`backward-sexp' does not signal when there is no form before point; it goes to
the beginning of the buffer and stays there. At point-min that is no movement,
so the form the dispatch then looked at was the one *after* point -- whose head
is very often a declaration -- and the region between start and end was empty.
The key installed the file's first declaration by name with no body, which the
daemon accepts, and the echo area reported it as a change. Both paths check for
movement now: the predicate refuses, and the expression arm refuses in words
rather than asking the daemon to evaluate the empty string.
The same predicate asked only for the depth at the open delimiter, and a form
written at column 1 inside a comment or a string is at depth 0 like any other.
A `defvar' in a comment is prose; it is not offered as a declaration any more.
Depth in a narrowed buffer still means depth within the narrowing, which is
noted where it is read rather than changed.
Joseph Ferano
eed0cfa950