Stretched arcs are handled incorrectly in search.c

[Andrew Poelstra]

The function IsPointOnArc() in search.c assumes circular arcs, and does not work correctly with stretched ones.

The easiest way to see this is to try selecting a stretched arc. In the attached PCB, you can select the thick arc from the left side (since the code assumes Width == Radius), but not from the bottom side.

If you want to work on this bug this summer, please let me know, as I am doing some pretty intrusive changes to this area of code and it will be helpful if we do not step on each other's toes.

See also the discussion at
http://archives.seul.org/geda/user/Jul-2011/msg00053.html

[Andrew Poelstra (asp11)]

ArcArcIntersect in find.c also suffers from this bug.

[gpleda.org commit robot (gpleda-launchpad-robot)]

A commit was made which affects this bug
git master commit 8de8bc583834d843933b78db1b2c39540e5008f4
http://git.gpleda.org/?p=pcb.git;a=commit;h=8de8bc583834d843933b78db1b2c39540e5008f4

commit 8de8bc583834d843933b78db1b2c39540e5008f4
Author: Andrew Poelstra <email address hidden>
Commit: Andrew Poelstra <email address hidden>

    Audit search.[ch], implement Coord unit

    This does not affect the "IsPointOnArc assumes circular
    arc" bug; it is just more obvious now with the cleaner
    code.

    Affects-bug: lp-815527