bug#12938: 24.2; Lexical binding leaks into package-install somehow

[Magnar Sveen]

Create a test.el file with these contents:

    ;;; -*- lexical-binding: t -*-

    (add-to-list 'package-archives '("melpa" . "http://melpa.milkbox.net/packages/") t)

    (package-initialize)

    (package-refresh-contents)

    (package-install 'multiple-cursors)

And load it. Notice that the compiler warnings includes:

    assignment to free variable `strings'

Remove multiple-cursors from .emacs.d/elpa, change lexical-binding to

nil, and load the file again.

Notice that the compiler warning about 'strings' does not show up.

In other words, the lexical binding in test.el leaks into the

installation of multiple-cursors.

Here is the code in question that generates the warning:

    (defun mc/region-strings ()

      (let ((strings (list (buffer-substring-no-properties (point) (mark)))))

        (mc/for-each-fake-cursor

         (add-to-list 'strings (buffer-substring-no-properties

                                (mc/cursor-beg cursor)

                                (mc/cursor-end cursor))))

        strings))

    (defmacro mc/for-each-fake-cursor (&rest forms)

      "Runs the body for each fake cursor, bound to the name cursor"

      `(mapc #'(lambda (cursor) ,@forms)

             (mc/all-fake-cursors)))

In GNU Emacs 24.2.1 (x86_64-apple-darwin10.8.0, NS apple-appkit-1038.36)

 of 2012-09-04 on fi-bp-202.local

Windowing system distributor `Apple', version 10.3.1038

Configured using:

 `configure '--prefix=/usr/local/Cellar/emacs/24.2' '--without-dbus'

 '--enable-locallisppath=/usr/local/share/emacs/site-lisp'

 '--infodir=/usr/local/Cellar/emacs/24.2/share/info/emacs' '--with-ns'

 '--disable-ns-self-contained' 'CC=/usr/bin/gcc-4.2' 'CFLAGS=-Os -w

 -pipe -march=core2 -msse4 -mmacosx-version-min=10.6'

 'LDFLAGS=-L/usr/local/lib''

Important settings:

  value of $LC_ALL: nil

  value of $LC_COLLATE: nil

  value of $LC_CTYPE: nil

  value of $LC_MESSAGES: nil

  value of $LC_MONETARY: nil

  value of $LC_NUMERIC: nil

  value of $LC_TIME: nil

  value of $LANG: nil

  value of $XMODIFIERS: nil

  locale-coding-system: utf-8

  default enable-multibyte-characters: t

Major mode: Emacs-Lisp

Minor modes in effect:

  diff-auto-refine-mode: t

  elisp-slime-nav-mode: t

  show-paren-mode: t

  global-hl-line-mode: t

  ido-ubiquitous-mode: t

  wrap-region-global-mode: t

  wrap-region-mode: t

  persp-mode: t

  yas/global-mode: t

  yas/minor-mode: t

  global-undo-tree-mode: t

  undo-tree-mode: t

  global-subword-mode: t

  subword-mode: t

  shell-dirtrack-mode: t

  recentf-mode: t

  delete-selection-mode: t

  global-auto-revert-mode: t

  mouse-wheel-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

  column-number-mode: t

  line-number-mode: t

  transient-mark-mode: t

Recent input:

