Tal Kelrich spotted that hitting `Solve' on a configuration which is

Tal Kelrich spotted that hitting `Solve' on a configuration which is
laser-indistinguishable from the right solution _but_ has a number
of balls outside the acceptable range does not report an error. His
example was the game ID w8h8m5M5:1e3e6e80fa3e16265ccef7ca , omitting
the rightmost ball in the second row.

[originally from svn r6542]