Created attachment 185925 [details]
Generic filetype overlay icon for Open Document Formula files

Steps to reproduce
1. Open or create a OpenDocument Formula file
2. Save the file
3. Repeat above steps but give a password
4. Open Start Center with closing all opened document(s)

While other ODF files overlay shown, this is not the case with formula file. 

The icons are completed (icon-themes/<icon>/res/odf_48_8.(png/svg) and icon-themes/<icon>/sfx2/res/128x128_math_doc-p.(png/svg))

I can see also the variable of odf_48_8.png icon in /core/vcl/inc/bitmaps.hlst, /core/sfx2/inc/bitmaps.hlst and /core/vcl/unx/generic/window/salframe.cxx. While 128x128_math_doc-p can be found at /core/sfx2/inc/bitmaps.hlst but somehow it does not work, the overlay icons are generic one

Expected result:
The overlay icon for ODF file shown

Existing result:
The overlay icon for ODF file are not shown, rather generic one (icon-themes/<icon>/res/mainapp_48_8.(png/svg) and icon-themes/<icon>/res/main128.(png/svg))

Reproduced in:
Version: 7.5.1.2 (X86_64) / LibreOffice Community
Build ID: 50(Build:2)
CPU threads: 8; OS: Linux 5.19; UI render: default; VCL: kf5 (cairo+xcb)
Locale: id-ID (id_ID.UTF-8); UI: en-US
Ubuntu package version: 4:7.5.1~rc2-0ubuntu0.22.04.1~lo1
Calc: threaded

Version: 7.6.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: d887b6a6fa2a572f48498839c5a68791c3196634
CPU threads: 8; OS: Linux 5.19; UI render: default; VCL: kf5 (cairo+xcb)
Locale: id-ID (id_ID.UTF-8); UI: en-US
Calc: threaded