bug#27564: FFAP on file:// URLs

[積丹尼 Dan Jacobson]

$ cat x
http://example.com/
file:///usr/share/doc/sqlite3-doc/cli.html
file:///usr/share/doc/sqlite3-doc/cli.html#csv_import
$ emacs x
M-x ffap-bindings
Now do C-x C-f on each line.

The first line works fine, prompting with http://example.com/ .
The second and third line fail, with the file:// removed, despite:
ffap-url-regexp is a variable defined in ‘ffap.el’.
Its value is
"\\(news\\(post\\)?:\\|mailto:\\|file:\\|\\(ftp\\|https?\\|telnet\\|gopher\\|www\\|wais\\)://\\)"

(info "(emacs) FFAP") says
If what is found in the buffer has the form of a URL rather than
a file name, the commands use ‘browse-url’ to view it (*note
Browse-URL::).

So file:// end up never passed to browse-url like they should be.

ffap-version"25.2.1"
emacs-version"25.2.1"