[Bug]: Specify two modifiers in map doesn't work

[user202729]

Is there an existing issue for this?

• I have searched the existing issues

Problem

When I type

map <C-S-v> feedkeys ":exec xterm -e /home/user202729/useful-sh/zathura-open-in-vim         $PAGE $FILE"

it gives "Invalid special key value for C-A-v".

Meanwhile <C-V> works.

Steps to reproduce

Expected behavior

Both works.

zathura version (zathura --version)

0.5.8

girara version (zathura --version)

0.4.4

zathura backend

mupdf