gtk-text-iter-backward-to-tag-toggle (iter tag)

iter -- a gtk-text-iter instance
tag -- a gtk-text-tag object, or nil

A boolean whether we found a tag toggle before the iterator.

Moves backward to the next toggle (on or off) of the tag, or to the next toggle of any tag if tag is nil.

If no matching tag toggles are found, returns false, otherwise true. Does not return toggles located at the iterator, only toggles before the iterator. Sets the iterator to the location of the toggle, or the start of the text buffer if no toggle is found.