Make check for complete type more explicit

When 485c9d4f0e59e13e772da8f8a7975f0ddd77c33e "Clarify the use of
untools::WeakReference" introduced cppu::detail::isUnoInterfaceType and its use
in the requires-clause of unotools::WeakReference::get, its commit message
argued that while isUnoInterfaceType only works if the given type is complete,
that would already be taken care of via the use of std::is_convertible_v in the
implementation of unotools::WeakReference::get.  But while std::is_convertible_v
nominally requires its argument types to be complete (unless they are void, or
arrays of unknown bound), typical implementations like recent libc++ or
libstdc++ do not seem to enforce that (and just return false in such a case).

So better make isUnoInterfaceType explicitly require that the given type is
complete.  Which turned up one case where it isn't at the point where
unotools::WeakReference<SdrTextObj>::get is called.  (And while the resulting
call to dynamic_cast<SdrTextObj*>(...) in the implementation of that function
would cause an error when SdrTextObj is not complete, compilers happened to
instantiate that template specialization only at the end of the TU, by which
time SdrTextObj happened to be a complete type in the TUs including that
sd/source/ui/inc/futext.hxx.  So all happened to work out OK.)

Change-Id: I704b8b437fa836e290245d1727e4d356128ef63c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/143667
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

0 files changed, 0 insertions, 0 deletions