Re: [xml] xmlDocDump() on Windows

[Daniel Veillard <veillard redhat com>]

On Fri, Sep 14, 2007 at 08:06:22AM +0200, Trappel Martin wrote:
> Daniel Corbe wrote:
> > /* Begin code snippet */
> > xmlDocPtr mtp3;
> > FILE *xml;
> >
> > mtp3 = xmlReadFile(config->MTP3filename, NULL, 0); xml =
> > fopen(config->MTP3filename, FOPEN_MODE_OVERWRITE); if (!xml ||
> > ferror(xml)) {
> >
> > outputf("ERROR WRITING MTP3 XML File: %s\n", strerror(errno)); } else
> > { xmlDocDump(xml, mtp3); fclose(xml); }
> (...)
> > I've tried building my app on both debug and release, and the same thing happens.
> > You're saying there may be something wrong with my build environment?
> (...)
> >       libxml2-2.6.30 (binary) as gotten from:
> >       http://www.zlatkovic.com/libxml.en.html
>
>
> This cannot work.
> You cannot reliably work with FILE* as a parameter to any dll unless you are 100% sure that it uses 
> _exactly_ the same runtime version.
>
> Now, the prebuilt version of libxml2 links against MSVCRT.dll (as it is built using VC6, afaik)
>
> You however, using VC8, are linking your program against an exact version of MSVCR80?.dll which you can 
> find in the WINDOWS/WinSxS directory.
>
> If you want to use any libxml2 function that relies on runtime lib structures like FILE* you have to 
> compile it yourself against the same msvcr* version as your application.
>
> Personally, I would avoid these functions and use something like xmlDocDumpFormatMemory to write the tree 
> to memory and save that to a file.

  I don't use windows, but from the past discussions, I believe this to
be exact and the problem faced by the person reporting the crash. FILE *
seems to be completely incompatible between versions of runtimes if they
are not 100% the same. To me this is a bug in the ABI garantees of the
Windows compilers and absolutely not a libxml2 problem. 
  Solution is to recompile libxml2 with your compiler and flags or avoid
any API using FILE *.

Daniel

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