#210 planet around barycenter crashes

[Selden Ball]

If one defines a Star with a Planet, one can goto the Planet.

If one replaces the "Star" keyword with "Barycenter"
Celestia r4544 crashes when one tries to GoTo the planet.

It'd be reasonable not to draw the planet, but Celestia should not crash.

Here's the STC I used:

Barycenter "T47"
{
RA 6.021 # degrees = 0.4014 # [hours]
Dec -72.0808 # [degrees]
Distance 1.4681e+04 # [ly]

SpectralType "G2V"
AbsMag 30
Radius 1
}

And here's the SSC I used, a copy of Mars:

"t47_b" "t47"
{
Texture "mars.*"
# Texture "mars8k.dds"
BumpMap "marsbump.*"
BumpHeight 2.5

Color [ 1 0.75 0.7 ]
HazeColor [ 1 1 1 ]
HazeDensity 0.45
Radius 3396 # equatorial
# Oblateness 0.0069

Atmosphere {
Height 30
Lower [ 0.8 0.6 0.6 ]
Upper [ 0.7 0.3 0.3 ]
Sky [ 0.83 0.75 0.65 ]
Sunset [ 0.7 0.7 0.8 ]
# Slightly bluish sunset, as seen in true color pictures
# from Pathfinder

Mie 0.0024
MieAsymmetry -0.15
Rayleigh [ 0.0010 0.0006 0.0003 ]
Absorption [ 0 0 0 ]
MieScaleHeight 20
}

CustomOrbit "vsop87-mars"

# Overridden by CustomOrbit
# EllipticalOrbit
# {
# Period 1.8809
# SemiMajorAxis 1.5237
# Eccentricity 0.0934
# Inclination 1.8506
# AscendingNode 49.479
# LongOfPericenter 336.041
# MeanLongitude 355.453
# }

BodyFrame { EquatorJ2000 {} }
CustomRotation "iau-mars"

# Overriden by CustomRotation
# UniformRotation
# {
# Period 24.622962
# Inclination 26.72
# AscendingNode 82.91
# MeridianAngle 136.005
# }

Albedo 0.150
}

[Chris Laurel]

Verified bug and committed fix (revision 4559.) The crash was caused by the code to display object info. It incorrectly assumed that the list of stars orbiting a barycenter would never be empty. Adding a test for this situation fixed the problem.

[Selden Ball]

Confirmed: One can now go to a planet orbiting an Barycenter and Celestia does not crash.

Thanks!