<down> <down> <down> <down> <down> <down> <down> <down>

<down> <down> <down> <left> <C-left> <C-left> <C-left>

<C-left> <C-left> <C-left> <C-right> <right> <right>

<up> <right> <C-right> <C-right> <C-right> <C-right>

<C-right> <C-right> <C-right> <C-right> <C-left> M-w

q <up> <up> <up> <up> <return> C-y <return> C-_ C-_

C-_ <down> <down> <up> <up> <return> C-y C-_ C-_ <down>

<up> <return> C-y <return> <up> <up> M-j <down> C-k

<down> <down> <down> C-x C-s C-x C-f e l p <backspace>

<backspace> <backspace> . e m <return> e l <return>

C-d <down> <down> <down> <down> <down> <down> <down>

<down> <down> <down> <down> <down> <down> <down> <down>

D y y <up> <up> <up> q <up> <up> <up> <up> <up> <left>

<left> <left> <left> <left> <backspace> n i l <down>

<down> <down> <down> <down> <down> C-x C-s M-: <up>

<return> y <S-right> C-s s t r i n g s C-s C-s C-s

<up> <up> <up> <up> <up> <home> C-x k <return> C-x

0 <up> <up> <up> <up> <up> <left> <C-left> C-d C-d

C-d t <down> <down> <down> <down> <down> <down> <down>

<up> <up> <up> <up> <up> <up> <backspace> n i l C-x

C-s <down> <down> <down> <down> <down> C-x f e l p

C-g C-x C-f <return> <return> C-d g <down> <down> <down>

<up> <down> D y y q <down> C-x C-s M-: <down> <up>

<return> y <S-right> <end> <home> <end> <home> C-s

s t r i n g s C-s C-s C-s <down> <down> <up> <up> C-x

k y <backspace> <return> C-x 0 <up> <up> <up> <up>

<up> <C-left> M-d t C-x C-s <down> <down> <down> <down>

C-x C-f <return> <return> C-d f q g <up> D y y q M-:

<up> <return> y <S-right> q <down> <down> C-SPC <C-up>

<C-up> M-w <down> <down> <down> <down> <down> <down>

<down> M-x r e p o r t - <return>

Recent messages:

Compiling /Users/fimasvee/.emacs.d/elpa/multiple-cursors-20121118.2110/multiple-cursors.el...done

Wrote /Users/fimasvee/.emacs.d/elpa/multiple-cursors-20121118.2110/multiple-cursors.elc

Checking /Users/fimasvee/.emacs.d/elpa/multiple-cursors-20121118.2110...

Compiling /Users/fimasvee/.emacs.d/elpa/multiple-cursors-20121118.2110/rectangular-region-mode.el...done

Wrote /Users/fimasvee/.emacs.d/elpa/multiple-cursors-20121118.2110/rectangular-region-mode.elc

Checking /Users/fimasvee/.emacs.d/elpa/multiple-cursors-20121118.2110...

Done (Total of 7 files compiled, 1 skipped)

Loading /Users/fimasvee/test.el (source)...done

t

Mark set

line-move-visual: End of buffer

Load-path shadows:

/Users/fimasvee/.emacs.d/elpa/php-mode-20121015.6/php-mode hides /Users/fimasvee/.emacs.d/site-lisp/php-mode/php-mode

/Users/fimasvee/.emacs.d/elpa/multiple-cursors-20121118.2110/rectangular-region-mode hides /Users/fimasvee/.emacs.d/site-lisp/multiple-cursors/rectangular-region-mode

/Users/fimasvee/.emacs.d/elpa/multiple-cursors-20121118.2110/multiple-cursors hides /Users/fimasvee/.emacs.d/site-lisp/multiple-cursors/multiple-cursors

/Users/fimasvee/.emacs.d/elpa/multiple-cursors-20121118.2110/multiple-cursors-pkg hides /Users/fimasvee/.emacs.d/site-lisp/multiple-cursors/multiple-cursors-pkg

/Users/fimasvee/.emacs.d/elpa/multiple-cursors-20121118.2110/multiple-cursors-core hides /Users/fimasvee/.emacs.d/site-lisp/multiple-cursors/multiple-cursors-core

/Users/fimasvee/.emacs.d/elpa/multiple-cursors-20121118.2110/mc-mark-more hides /Users/fimasvee/.emacs.d/site-lisp/multiple-cursors/mc-mark-more

/Users/fimasvee/.emacs.d/elpa/multiple-cursors-20121118.2110/mc-edit-lines hides /Users/fimasvee/.emacs.d/site-lisp/multiple-cursors/mc-edit-lines

