[comp.sys.ibm.pc] Clipper bugs corrupt FAT

willis@violet.berkeley.edu (Willis Johnson) (04/02/88)

Serious Clipper bugs!

There are currently at least two serious bugs in the Summer '87
version of Clipper which can corrupt the FAT on your hard disk. 
1)  If your application runs on a machine with extended memory,
the load module may over-write the FAT in RAM.  Nantucket claims
that you can avoid this problem by setting a DOS environment
variable "clipper=E000" before running the exe file.  They note
that setting this variable within the file before you compile it
*is not sufficient to solve the problem*.  2)  The FAT may also
get zapped if you run an application compiled with Clipper on a
system that has a disk cache in operation.  Nantucket also
confirms that if you use an unindexed .dbf file greater than 64k,
one record per 64k will become corrupt.  They suggest that you
create a trivial index for such files.  

I had to spend a lot of time collecting this information because
the people at Nantucket have been irresponsibly reticent about
owning up to their mistakes.  I heard of one guy who had to
recall a whole shipment of compiled applications.  I called
Nantucket and told them that I expect better service in the
future and suggest that other Clipper users do the same.

Willis Johnson
  willis@violet.BERKELEY.EDU