Access Violation in Cmd.exe When Processing Batch File Script

SYMPTOMS

An access violation may occur in Cmd.exe when processing a batch file script that contains a set statement that sets an environment variable surrounded by % (percent) characters.

For example:

   set %LOG%=c:\tmp\log.txt
				

when LOG is not an existing environment variable.

An access violation may also occur when processing a batch file in which a variable name is set that begins with an equal sign.