Function fl::smush::hrule1_smush

pub fn hrule1_smush(ch1: u8, ch2: u8, hardBlank: u8) -> Option<u8>

Rule 1: EQUAL CHARACTER SMUSHING (code value 1)

Two sub-characters are smushed into a single sub-character if they are the same. This rule does not smush hardblanks. (See rule 6 on hardblanks below)