Function text_concat 

pub unsafe fn text_concat(
    node: *mut _xmlNode,
    str: *const xmlChar,
    num: c_int,
) -> c_int

Concatenate text to a node’s content (upstream tree.c xmlTextConcat): appends num bytes of str to the node’s text content. Returns 0 on success, -1 on error.

SAFETY

• node must be a valid text node or NULL.
• str must be a valid buffer of num bytes.