Ctrl+f in text field should not type 'f'

src/dialogxml/keycodes.hpp

@@ -40,7 +40,7 @@ enum eSpecKey {
 	key_esc, key_enter, key_tab, key_help, // key_help should bind to the help key on Mac and the F1 key on Windows
 	key_bsp, key_del, key_home, key_end, key_pgup, key_pgdn, key_top, key_bottom, key_insert,
 	key_copy, key_cut, key_paste, key_selectall, key_undo, key_redo,
-	key_word_left, key_word_right, key_word_bsp, key_word_del,
+	key_word_left, key_word_right, key_word_bsp, key_word_del, key_none
 };
 
 /// Represents a keypress.

src/dialogxml/widgets/field.cpp

@@ -376,6 +376,10 @@ static cKey divineFunction(cKey key) {
 			} else if(key.c == 'y') {
 				key.spec = true;
 				key.k = key_redo;
+			} else {
+				// Ctrl+random key: do nothing. Don't type the key.
+				key.spec = true;
+				key.k = key_none;
 			}
 		}
 		if(key.spec) key.mod -= mod_ctrl;