Hi,
I use "degenerate" inlinetasks (without an "*** END" line) quite a lot (for
example for "coding" snippets in my orgqda package
https://git.sr.ht/~andersjohansson/orgqda/).

Degenerate inlinetasks are stated as allowed in the documentation at the
beginning of org-inlinetask.el, but are maybe not so common since
org-inlinetask-insert-task always inserts the END-line.

Since April, an infinite loop is caused when cycling an entry containing
degenerate inlinetasks by commit:
5f184b org-inlinetask.el: Fix visibility cycling for inlinetasks

Sample for reproducing:
-----
* Heading
*************** Degenerate inlinetask
-----

Cycling "Heading" will call org-inlinetask-hide-tasks where the last calls
in the loop of `inlinetask-goto-end` takes us to the line below the
inlinetask, but `backward-char` takes us back to the point at the end of
the inlinetask, so `inlinetask-at-task-p` is still t and the loop continues
infinitely in this fashion.

I don’t have a good suggestion for a solution that would still solve the
problem addressed in that commit.

Best,
Anders Johansson