Reassociating Hyper with Mod3 seems to have broken 3l

Your setup

• OS (with version): NixOS unstable (25.05.20241207.22c3f2c)
• Desktop environment:
• xkeyboard-config (or xkb-data) package version: 2.43
• Keyboard setup:
  • Keyboard model: pc104
  • Layouts (with variant, if relevant): 3l
  • Options:

Description of Problem

#440 (closed) seems to have broken 3l layout. This is because (I think) it uses ISO_Level5_Shift:

key <LVL5> {[  ISO_Level5_Shift  ]};
modifier_map Mod3  { <LVL5> };

This seems to only affect some xorg apps, in my case Kitty (terminal emulator) and Emacs. xev seems to report it correcly.

How Reproducible

Steps to Reproduce

1. setxkbmap 3l
2. Open emacs
3. Type any number or cursor command

Actual Results

Emacs complains that H- is not mapped

Expected Results

Should print the number or move the cursor

Additional Info

I have added the following patch:

diff --git i/symbols/pc w/symbols/pc
index 8d224c34..bca1242f 100644
--- i/symbols/pc
+++ w/symbols/pc
@@ -50,7 +50,7 @@ xkb_symbols "pc105" {
     modifier_map Mod4  { <SUPR> };

     key <HYPR> {[  NoSymbol, Hyper_L  ]};
-    modifier_map Mod3  { <HYPR> };
+    modifier_map Mod4  { <HYPR> };
     include "srvr_ctrl(fkey2vt)"

And the previous behavior has been restored