Created attachment 153449 [details]
Sample DOCX with embedded Visio object
Attached DOCX contains a simple Visio drawing (inside the zip it's word\embeddings\Microsoft_Visio_Drawing1.vsdx). When opened in Word and clicking on the object, it clearly behaves as an embedded object (upon double-clicking it'll complain if Visio isn't installed, that's expected).
- Open and save it in Writer, then reopen in Word.
=> The object appears as a picture in Word (Picture tools ribbon shows on toolbar).
The visio file is still there, but now it's word\embeddings\oleObject1.bin.
Observed using LO 22.214.171.124.alpha0+ (d3d13140f0036c53aa74820b41acfeffa3572168), 126.96.36.199 / Windows 7.
In 188.8.131.52 even the embedded file gets lost.
I think a good place to start is going to be reviewing https://cgit.freedesktop.org/libreoffice/core/commit/?id=d60398ff5b42ff77a4002dcd13b7fb8c9a73eade
+// TODO: this is probably a sub-optimal approach: ideally the media type
+// of the stream from [Content_Types].xml should be stored somewhere for this
+// purpose, but currently the media type of all OLE streams in the storage is
+// just "application/vnd.sun.star.oleobject"