remove mut ref in maybe_get_keybinding

the next_dead_key should be changed only when a key_pressed or a dead key released,don't ask me why, it just make things work right with winit.(all test case passed)

src/window/keyboard_manager.rs

@@ -82,34 +82,34 @@ impl KeyboardManager {
 
                 if !self.should_ignore_input(&settings) {
                     // If we have a keyboard event this frame
-                    let mut prev_dead_key = self.prev_dead_key;
                     for input_event in self.queued_input_events.iter() {
+                        let mut next_dead_key = self.prev_dead_key;
                         match input_event {
                             InputEvent::KeyEvent(key_event) => {
                                 // And a key was pressed
                                 if key_event.state == ElementState::Pressed {
-                                    if let Some(keybinding) =
-                                        self.maybe_get_keybinding(key_event, &mut prev_dead_key)
-                                    {
+                                    if let Some(keybinding) = self.maybe_get_keybinding(key_event) {
                                         EVENT_AGGREGATOR
                                             .send(UiCommand::Serial(SerialCommand::Keyboard(keybinding)));
                                     }
+                                    next_dead_key = None;
                                 } else if key_event.state == ElementState::Released {
                                     // dead key detect here
                                     if let Dead(dead_key) = key_event.logical_key {
-                                        prev_dead_key = dead_key; //should wait for the next input text_with_all_modifiers, and ignore the next ime.
+                                        // should wait for the next input text_with_all_modifiers, and ignore the next ime.
+                                        next_dead_key = dead_key;
                                     }
                                 }
                             }
                             InputEvent::ImeInput(raw_input) => {
-                                if prev_dead_key.is_none() {
+                                if self.prev_dead_key.is_none() {
                                     EVENT_AGGREGATOR
                                         .send(UiCommand::Serial(SerialCommand::Keyboard(raw_input.to_string())));
                                 }
                             }
                         }
+                        self.prev_dead_key = next_dead_key;
                     }
-                    self.prev_dead_key = prev_dead_key;
                 }
 
                 // Regardless of whether this was a valid keyboard input or not, rest ignoring and
@@ -125,29 +125,23 @@ impl KeyboardManager {
         self.ignore_input_this_frame || (self.logo && !settings.use_logo)
     }
 
-    fn maybe_get_keybinding(
-        &self,
-        key_event: &KeyEvent,
-        prev_dead_key: &mut Option<char>,
-    ) -> Option<String> {
+    fn maybe_get_keybinding(&self, key_event: &KeyEvent) -> Option<String> {
         // Determine if this key event represents a key which won't ever
         // present text.
         if let Some(key_text) = is_control_key(key_event.logical_key) {
-            if prev_dead_key.is_some() {
+            if self.prev_dead_key.is_some() {
                 //recover dead key to normal character
-                let real_char = String::from(prev_dead_key.unwrap());
-                *prev_dead_key = None;
+                let real_char = String::from(self.prev_dead_key.unwrap());
                 Some(real_char + &self.format_keybinding_string(true, true, key_text))
             } else {
                 Some(self.format_keybinding_string(true, true, key_text))
             }
         } else {
-            let key_text = if prev_dead_key.is_none() {
+            let key_text = if self.prev_dead_key.is_none() {
                 key_event.text
             } else {
                 key_event.text_with_all_modifiers()
             };
-            *prev_dead_key = None;
             if let Some(ori_key_text) = key_text {
                 let mut key_text = ori_key_text;
                 if self.alt {