Apparently, ReadConsoleInputA() does mistaken sign extension to 16 bits,

rather than writing only the bottom 8 bits of the decoded key to the
event structure. PDCurses, in turn, was reading the whole 16 bits even
in narrow mode, resulting in corrupted "high-bit" characters in wincon.
Potentially an issue since 3.0 (assuming ReadConsoleInputA() always did
this?), but seemingly unreported (?) until now. Reported by Simon
Sobisch.

wincon/pdckbd.c

@@ -331,7 +331,12 @@ static int _get_key_count(void)
 
 static int _process_key_event(void)
 {
-    int key = (unsigned short)KEV.uChar.UnicodeChar;
+    int key =
+#ifdef PDC_WIDE
+        KEV.uChar.UnicodeChar;
+#else
+        KEV.uChar.AsciiChar;
+#endif
     WORD vk = KEV.wVirtualKeyCode;
     DWORD state = KEV.dwControlKeyState;