Standardize how unicode is processed (fixes #8768) (#8770)

Co-authored-by: Konstantin Đorđević <vomindoraan@gmail.com>

1 files changed, 21 insertions, 4 deletions

diff --git a/quantum/process_keycode/process_unicode_common.c b/quantum/process_keycode/process_unicode_common.c
index fb50215012..bea34c31ea 100644
--- a/quantum/process_keycode/process_unicode_common.c
+++ b/quantum/process_keycode/process_unicode_common.c
@@ -171,6 +171,25 @@ void register_hex32(uint32_t hex) {
     }
 }
 
+void register_unicode(uint32_t code_point) {
+    if (code_point > 0x10FFFF || (code_point > 0xFFFF && unicode_config.input_mode == UC_WIN)) {
+        // Code point out of range, do nothing
+        return;
+    }
+
+    unicode_input_start();
+    if (code_point > 0xFFFF && unicode_config.input_mode == UC_MAC) {
+        // Convert code point to UTF-16 surrogate pair on macOS
+        code_point -= 0x10000;
+        uint32_t lo = code_point & 0x3FF, hi = (code_point & 0xFFC00) >> 10;
+        register_hex32(hi + 0xD800);
+        register_hex32(lo + 0xDC00);
+    } else {
+        register_hex32(code_point);
+    }
+    unicode_input_finish();
+}
+
 // clang-format off
 
 void send_unicode_hex_string(const char *str) {
@@ -236,14 +255,12 @@ void send_unicode_string(const char *str) {
         return;
     }
 
-    int32_t code_point = 0;
     while (*str) {
+        int32_t code_point = 0;
         str = decode_utf8(str, &code_point);
 
         if (code_point >= 0) {
-            unicode_input_start();
-            register_hex32(code_point);
-            unicode_input_finish();
+            register_unicode(code_point);
         }
     }
 }