From 71f0fc59bef7a37b55c7e1c10b1b21b8a86475b7 Mon Sep 17 00:00:00 2001
From: Nick Brassel <nick@tzarc.org>
Date: Sat, 8 Jul 2023 00:59:28 +1000
Subject: [PATCH] Revert "bootmagic mods covering the case when swapped mods
 are pressed at the same time (#21320)" (#21471)

---
 quantum/keycode_config.c | 44 ++++++++++++++++++++++------------------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/quantum/keycode_config.c b/quantum/keycode_config.c
index 864488a65c97..9dd7097c861a 100644
--- a/quantum/keycode_config.c
+++ b/quantum/keycode_config.c
@@ -122,36 +122,40 @@ __attribute__((weak)) uint16_t keycode_config(uint16_t keycode) {
  */
 
 __attribute__((weak)) uint8_t mod_config(uint8_t mod) {
-    /**
-     * Note: This function is for the 5-bit packed mods, NOT the full 8-bit mods.
-     * More info about the mods can be seen in modifiers.h.
-     */
     if (keymap_config.swap_lalt_lgui) {
-        /** If both modifiers pressed or neither pressed, do nothing
-         * Otherwise swap the values
-         * Note: The left mods are ANDed with the right-hand values to check
-         * if they were pressed with the right hand bit set
-         */
-        if (((mod & MOD_RALT) == MOD_LALT) ^ ((mod & MOD_RGUI) == MOD_LGUI)) {
-            mod ^= (MOD_LALT | MOD_LGUI);
+        if ((mod & MOD_RGUI) == MOD_LGUI) {
+            mod &= ~MOD_LGUI;
+            mod |= MOD_LALT;
+        } else if ((mod & MOD_RALT) == MOD_LALT) {
+            mod &= ~MOD_LALT;
+            mod |= MOD_LGUI;
         }
     }
     if (keymap_config.swap_ralt_rgui) {
-        if (((mod & MOD_RALT) == MOD_RALT) ^ ((mod & MOD_RGUI) == MOD_RGUI)) {
-            /* lefthand values to preserve the right hand bit */
-            mod ^= (MOD_LALT | MOD_LGUI);
+        if ((mod & MOD_RGUI) == MOD_RGUI) {
+            mod &= ~MOD_RGUI;
+            mod |= MOD_RALT;
+        } else if ((mod & MOD_RALT) == MOD_RALT) {
+            mod &= ~MOD_RALT;
+            mod |= MOD_RGUI;
         }
     }
     if (keymap_config.swap_lctl_lgui) {
-        /* left mods ANDed with right-hand values to check for right hand bit */
-        if (((mod & MOD_RCTL) == MOD_LCTL) ^ ((mod & MOD_RGUI) == MOD_LGUI)) {
-            mod ^= (MOD_LCTL | MOD_LGUI);
+        if ((mod & MOD_RGUI) == MOD_LGUI) {
+            mod &= ~MOD_LGUI;
+            mod |= MOD_LCTL;
+        } else if ((mod & MOD_RCTL) == MOD_LCTL) {
+            mod &= ~MOD_LCTL;
+            mod |= MOD_LGUI;
         }
     }
     if (keymap_config.swap_rctl_rgui) {
-        if (((mod & MOD_RCTL) == MOD_RCTL) ^ ((mod & MOD_RGUI) == MOD_RGUI)) {
-            /* lefthand values to preserve the right hand bit */
-            mod ^= (MOD_LCTL | MOD_LGUI);
+        if ((mod & MOD_RGUI) == MOD_RGUI) {
+            mod &= ~MOD_RGUI;
+            mod |= MOD_RCTL;
+        } else if ((mod & MOD_RCTL) == MOD_RCTL) {
+            mod &= ~MOD_RCTL;
+            mod |= MOD_RGUI;
         }
     }
     if (keymap_config.no_gui) {