bug#4096: 23.1.50; forward-char sometimes steps over overlay 'display

[Lennart Borgman <lennart.borgman@gmail.com>]

I have two rather similar 'display strings for two invisible
overlays. In one case forward-char steps over the 'display string part
and in the other it stops on it (as it should).

For the case when it steps over the display string looks something like

#("+ <p>...(6 hidden lines)" 0 1
  (face mode-line)
  2 3
  (fontified t)
  3 4
  (face font-lock-function-name-face fontified t)
  4 5
  (fontified t))

and for the case where it stops (expected behaviour) it looks like

#("+...(155 hidden lines)" 0 1
  (face mode-line))

I can reproduce it, but have not made a test case. However the behaviour
can easily be seen in the devel sources for nXhtml. One case is for
outline-minor-mode and one is for hs-minor-mode used in a nxhtml-mode buffer.


In GNU Emacs 23.1.50.1 (i386-mingw-nt5.1.2600)
 of 2009-08-01
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4) --no-opt --cflags
-Ic:/g/include -fno-crossjumping'