org-up-heading-safe

org-up-heading-safe is a compiled Lisp function in `org.el'.

(org-up-heading-safe)

Move to the heading line of which the present line is a subheading.
This version will not throw an error. It will return the level of the
headline found, or nil if no higher level is found.

Also, this function will be a lot faster than `outline-up-heading',
because it relies on stars being the outline starters. This can really
make a significant difference in outlines with very many siblings.