[ic] "if file-e" functionality in user tag?

[Jeff Boes]

I want to create a user tag that produces an "<img>" tag using some
default attributes, and inserting a default image if the cited image is
missing. But the "-e" check in Perl isn't allowed by Safe, so I tried:

if ($Tag->if({ op => 'file-e', term => $file})) {

This reports (at catalog initialization) --

UserTag 'veh_thumb' subroutine failed safe check: Can't call method "if"
on an undefined value at (eval 383) line 11, <CONFIG> line 45.