bug#6687: [24.0.50] end-of-buffer cursor position with an overlay

[Tetsuo Tsukamoto <czkmt@ims.u-tokyo.ac.jp>]

Sorry for many postings,

With additional testings I found the following relationships
between point positions and the cursor behaviors under Emacs
24.0.50.

Invoked Emacs with emacs -Q.  After I moved the point so as to meet
one of the four conditions mentioned in results, I did the
following.

0) M-: (overlay-put (make-overlay (point) (point)) 'before-string "?")
1) Type x.
2) Type additional x.

Results were as follows (cursor position is indicated with [ and ]).

 initial point position  :        cursor behavior
(and (eobp) (eolp))      :  0) [?]   1) [?]x   2) ?xx[]
(and (not (eobp)) (eolp)):  0) [?]   1) ?x[]   2) ?xx[]
(and (eobp) (not (eolp))):  0) ?[]   1) ?x[]   2) ?xx[]
(not (or (eobp) (eolp))) :  0) ?[]   1) ?x[]   2) ?xx[]

Suppose 1st result may not be expected.  2nd result is also
different from what Emacs 23.2 produces. 3rd and 4th results seem
OK.


-- 
Tetsuo Tsukamoto