Created attachment 158932 [details]
Example file from Writer

When an OLE object is inserted to a new Writer document and saved as DOCX, Word opens it with an ugly black background.

Steps to reproduce:
1.	Insert – Object – OLE-object, Create from file, select an existing file.
2.	Check “Display as icon” box
3.	Save the file as DOCX and open it in Word

Actual results:
Icon in Word will have an ugly black background.

Expected results:
Transparent background even in Word.

LibreOffice details:
Version: 7.0.0.0.alpha0+ (x64)
Build ID: ec85ed21a960a198a01778cdb89a91fabcb5d0c0
CPU threads: 4; OS: Windows 6.3 Build 9600; UI render: GL; VCL: win; 
Locale: hu-HU (hu_HU); UI-Language: en-US
Calc: CL

Verzió: 6.0.0.3
Build az.: 64a0f66915f38c6217de274f0aa8e15618924765
CPU szálak: 4; OS: Windows 6.3; Felületmegjelenítés: GL; 
Területi beállítások: hu-HU (hu_HU); Calc: CL

Version: 5.1.0.3
Build ID: 5e3e00a007d9b3b6efb6797a8b8e57b51ab1f737
CPU Threads: 4; OS Version: Windows 6.2; UI Render: default; 
Locale: en-US (hu_HU)

Before that only a placeholder image was exported, which looked the same in:
Version: 5.0.0.5
Build ID: 1b1a90865e348b492231e1c451437d7a15bb262b
Locale: hu-HU (hu_HU)

Version: 4.3.0.4
Build ID: 62ad5818884a2fc2e5780dd45466868d41009ec0

But not in:
Verzió: 4.2.0.4
Build az.: 05dceb5d363845f2cf968344d7adab8dcfb2ba71

Verzió: 4.1.0.4
Build az.: 89ea49ddacd9aa532507cbf852f2bb22b1ace28

Until 4.2 PNG images were exported, after that BMP images are.

Bibisected using bibisect-win32-4.3 to: 
URL:https://cgit.freedesktop.org/libreoffice/core/commit/?id=af63727b9fdd48258f692d1ccf6d15daccc18681 
author	Armin Le Grand <alg@apache.org>	2014-02-27 13:46:24 +0000
committer	Caolán McNamara <caolanm@redhat.com>	2014-02-27 19:30:40 +0000
summary: Resolves: #i15508# Added support for BMP file type