[poppler] another problem with saving linearized files

[Hib Eris]

Hi Axel,

Thank you for reporting this issue.

On Thu, Jun 9, 2011 at 6:53 PM, Axel Strübing <axel.struebing at freenet.de> wrote:
> Dear popplers
>
> there seems to be a problem in PDFDoc::writeTrailer.
>
> For incremental updating linearized pdffiles  the result of getStartXRef() is
> written as the "/Prev" entry in the trailer dictionary.
> The value is determined from the offset after the first 'endobj' string in the
> file. In my example this is not the offset of the expected 'xref' keyword.
>
> Unfortunately the parser/lexer in poppler is more tolerant than other ...
> So I have other software that is rejecting the poppler saved files as invalid
> :-(
>
> Could you check if the following change in PDFDoc.cc would do more harm than
> good? It is only used in building the XRef instance.
> ------------ change following lines ------------
>      for (i = 0; i < n; i++) {
>        if (!strncmp("endobj", &buf[i], 6)) {
>           startXRefPos = i+6;
>           break;
>        }
>      }
> ------------ to ------------------------------------
>     for (i = 0; i < n; i++) {
>        if (!strncmp("xref", &buf[i], 4)) {
>          startXRefPos = i;
>          break;
>        }
>     }