kicad-developers team mailing list archive

[Henner Zeller <h.zeller@xxxxxxx>]

On 4 December 2015 at 07:17, jp charras <jp.charras@xxxxxxxxxx> wrote:
> Le 04/12/2015 14:54, Wayne Stambaugh a écrit :
>> Thanks Henner.  I'll take a look at it when I get a chance.  I'm sure
>> this isn't the only place this pattern is used.  If you have a patch,
>> please submit it.
>>
>> Thanks,
>>
>> Wayne
>>
>> On 12/3/2015 3:46 AM, Henner Zeller wrote:
>>> Hi,
>>> Playing with the spectra import/export, I encountered a bug: in that
>>> code are constructs such as
>>>
>>>    ThrowIOError( _("some formatting %s"), GetChars( someWxString ));
>>>
>>> They are ultimately dealt with wxString::PrintfV( fmt, args );
>>>
>>> The output, however, is not as expected. A someWxString with "REF**"
>>> was only displayed as "R". Changing the GetChars() to TO_UTF8() works.
>>>
>>> I suspect that whatever is returned by GetChars() is not properly
>>> passed through the var-args argument, while the simple const char* of
>>> TO_UTF8() does work. I am not sure though if that is the 'right'
>>> solution as this might be different on Windows ? So I'll leave this to
>>> someone more knowledgeable in wxString quirks on different platforms
>
> @Henner,
>
> GetChars is a macro (defined in macros.h)
> It returns a wxChar*, which is the right type here.
>
> (GetChars was written to be equivalent to GetData(), during the time
> GetData(), needed when using wxString::Print(), was removed from
> wxWidgets, in a few 2.9.x versions)
>
> - How to reproduce this issue (it can be different on Linux and on Windows)?

I don't have access to a windows machine to test, but I created a
simplified code in
   https://gist.github.com/hzeller/e377cc8be916b191d499
so that it can be tested and re-produced by others.

This is the output:
$ g++ -Wall -o format-test -isystem
/usr/lib/x86_64-linux-gnu/wx/include/gtk2-unicode-3.0 -isystem
/usr/include/wx-3.0 -D__WXGTK__ format-test.cpp
-L/usr/lib/x86_64-linux-gnu/ -lwx_baseu-3.0 && ./format-test
Input: format:'this is a test >%s<' and value:'SomeTest value'
sizeof(wxChar) = 4
wxstring::PrintfV(fmt, GetChars())  : 'this is a test >S<'
wxstring::PrintfV(fmt, value.GetData())  : 'this is a test >'
wxstring::PrintfV(fmt, TO_UTF8())   : 'this is a test >SomeTest value<'
wxstring::Printf(fmt, wxstring)     : 'this is a test >SomeTest value<'
wxstring::Printf(fmt, GetChars(...)): 'this is a test >SomeTest value<'
wxstring::Printf(fmt, TO_UTF8(..))  : 'this is a test >SomeTest value<'

So findings
  - using the PrintfV() with TO_UTF8() works (on my machine).
  - GetChars() only prints the first character, then stops (I presume
because that points to a multi-byte string, which has \0 every other
character but then is interpreted as const char* ?)
  - GetData() is worse.
  - wxstring::Printf() seems to work with whatever is thrown at it.

> - What happens if you replace GetChars( someWxString ) by
> someWxString.GetData()?

Second output above: it totally messes up the output.

(this is on debian testing with wx 3.0)

-h
>
> --
> Jean-Pierre CHARRAS
>
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