Pass scancode with synthetic key release events

README.md

@@ -120,6 +120,7 @@ information on what to include when reporting a bug.
 - Bugfix: `glfwGetInstanceProcAddress` returned `NULL` for
           `vkGetInstanceProcAddr` when `_GLFW_VULKAN_STATIC` was enabled
 - Bugfix: Invalid library paths were used in test and example CMake files (#930)
+- Bugfix: The scancode for synthetic key release events was always zero
 - [Win32] Added system error strings to relevant GLFW error descriptions (#733)
 - [Win32] Bugfix: Undecorated windows could not be iconified by the user (#861)
 - [Win32] Bugfix: Deadzone logic could underflow with some controllers (#910)

src/win32_window.c

@@ -1428,10 +1428,16 @@ void _glfwPlatformPollEvents(void)
             // See if this differs from our belief of what has happened
             // (we only have to check for lost key up events)
             if (!lshiftDown && window->keys[GLFW_KEY_LEFT_SHIFT] == 1)
-                _glfwInputKey(window, GLFW_KEY_LEFT_SHIFT, 0, GLFW_RELEASE, mods);
+            {
+                const int scancode = _glfw.win32.scancodes[GLFW_KEY_LEFT_SHIFT];
+                _glfwInputKey(window, GLFW_KEY_LEFT_SHIFT, scancode, GLFW_RELEASE, mods);
+            }
 
             if (!rshiftDown && window->keys[GLFW_KEY_RIGHT_SHIFT] == 1)
-                _glfwInputKey(window, GLFW_KEY_RIGHT_SHIFT, 0, GLFW_RELEASE, mods);
+            {
+                const int scancode = _glfw.win32.scancodes[GLFW_KEY_RIGHT_SHIFT];
+                _glfwInputKey(window, GLFW_KEY_RIGHT_SHIFT, scancode, GLFW_RELEASE, mods);
+            }
         }
     }
 

src/window.c

@@ -50,7 +50,10 @@ void _glfwInputWindowFocus(_GLFWwindow* window, GLFWbool focused)
         for (key = 0;  key <= GLFW_KEY_LAST;  key++)
         {
             if (window->keys[key] == GLFW_PRESS)
-                _glfwInputKey(window, key, 0, GLFW_RELEASE, 0);
+            {
+                const int scancode = _glfwPlatformGetKeyScancode(key);
+                _glfwInputKey(window, key, scancode, GLFW_RELEASE, 0);
+            }
         }
 
         for (button = 0;  button <= GLFW_MOUSE_BUTTON_LAST;  button++)