+ if (e.keyIdentifier) {
+
+ keydown_keysym = keydown_keysym ||
+ getKeySymFromKeyIdentifier(guac_keyboard.modifiers.shift, e.keyIdentifier);
+
+ // Prevent default if non-typable character or if modifier combination
+ // likely to be eaten by browser otherwise (NOTE: We must not prevent
+ // default for Ctrl+Alt, as that combination is commonly used for
+ // AltGr. If we receive AltGr, we need to handle keypress, which
+ // means we cannot cancel keydown).
+ if (!isTypable(e.keyIdentifier)
+ || ( guac_keyboard.modifiers.ctrl && !guac_keyboard.modifiers.alt)
+ || (!guac_keyboard.modifiers.ctrl && guac_keyboard.modifiers.alt))
+ e.preventDefault();
+
+ }