When a variable is defined in the command line using '-Dvar', an exception occurs. This is because the code accesses the context dictionary using the 'name' variable instead of the 'value' variable.
From Emacs 22, interactive-p is deprecated, and now raises a warning. Reported by Leo Liu.
…dead buffer. Reported by Leo Liu.
…Python3. Reported by Patrik Hartlén and (?) ufleisch.