When pressing backspace on Arabic ligatures (including characters with diacritics), they are removed as if they are one character.
Example: السَّلامُ Pressing 3 backspaces leaves the word at ال. It removed لا which is a ligature combining "ل" and "ا", and removed "م" with diacritics. Compare this with the behavior of zsh. For non-Arabic speakers, this is like typing: fi (U+0046 U+0049), but when pressing backspace it removed it as the character: fi (U+FB01).
