODE there must be two NULL characters to end a string) if the registry
value is empty.
The problem is that the basic_reg_value::value_sz () does not initialize the
buffer to be null terminated before to call the traits_type::reg_query_value
() so the buffer returned is dirty.

The workaround would be to put a buffer[0] = 0 line before the call to traits_type::reg_query_value ()

To test this bug you can simply change the STLSoft\test\winstl\reg_value_sequence_test.cpp file to use the UNICODE classes, compile it, and create a key in the registry with some values of type REG_SZ. You fill some values and you leave empty some others and you should see the bug.

Deigo

Sorry, but I'm not feeling terribly intelligent this morning. (Mind on other
things ...) :)

Any chance you could send (or post) a code snippet showing the problem
and/or your proposed solution?

Cheers

Matthew

"Diego Chanoux" <diego.chanoux@libero.it> wrote in message news:bnremh$1fq6$1@digitaldaemon.com...
> I tried to use the UNICODE sequence registry classes contained in WinSTL.
>
> All works well except the fact that the basic_reg_value::value_sz ()
> function return a dirty buffer if the registry value is empty. I debugged
> and I realized a strange behavior about RegQueryValueExW () Windows API.
> Sometimes, this API fills the buffer with only one NULL instead of two (in
> UNICODE there must be two NULL characters to end a string) if the registry
> value is empty.
> The problem is that the basic_reg_value::value_sz () does not initialize
the
> buffer to be null terminated before to call the
traits_type::reg_query_value
> () so the buffer returned is dirty.
>
> The workaround would be to put a buffer[0] = 0 line before the call to traits_type::reg_query_value ()
>
> To test this bug you can simply change the STLSoft\test\winstl\reg_value_sequence_test.cpp file to use the UNICODE classes, compile it, and create a key in the registry with some values of type REG_SZ. You fill some values and you leave empty some others and you should see the bug.
>
>

I've worked out the problem. It's not what you say, because a terminating null character is appended. The problem is that I mistakenly terminate the null at an index given by the data size, which in Unicode is twice the size it should be. <blush>

I've fixed it now, and it'll appear in the next release.

If you want to patch it yourself, you just need to change the line

            buffer[data_size] = 0;

to

            buffer[data_size / sizeof(char_type)] = 0;


Thanks for spotting it

Matthew

"Diego Chanoux" <diego.chanoux@libero.it> wrote in message news:bnremh$1fq6$1@digitaldaemon.com...
> I tried to use the UNICODE sequence registry classes contained in WinSTL.
>
> All works well except the fact that the basic_reg_value::value_sz ()
> function return a dirty buffer if the registry value is empty. I debugged
> and I realized a strange behavior about RegQueryValueExW () Windows API.
> Sometimes, this API fills the buffer with only one NULL instead of two (in
> UNICODE there must be two NULL characters to end a string) if the registry
> value is empty.
> The problem is that the basic_reg_value::value_sz () does not initialize
the
> buffer to be null terminated before to call the
traits_type::reg_query_value
> () so the buffer returned is dirty.
>
> The workaround would be to put a buffer[0] = 0 line before the call to traits_type::reg_query_value ()
>
> To test this bug you can simply change the STLSoft\test\winstl\reg_value_sequence_test.cpp file to use the UNICODE classes, compile it, and create a key in the registry with some values of type REG_SZ. You fill some values and you leave empty some others and you should see the bug.
>
>

Thanks for your response. I have followed your suggestion and all is ok now.

Diego

"Matthew Wilson" <matthew-hat@-stlsoft-dot.-org> wrote in message news:bnsitk$152$1@digitaldaemon.com...
> I've worked out the problem. It's not what you say, because a terminating null character is appended. The problem is that I mistakenly terminate the null at an index given by the data size, which in Unicode is twice the
size
> it should be. <blush>
>
> I've fixed it now, and it'll appear in the next release.
>
> If you want to patch it yourself, you just need to change the line
>
>             buffer[data_size] = 0;
>
> to
>
>             buffer[data_size / sizeof(char_type)] = 0;
>
>
> Thanks for spotting it
>
> Matthew
>
> "Diego Chanoux" <diego.chanoux@libero.it> wrote in message news:bnremh$1fq6$1@digitaldaemon.com...
> > I tried to use the UNICODE sequence registry classes contained in
WinSTL.
> >
> > All works well except the fact that the basic_reg_value::value_sz () function return a dirty buffer if the registry value is empty. I
debugged
> > and I realized a strange behavior about RegQueryValueExW () Windows API. Sometimes, this API fills the buffer with only one NULL instead of two
(in
> > UNICODE there must be two NULL characters to end a string) if the
registry
> > value is empty.
> > The problem is that the basic_reg_value::value_sz () does not initialize
> the
> > buffer to be null terminated before to call the
> traits_type::reg_query_value
> > () so the buffer returned is dirty.
> >
> > The workaround would be to put a buffer[0] = 0 line before the call to traits_type::reg_query_value ()
> >
> > To test this bug you can simply change the STLSoft\test\winstl\reg_value_sequence_test.cpp file to use the UNICODE classes, compile it, and create a key in the registry with some values
of
> > type REG_SZ. You fill some values and you leave empty some others and
you
> > should see the bug.
> >
> >
>
>

Cool. :)

"Diego Chanoux" <diego.chanoux@libero.it> wrote in message news:bntc6l$1j2r$1@digitaldaemon.com...
> Thanks for your response. I have followed your suggestion and all is ok
now.
>
> Diego
>
> "Matthew Wilson" <matthew-hat@-stlsoft-dot.-org> wrote in message news:bnsitk$152$1@digitaldaemon.com...
> > I've worked out the problem. It's not what you say, because a
terminating
> > null character is appended. The problem is that I mistakenly terminate
the
> > null at an index given by the data size, which in Unicode is twice the
> size
> > it should be. <blush>
> >
> > I've fixed it now, and it'll appear in the next release.
> >
> > If you want to patch it yourself, you just need to change the line
> >
> >             buffer[data_size] = 0;
> >
> > to
> >
> >             buffer[data_size / sizeof(char_type)] = 0;
> >
> >
> > Thanks for spotting it
> >
> > Matthew
> >
> > "Diego Chanoux" <diego.chanoux@libero.it> wrote in message news:bnremh$1fq6$1@digitaldaemon.com...
> > > I tried to use the UNICODE sequence registry classes contained in
> WinSTL.
> > >
> > > All works well except the fact that the basic_reg_value::value_sz () function return a dirty buffer if the registry value is empty. I
> debugged
> > > and I realized a strange behavior about RegQueryValueExW () Windows
API.
> > > Sometimes, this API fills the buffer with only one NULL instead of two
> (in
> > > UNICODE there must be two NULL characters to end a string) if the
> registry
> > > value is empty.
> > > The problem is that the basic_reg_value::value_sz () does not
initialize
> > the
> > > buffer to be null terminated before to call the
> > traits_type::reg_query_value
> > > () so the buffer returned is dirty.
> > >
> > > The workaround would be to put a buffer[0] = 0 line before the call to traits_type::reg_query_value ()
> > >
> > > To test this bug you can simply change the STLSoft\test\winstl\reg_value_sequence_test.cpp file to use the
UNICODE
> > > classes, compile it, and create a key in the registry with some values
> of
> > > type REG_SZ. You fill some values and you leave empty some others and
> you
> > > should see the bug.
> > >
> > >
> >
> >
>
>