find-file-suppress-same-file-warnings

find-file-suppress-same-file-warnings is a variable defined in `files.el'.
Its value is

nil

Documentation:
Non-nil means suppress warning messages for symlinked files.
When nil, Emacs prints a warning when visiting a file that is already
visited, but with a different name. Setting this option to t
suppresses this warning.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 21.1 of Emacs.