CVE-2019-9855: Windows 8.3 path equivalence handling flaw allows LibreLogo script execution

LibreOffice is typically bundled with LibreLogo, a programmable turtle vector graphics script, which can execute arbitrary python commands contained with the document it is launched from. LibreOffice also has a feature where documents can specify that pre-installed scripts can be executed on various document script events such as mouse-over, etc. Protection was added to block calling LibreLogo from script event handers. However a Windows 8.3 path equivalence handling flaw left LibreOffice vulnerable under Windows that a document could trigger executing LibreLogo via a Windows filename pseudonym. This issue affects: Document Foundation LibreOffice 6.2 versions prior to 6.2.7; 6.3 versions prior to 6.3.1.