bug#16497: 24.3.50; `move-to-column' ignores invisible text at the beginning of the line, which create problems when using string-rectangle

[Stefan Monnier]

> emacs -Q
> M-: (insert "abc") RET
> C-a
> M-: (put-text-property (point) (1+ (point)) 'invisible t) RET
> C-a
> C-a
> C-a

> ... !  See the point moving from b to c and back again.

It's probably due to the post-command processing which tries to move
point outside of invisible regions and to pretend that invisible regions
don't exist at all (and paying attention to stickiness so that it
prefers text positions where `invisible' won't be inherited).

So moving from "before a" to "before b" ends up moving to "before c"
so that C-f from "before a" moves visually by one char (to "before c").


        Stefan