Hi,

it seems that this bug is quite common amongst shells.
When shell is killed it can mangle its history file,
usually truncate it.
For example do not bother to exit all your shells
and reboot -- oppah, your history gone.
When size of history file comes closer to 1 meg boundary this truncation is
quite repeatable. 

I observed such behaviour with zsh.  Month ago or so it was discussed
at zsh-users.  Maybe it will be fixed in zsh-current.
Now I switched to ksh, and I encountered that same truncation.

Are there shells not suffering that problem?
Could PDKSH in base system switched to something not
suffering that problem?