/Users/fimasvee/.emacs.d/elpa/multiple-cursors-20121118.2110/mc-cycle-cursors hides /Users/fimasvee/.emacs.d/site-lisp/multiple-cursors/mc-cycle-cursors

/Users/fimasvee/.emacs.d/site-lisp/s/examples hides /Users/fimasvee/.emacs.d/site-lisp/dash/examples

/Users/fimasvee/.emacs.d/site-lisp/s/examples-to-tests hides /Users/fimasvee/.emacs.d/site-lisp/dash/examples-to-tests

/Users/fimasvee/.emacs.d/site-lisp/s/examples-to-docs hides /Users/fimasvee/.emacs.d/site-lisp/dash/examples-to-docs

/Users/fimasvee/.emacs.d/site-lisp/s/ert hides /Users/fimasvee/.emacs.d/site-lisp/dash/ert

/Users/fimasvee/.emacs.d/site-lisp/fill-column-indicator/fill-column-indicator hides /Users/fimasvee/.emacs.d/site-lisp/fill-column-indicator

~/.emacs.d/users/fimasvee/init hides /Users/fimasvee/.emacs.d/init

/Users/fimasvee/.emacs.d/elpa/magit-20121030.2025/rebase-mode hides /usr/local/share/emacs/site-lisp/rebase-mode

/Users/fimasvee/.emacs.d/site-lisp/delsel/delsel hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/delsel

/Users/fimasvee/.emacs.d/custom hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/custom

/usr/local/share/emacs/site-lisp/trampver hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/net/trampver

/usr/local/share/emacs/site-lisp/tramp hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/net/tramp

/usr/local/share/emacs/site-lisp/tramp-uu hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/net/tramp-uu

/usr/local/share/emacs/site-lisp/tramp-smb hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/net/tramp-smb

/usr/local/share/emacs/site-lisp/tramp-sh hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/net/tramp-sh

/usr/local/share/emacs/site-lisp/tramp-loaddefs hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/net/tramp-loaddefs

/usr/local/share/emacs/site-lisp/tramp-gw hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/net/tramp-gw

/usr/local/share/emacs/site-lisp/tramp-ftp hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/net/tramp-ftp

/usr/local/share/emacs/site-lisp/tramp-compat hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/net/tramp-compat

/usr/local/share/emacs/site-lisp/tramp-cmds hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/net/tramp-cmds

/usr/local/share/emacs/site-lisp/tramp-cache hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/net/tramp-cache

/Users/fimasvee/.emacs.d/elpa/magit-20121030.2025/.dir-locals hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/gnus/.dir-locals

/Users/fimasvee/.emacs.d/site-lisp/s/ert hides /usr/local/Cellar/emacs/24.2/share/emacs/24.2/lisp/emacs-lisp/ert

Features:

