Steps to reproduce
1. Create a folder a call it "presentation_test"
2. Create an odp and save it in that folder
3. Find a video, place it in the folder and then drag it into the presentation
4. Save and then reopen the odp. The preview imgae of the video should appear
5. Rename the folder to "presentation test" (replace the underscore with a space)
6. Reopen the odp. The preview of the video won't appear (replaced with grey question mark) but will still play in the presentation.
I'm using Libre Office 6 on Ubuntu 18.04
Repro on Linux, but not on Windows.
Version: 18.104.22.168.alpha0+ (x64)
Build ID: 288878045e54651ffe96e5faa879ab3bbabf9510
CPU threads: 4; OS: Windows 10.0; UI render: default;
TinderBox: Win-x86_64@42, Branch:master, Time: 2018-06-04_23:12:13
Locale: fi-FI (fi_FI); Calc: group threaded
Arch Linux 64-bit
Build ID: 67aaa98600269e6b8fa631146c3649a261369471
CPU threads: 8; OS: Linux 4.16; UI render: default; VCL: kde4;
Locale: fi-FI (fi_FI.UTF-8); Calc: group threaded
Built on June 7th 2018
One manifestation of the problem (not quoting paths): when I was testing another bug, it had a file 'billy elliot.mpeg'. When I inserted it to Impress, I got this in the terminal:
'No src-element named "elliot" - omitting link'