bug#20391: 24.5; Info-menu completing-read doesn't use DEF argument

[Howard Melman]

The Info-menu command in info.el uses completing-read but doesn't use the
DEF argument. As a result, helm fails to choose the right default
when invoked on an info menu line.

Doing the obvious and appending "nil nil default" to completing-read
in the Info-menu call did solve the problem for me with helm and did
seem to still work without helm, but I'm not completely confident it's
the correct thing. 

The next few lines of Info-menu say it's depending on completing-read
allowing "" even when require-match is t and "" is invalid, but it just
seems to be doing so to loop back to read another input.

Howard

In GNU Emacs 24.5.1 (x86_64-apple-darwin13.4.0, NS apple-appkit-1265.21)
of 2015-04-10 on builder10-9.porkrind.org
Windowing system distributor `Apple', version 10.3.1347
Configured using:
`configure --with-ns '--enable-locallisppath=/Library/Application
Support/Emacs/${version}/site-lisp:/Library/Application
Support/Emacs/site-lisp''

Important settings:
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  eldoc-mode: t
  helm-mode: t
  shell-dirtrack-mode: t
  outline-minor-mode: t
  auto-insert-mode: t
  global-auto-revert-mode: t
  which-function-mode: t
  show-paren-mode: t
  recentf-mode: t
  tooltip-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  size-indication-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent messages:
Loading /Users/hmelman/.simplenote2/.notes-info.el (source)...done
Loading hrm-packages...done
Loading hrm-helm...
ad-handle-definition: `tramp-read-passwd' got redefined
Helm completion enabled
Loading hrm-helm...done
Loading hrm-keys...done
Loading hrm...done
Finished loading ~/.emacs
For information about GNU Emacs and the GNU system, type M-x about-emacs.

Load-path shadows:
/Users/hmelman/.emacs.d/elpa/smartparens-20150419.833/smartparens hides 
/Users/hmelman/elisp/smartparens
/Users/hmelman/.emacs.d/elpa/google-this-20150226.2005/google-this hides 
/Users/hmelman/elisp/google-this

Features:
(shadow sort face-remap mail-extr emacsbug message rfc822 mml mml-sec
mm-decode mm-bodies mm-encode mailabbrev gmm-utils mailheader sendmail
winner helm-command helm-elisp helm-eval eldoc lisp-mnt helm-swoop
helm-mode helm-files rx image-dired tramp tramp-compat tramp-loaddefs
trampver shell dired-aux ffap thingatpt helm-buffers helm-elscreen
helm-tags helm-bookmark helm-adaptive helm-info bookmark pp helm-locate
helm-help helm-org helm-match-plugin helm-grep helm-regexp helm-plugin
grep helm-external helm-net browse-url xml helm-utils compile helm
helm-source helm-config edmacro kmacro async-bytecomp cl-macs async
helm-aliases hydra lv simplenote2 request-deferred deferred cl gv
request url-http tls url-auth mail-parse rfc2231 rfc2047 rfc2045
ietf-drums url-gw mail-utils url url-proxy url-privacy url-expand
url-methods url-history url-cookie url-domsuf mailcap hungry-delete
dired-x dired org-location-google-maps org-agenda google-maps
google-maps-static url-util url-parse auth-source eieio byte-opt
bytecomp byte-compile cl-extra cconv eieio-core gnus-util mm-util
mail-prsvr password-cache url-vars google-maps-geocode google-maps-base
json org org-macro org-footnote org-pcomplete pcomplete org-list
org-faces org-entities noutline outline easy-mmode org-version ob-R
ob-emacs-lisp ob ob-tangle ob-ref ob-lob ob-table ob-exp org-src ob-keys
ob-comint comint ansi-color ring ob-core ob-eval org-compat org-macs
org-loaddefs format-spec cal-menu calendar cal-loaddefs autoinsert
advice help-fns autorevert filenotify find-func info package epg-config
saveplace tango-theme which-func imenu paren recentf tree-widget
wid-edit cl-loaddefs cl-lib easymenu cus-start cus-load time-date
tooltip electric uniquify ediff-hook vc-hooks lisp-float-type mwheel
ns-win tool-bar dnd fontset image regexp-opt fringe tabulated-list
newcomment lisp-mode prog-mode register page menu-bar rfn-eshadow timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
frame cham georgian utf-8-lang misc-lang vietnamese tibetan thai
tai-viet lao korean japanese hebrew greek romanian slovak czech european
ethiopic indian cyrillic chinese case-table epa-hook jka-cmpr-hook help
simple abbrev minibuffer nadvice loaddefs button faces cus-face macroexp
files text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote make-network-process
cocoa ns multi-tty emacs)

Memory information:
((conses 16 288177 9414)
(symbols 48 39157 0)
(miscs 40 84 95)
(strings 32 79279 9567)
(string-bytes 1 2344094)
(vectors 16 30502)
(vector-slots 8 600497 8348)
(floats 8 726 67)
(intervals 56 364 0)
(buffers 960 13))