From 7fbda871c20af19e0cf3597c8dc8dc64885afda0 Mon Sep 17 00:00:00 2001
From: patrickmcquay <60482558+patrickmcquay@users.noreply.github.com>
Date: Mon, 31 Jan 2022 22:51:22 -0500
Subject: [PATCH] real fix for swallowing keys, use a buffer and only process
 one key at a time.

---
 kmk/kmk_keyboard.py | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/kmk/kmk_keyboard.py b/kmk/kmk_keyboard.py
index 1adf21d..c48e0ce 100644
--- a/kmk/kmk_keyboard.py
+++ b/kmk/kmk_keyboard.py
@@ -44,6 +44,7 @@ class KMKKeyboard:
     current_key = None
     matrix_update = None
     secondary_matrix_update = None
+    matrix_update_queue = []
     _matrix_modify = None
     state_changed = False
     _old_timeouts_len = None
@@ -142,7 +143,13 @@ class KMKKeyboard:
 
         int_coord = intify_coordinate(row, col)
 
-        self.current_key = self._find_key_in_map(int_coord, row, col)
+        if not is_pressed:
+            self.current_key = self._coordkeys_pressed[int_coord]
+            if self.debug_enabled:
+                print('PressedKeyResolution(key={})'.format(self.current_key))
+
+        if self.current_key is None:
+            self.current_key = self._find_key_in_map(int_coord, row, col)
 
         if is_pressed:
             self._coordkeys_pressed[int_coord] = self.current_key
@@ -410,10 +417,23 @@ class KMKKeyboard:
 
         self.after_matrix_scan()
 
-        self._handle_matrix_report(self.secondary_matrix_update)
-        self.secondary_matrix_update = None
-        self._handle_matrix_report(self.matrix_update)
-        self.matrix_update = None
+        if self.secondary_matrix_update:
+            # bytearray constructor here to produce a copy
+            # otherwise things get strange when self.secondary_matrix_update
+            # gets modified.
+            self.matrix_update_queue.append(bytearray(self.secondary_matrix_update))
+            self.secondary_matrix_update = None
+
+        if self.matrix_update:
+            # bytearray constructor here to produce a copy
+            # otherwise things get strange when self.matrix_update
+            # gets modified.
+            self.matrix_update_queue.append(bytearray(self.matrix_update))
+            self.matrix_update = None
+
+        # only handle one key per cycle.
+        if self.matrix_update_queue:
+            self._handle_matrix_report(self.matrix_update_queue.pop(0))
 
         self.before_hid_send()