Description:
Trying to create a gallery new theme with svg files. After [Find Files] complete the list, and pressing [All Files] button, files are lost and new theme is not created. The problem repeat for writer, draw and impress.

Steps to Reproduce:
For testing:
1.Download the ClipArt with SVG files
2.Extract files to Directory
3.Open LibreOffice Draw (or writer, or Impress)
4.Following the documentation to create a new theme
4.1 Insert Gallery
4.2 New
4.3 Properties Dialog/Files
4.4 Press [Find Files] Button
4.5 Select the directory with svg files
4.6 Click button [Add All]
4.7 The list of files is lost


Actual Results:
.sdg and .thm files are not created.

Expected Results:
a file .sdg should be created at user .libreoffice directory.


Reproducible: Always


User Profile Reset: Yes

Additional Info:
[Information automatically included from LibreOffice]
Locale: en-US
Module: PresentationDocument
[Information guessed from browser]
OS: Linux (All)
OS is 64bit: yes