From 86bf5698ecfdbe783135ffaf72972a8c562c0fdf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Camilla=20L=C3=B6wy?= <elmindreda@elmindreda.org>
Date: Wed, 13 Dec 2023 15:27:30 +0100
Subject: [PATCH] Fix glfwGetKeyName incorrectly emitting error

glfwGetKeyName emitted GLFW_INVALID_VALUE when passed GLFW_KEY_UNKNOWN
and any scancode not associated with a key token on that platform.

This causes physical keys with no associated key token to emit
GLFW_INVALID_VALUE when the key and scancode are passed directly from
the key event to glfwGetKeyName.  This breaks the promise made in the
reference documentation for glfwGetKeyName.

This commit removes that error for the whole range of valid scancodes.

Fixes #1785
---
 src/cocoa_window.m | 5 +++--
 src/win32_window.c | 9 ++++++---
 src/wl_window.c    | 6 ++++--
 src/x11_window.c   | 6 ++++--
 4 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/src/cocoa_window.m b/src/cocoa_window.m
index 9d794940..c865c09e 100644
--- a/src/cocoa_window.m
+++ b/src/cocoa_window.m
@@ -1659,14 +1659,15 @@ const char* _glfwGetScancodeNameCocoa(int scancode)
 {
     @autoreleasepool {
 
-    if (scancode < 0 || scancode > 0xff ||
-        _glfw.ns.keycodes[scancode] == GLFW_KEY_UNKNOWN)
+    if (scancode < 0 || scancode > 0xff)
     {
         _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode %i", scancode);
         return NULL;
     }
 
     const int key = _glfw.ns.keycodes[scancode];
+    if (key == GLFW_KEY_UNKNOWN)
+        return NULL;
 
     UInt32 deadKeyState = 0;
     UniChar characters[4];
diff --git a/src/win32_window.c b/src/win32_window.c
index db3bed6e..917a0f6c 100644
--- a/src/win32_window.c
+++ b/src/win32_window.c
@@ -2223,14 +2223,17 @@ void _glfwSetCursorModeWin32(_GLFWwindow* window, int mode)
 
 const char* _glfwGetScancodeNameWin32(int scancode)
 {
-    if (scancode < 0 || scancode > (KF_EXTENDED | 0xff) ||
-        _glfw.win32.keycodes[scancode] == GLFW_KEY_UNKNOWN)
+    if (scancode < 0 || scancode > (KF_EXTENDED | 0xff))
     {
         _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode %i", scancode);
         return NULL;
     }
 
-    return _glfw.win32.keynames[_glfw.win32.keycodes[scancode]];
+    const int key = _glfw.win32.keycodes[scancode];
+    if (key == GLFW_KEY_UNKNOWN)
+        return NULL;
+
+    return _glfw.win32.keynames[key];
 }
 
 int _glfwGetKeyScancodeWin32(int key)
diff --git a/src/wl_window.c b/src/wl_window.c
index 8d8f8ab1..f047f44c 100644
--- a/src/wl_window.c
+++ b/src/wl_window.c
@@ -2535,8 +2535,7 @@ void _glfwSetCursorModeWayland(_GLFWwindow* window, int mode)
 
 const char* _glfwGetScancodeNameWayland(int scancode)
 {
-    if (scancode < 0 || scancode > 255 ||
-        _glfw.wl.keycodes[scancode] == GLFW_KEY_UNKNOWN)
+    if (scancode < 0 || scancode > 255)
     {
         _glfwInputError(GLFW_INVALID_VALUE,
                         "Wayland: Invalid scancode %i",
@@ -2545,6 +2544,9 @@ const char* _glfwGetScancodeNameWayland(int scancode)
     }
 
     const int key = _glfw.wl.keycodes[scancode];
+    if (key == GLFW_KEY_UNKNOWN)
+        return NULL;
+
     const xkb_keycode_t keycode = scancode + 8;
     const xkb_layout_index_t layout =
         xkb_state_key_get_layout(_glfw.wl.xkb.state, keycode);
diff --git a/src/x11_window.c b/src/x11_window.c
index 3c76d3a9..c2541b9f 100644
--- a/src/x11_window.c
+++ b/src/x11_window.c
@@ -2901,14 +2901,16 @@ const char* _glfwGetScancodeNameX11(int scancode)
     if (!_glfw.x11.xkb.available)
         return NULL;
 
-    if (scancode < 0 || scancode > 0xff ||
-        _glfw.x11.keycodes[scancode] == GLFW_KEY_UNKNOWN)
+    if (scancode < 0 || scancode > 0xff)
     {
         _glfwInputError(GLFW_INVALID_VALUE, "Invalid scancode %i", scancode);
         return NULL;
     }
 
     const int key = _glfw.x11.keycodes[scancode];
+    if (key == GLFW_KEY_UNKNOWN)
+        return NULL;
+
     const KeySym keysym = XkbKeycodeToKeysym(_glfw.x11.display,
                                              scancode, _glfw.x11.xkb.group, 0);
     if (keysym == NoSymbol)