But LibreOffice is NOT licenced under the LGPL !!! If you want, you can - !legally! - ignore the (L)GPL entirely!
ALL LibreOffice code (that is, code donated to the LibreOffice project) is licenced MPL. Add the fact that the original code base has been relicenced to Apache by Oracle, and (murkiness aside) you can now legally copy the entire LibreOffice project without using the (L)GPL for as much as one line of code!
The choice of MPL by TDF was apparently deliberate to be friendly to IBM.