From 8c51850839f34074785a857da0968234eb92f421 Mon Sep 17 00:00:00 2001
From: Anish Pallati <i@anish.land>
Date: Mon, 22 Jun 2026 16:18:52 -0400
Subject: [PATCH] fix(input): don't send ALT when right-alt is remapped to meta

Signed-off-by: Anish Pallati <i@anish.land>
---
 src/config.cpp |  6 +++---
 src/config.h   |  1 +
 src/input.cpp  | 22 +++++++++++++++++++---
 3 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/src/config.cpp b/src/config.cpp
index 6d266c0ef22..1c8bed32b47 100644
--- a/src/config.cpp
+++ b/src/config.cpp
@@ -1274,10 +1274,10 @@ namespace config {
 
     // This config option will only be used by the UI
     // When editing in the config file itself, use "keybindings"
-    bool map_rightalt_to_win = false;
-    bool_f(vars, "key_rightalt_to_key_win", map_rightalt_to_win);
+    input.key_rightalt_to_key_win = false;
+    bool_f(vars, "key_rightalt_to_key_win", input.key_rightalt_to_key_win);
 
-    if (map_rightalt_to_win) {
+    if (input.key_rightalt_to_key_win) {
       input.keybindings.emplace(0xA5, 0x5B);
     }
 
diff --git a/src/config.h b/src/config.h
index e0e40501d0b..f074de579c8 100644
--- a/src/config.h
+++ b/src/config.h
@@ -217,6 +217,7 @@ namespace config {
     bool ds5_inputtino_randomize_mac;
 
     bool keyboard;
+    bool key_rightalt_to_key_win;
     bool mouse;
     bool controller;
 
diff --git a/src/input.cpp b/src/input.cpp
index db7618bfb05..d01b4f149f6 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -178,6 +178,9 @@ namespace input {
     // Keep track of alt+ctrl+shift key combo
     int shortcutFlags;
 
+    bool left_alt_pressed = false;
+    bool right_alt_pressed = false;
+
     std::vector<gamepad_t> gamepads;
     std::unique_ptr<platf::client_input_t> client_context;
 
@@ -760,17 +763,30 @@ namespace input {
     auto release = util::endian::little(packet->header.magic) == KEY_UP_EVENT_MAGIC;
     auto keyCode = packet->keyCode & 0x00FF;
 
+    if (keyCode == VKEY_LMENU) {
+      input->left_alt_pressed = !release;
+    } else if (keyCode == VKEY_RMENU) {
+      input->right_alt_pressed = !release;
+    }
+
+    // Right-alt maps to meta, so it must not also register as ALT
+    int modifiers = packet->modifiers;
+    if (config::input.key_rightalt_to_key_win &&
+        input->right_alt_pressed && !input->left_alt_pressed) {
+      modifiers &= ~MODIFIER_ALT;
+    }
+
     // Set synthetic modifier flags if the keyboard packet is requesting modifier
     // keys that are not current pressed.
     uint8_t synthetic_modifiers = 0;
     if (!release && !is_modifier(keyCode)) {
-      if (!(input->shortcutFlags & input_t::SHIFT) && (packet->modifiers & MODIFIER_SHIFT)) {
+      if (!(input->shortcutFlags & input_t::SHIFT) && (modifiers & MODIFIER_SHIFT)) {
         synthetic_modifiers |= MODIFIER_SHIFT;
       }
-      if (!(input->shortcutFlags & input_t::CTRL) && (packet->modifiers & MODIFIER_CTRL)) {
+      if (!(input->shortcutFlags & input_t::CTRL) && (modifiers & MODIFIER_CTRL)) {
         synthetic_modifiers |= MODIFIER_CTRL;
       }
-      if (!(input->shortcutFlags & input_t::ALT) && (packet->modifiers & MODIFIER_ALT)) {
+      if (!(input->shortcutFlags & input_t::ALT) && (modifiers & MODIFIER_ALT)) {
         synthetic_modifiers |= MODIFIER_ALT;
       }
     }