Re: bug: epg send unencrypted data in trash

[Ted Zlatanov <tzz@lifelogs.com>]

On Fri, 11 Feb 2011 19:23:06 -0500 Chong Yidong <cyd@stupidchicken.com> wrote: 

CY> I think TV is using the emacs-23 branch, where the TRASH parameter is
CY> not present.  I've changed EPA and EPG to bind delete-by-moving-to-trash
CY> to nil there.  No fix is necessary for the trunk, IIUC.

A good reason to use M-x report-emacs-bug which collects the version :)

I still don't understand the parameter definition and would appreciate
some guidance.  How does TRASH get set based on called-interactively-p,
as claimed by the docstring?

DEFUN ("delete-file", Fdelete_file, Sdelete_file, 1, 2,
       "(list (read-file-name \
                (if (and delete-by-moving-to-trash (null current-prefix-arg)) \
                    \"Move file to trash: \" \"Delete file: \") \
                nil default-directory (confirm-nonexistent-file-or-buffer)) \
              (null current-prefix-arg))",
       doc: /* Delete file named FILENAME.  If it is a symlink, remove the symlink.
If file has multiple names, it continues to exist with the other names.
TRASH non-nil means to trash the file instead of deleting, provided
`delete-by-moving-to-trash' is non-nil.

When called interactively, TRASH is t if no prefix argument is given.
With a prefix argument, TRASH is nil.  */)

I don't see anything in the body of the function to set TRASH, either.
Is it claimed because we assume `current-prefix-arg' is always null
non-interactively and `universal-arg' is always called interactively?

Thanks
Ted