(shadow sort mail-extr emacsbug message rfc822 mml mml-sec mm-decode

mm-bodies mailabbrev gmm-utils mailheader sendmail

multiple-cursors-autoloads tar-mode sh-script executable term ehelp

electric pp timezone cus-edit cus-start cus-load octomacs

setup-ruby-mode ruby-mode-expansions ruby-mode markdown-mode mule-util

cal-move octomacs-autoloads autoload mail-utils parse-time

network-stream starttls url-cache url-http tls url-gw url-auth url

url-proxy url-privacy url-expand url-methods url-history url-cookie

yaml-mode find-dired vc ediff-merg ediff-diff ediff-wind ediff-help

ediff-util ediff-mult ediff-init ediff vc-dispatcher rebase-mode rx

conf-mode setup-js2-mode js2-imenu-extras js2-refactor js2r-conveniences

js2r-conditionals js2r-wrapping js2r-functions js2r-vars js2r-iife

js2r-formatting js2r-helpers disp-table js2-mode-expansions js2-mode

cc-langs css-mode-expansions css-mode ibuf-ext ibuffer dired-x

zencoding-mode rename-sgml-tag crappy-jsp-mode js-mode-expansions js

newcomment cc-mode-expansions cc-mode cc-fonts cc-guess cc-menus cc-cmds

cc-styles cc-align cc-engine cc-vars cc-defs jsp-expansions

html-mode-expansions sgml-mode org-wl org-w3m org-vm org-rmail org-mhe

org-mew org-irc org-jsinfo org-infojs org-html org-exp ob-exp

org-exp-blocks org-agenda org-info org-gnus org-docview org-bibtex

bibtex org-bbdb setup-org org-mode-expansions org ob-emacs-lisp

ob-tangle ob-ref ob-lob ob-table org-footnote org-src ob-comint ob-keys

ob ob-eval org-pcomplete org-list org-faces org-compat org-entities

org-macs noutline outline cal-menu calendar cal-loaddefs hippie-exp

misearch multi-isearch tabify setup-magit magit-svn magit-bisect

magit-key-mode magit diff-mode log-edit pcvs-util add-log vc-git unsafep

elisp-slime-nav etags oppdrag-mode diminish server mac my-misc

appearance zoom-frm frame-cmds frame-fns avoid paren hl-line

key-bindings windmove smex setup-ido ido-ubiquitous ido browse-kill-ring

fill-column-indicator multifiles change-inner smart-forward wgrep

setup-rgrep grep compile eproject esh-var esh-io esh-cmd esh-ext

esh-proc esh-arg eldoc esh-groups eshell esh-module esh-mode esh-util

jump-char multiple-cursors rectangular-region-mode mc-mark-more

thingatpt mc-cycle-cursors mc-edit-lines multiple-cursors-core rect

inline-string-rectangle mark-more-like-this mark-multiple expand-region

text-mode-expansions expand-region-custom expand-region-core s

file-defuns imenu mode-mappings setup-paredit paredit setup-html-mode

setup-ffip find-file-in-project setup-wrap-region wrap-region

setup-perspective perspective setup-ace-jump-mode ace-jump-mode

setup-yasnippet buster-snippets buster-snippet-helpers yasnippet

dropdown-list help-mode view setup-hippie setup-shell shell-command

setup-dired dired-details dash exec-path-from-shell sane-defaults

uniquify undo-tree edmacro kmacro diff smooth-scrolling warnings subword

winner tramp-cache tramp-sh tramp tramp-compat tramp-loaddefs shell

pcomplete comint ansi-color ring format-spec advice advice-preload

recentf tree-widget wid-edit delsel easy-mmode autorevert setup-package

clojure-test-mode-autoloads elisp-slime-nav-autoloads elnode-autoloads

elnode ert derived help-fns find-func ewoc easymenu debug cl dired

regexp-opt db json web dotassoc kv url-util url-parse auth-source assoc

gnus-util password-cache url-vars mailcap mm-encode mail-parse rfc2231

rfc2047 rfc2045 ietf-drums mm-util mail-prsvr creole-autoloads

db-autoloads exec-path-from-shell-autoloads fakir-autoloads

gist-autoloads gh-autoloads eieio byte-opt bytecomp byte-compile cconv

macroexp htmlize-autoloads kv-autoloads logito-autoloads magit-autoloads

nrepl-autoloads clojure-mode-autoloads paredit-autoloads

pcache-autoloads finder-inf php-mode-autoloads slime-js-autoloads

slime-repl-autoloads slime-autoloads web-autoloads package

tabulated-list setup-elnode saveplace time-date tooltip ediff-hook

vc-hooks lisp-float-type mwheel ns-win tool-bar dnd fontset image fringe

lisp-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 loaddefs button faces cus-face files text-properties overlay

sha1 md5 base64 format env code-pages mule custom widget

hashtable-print-readable backquote make-network-process ns multi-tty

emacs)