[PyMOL] a minor bug in MacPymol 0.98 beta 27

[Jianghai Zhu]

Hi,

I found out that once in a while macpymol lost memories of previous 
commands. so the "up" key could not bring the previous commands back in 
the external window. I don't know if this only happened to me. It could 
be a minor bug.

Jianghai