Linker error when compiling libreoffice core.

[Caolán McNamara]

On Tue, 2021-09-07 at 16:41 +0200, Mysaa Java wrote:
> /sources/libreoffice/ext/core/workdir/CxxObject/writerfilter/source/rtf
> tok/rtfdocumentimpl.o: in function
> `writerfilter::rtftok::RTFDocumentImpl::handleEmbeddedObject()':
> rtfdocumentimpl.cxx:(.text+0x86bc): undefined reference to `non-virtual
> thunk to cppu::ImplInheritanceHelper<utl::OInputStreamWrapper,
> com::sun::star::io::XSeekable>::acquire()'
> collect2: error: ld returned 1 exit status
> make: ***
> [/sources/libreoffice/ext/core/writerfilter/Library_writerfilter.mk:10:
> /sources/libreoffice/ext/core/instdir/program/libwriterfilterlo.so]
> Error 1
> ```

I haven't had this exact error before, but we have seen similar in the
past. What's probably relevant is the version of your compiler
(gcc --version). The last time we saw this the workaround deployed was
https://cgit.freedesktop.org/libreoffice/core/commit/?id=c820cb429fc3d3eec9bf6596f0a34995cbd93982

Trying similar for OSeekableInputStreamWrapper might help.

> Steps to Reproduce:
> 1. clone the core repository of libreoffice
> 2. Autogen: ./autogen.sh --without-system-libxml --with-
> distro=LibreOfficeOnline
> 3. Make: make

As an aside, I don't think the linker error is due to the configure
flags used here, but --with-distro=LibreOfficeOnline is an unusual
config choice to pick (and it already includes --without-system-libxml)
and will result in a libreoffice build that doesn't have a gui so if it
does build launching it won't give you something you can interact with.