bug#17788: 24.3; ruler-mode: column indicators "hop" left if you drag them diagonally

[Andrea Rossetti <andrea.rossetti@gmail.com>]

Stephen Berman <stephen.berman@gmx.net> writes:
> I do indeed that the scroll bar on the left (it's also a non-toolkit
> scroll bar, FWIW).
> With your patch, I still get a jump of # when I drag the mouse pointer
> down out of the ruler, but now only by two columns to the left,
> regardless of whether I set the left margin or not.

  Hi Stephen, I confirm that left scroll bar was a relevant
difference between us: if I type "M-S-; (set-scroll-bar-mode 'left) RET"
in ruler-mode I get scroll-bar on left side and see the indicators
"hop" exactly two columns left, same as in your setup.

>> +     (if (eq (posn-area start) 'header-line)
>                            ^^^^^
> I guess this should be `start-or-end-event' (otherwise the byte compiler
> warns about a free variable).

  Ehm... my apologies for that :) I'm now going to post
another version of the patch (can you please throw away the
previous one). Kindest regards,

  Andrea