Created attachment 115334 [details]
The attached bugdoc contains an embedded OLE object (PDF file). In the document, the embedded OLE object is displayed as an icon, which is EMF. The background of the bitmap should be white/transparent, but it is black in LibreOffice 4.1 and higher. The icon is not displayed at all in earlier LibreOffice versions, so it is probably not a regression.
The EMF file contains EMR_ALPHABLEND record (AlphaBlend GDI call), and I think the problem is that transparency is not handled by LibreOffice's bitmap processing code.
Bug 90539 was similar, but there was possible to use a hack.
Created attachment 115335 [details]
screenshot Word vs. LibreOffice
Win 7 Pro 64-bit Version: 126.96.36.199.alpha1+ (x64)
Build ID: 98436c4b53639d86f261ac630c46d32e3c7b8e28
TinderBox: Win-x86_64@42, Branch:master, Time: 2015-05-04_00:07:10
Locale: fi-FI (fi_FI)
*** This bug has been marked as a duplicate of bug 91017 ***