bug#63260: 29.0.90; Regression installing/activating packages without autoloads

[Basil Contovounesios via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

This change:

  Prevent generating empty autoload files
  dd21003878d 2023-04-30 18:42:58 +0200
  https://git.sv.gnu.org/cgit/emacs.git/commit/?id=dd21003878d

seems to have reintroduced the following issue:

  https://lists.gnu.org/r/emacs-devel/2022-06/msg00563.html

First start Emacs 29 (or 30) with a clean slate:

$ cd "$(mktemp --directory)"
$ export HOME="${PWD}" XDG_CONFIG_HOME="${PWD}/.config"
$ emacs

Then try to install the sicp package (which lacks autoloads) from MELPA:

0. C-x b RET
1. (setq package-archives '(("melpa" . "https://melpa.org/packages/")))
   C-x C-e
2. M-x package-install RET sicp RET
3. C-h e
4. C-M-S-v

Observe that *Messages* contains the line:

  Error loading autoloads:
  (file-missing
   Cannot open load file
   No such file or directory
   /tmp/tmp.5GvMpPatMo/.emacs.d/elpa/sicp-20200512.1137/sicp-autoloads)

5. M-x toggle-debug-on-error RET
6. M-x package-quickstart-refresh RET

This fails with:

  Debugger entered--Lisp error: (wrong-type-argument stringp nil)
    insert-file-contents(nil)
    package-quickstart-refresh()
    funcall-interactively(package-quickstart-refresh)
    call-interactively(package-quickstart-refresh record nil)
    command-execute(package-quickstart-refresh record)
    execute-extended-command(nil "package-quickstart-refresh" "package-quick")
    funcall-interactively(execute-extended-command nil
                          "package-quickstart-refresh"
                          "package-quick")
    call-interactively(execute-extended-command nil nil)
    command-execute(execute-extended-command)
  
The file-missing error also appears on subsequent Emacs startup.

Thanks,

-- 
Basil

In GNU Emacs 29.0.90 (build 1, x86_64-pc-linux-gnu, X toolkit, cairo
 version 1.16.0, Xaw3d scroll bars) of 2023-05-04 built on blc
Repository revision: dd21003878dadba1e0420269e63e10685d4670a9
Repository branch: HEAD
Windowing system distributor 'The X.Org Foundation', version 11.0.12101004
System Description: Ubuntu 22.04.2 LTS

Configured using:
 'configure CC=gcc-12 'CFLAGS=-Og -ggdb3' --prefix=/home/bic/.local
 --with-program-suffix=-29 --with-file-notification=yes --with-x
 --with-x-toolkit=lucid'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2 M17N_FLT MODULES NOTIFY
INOTIFY PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS TREE_SITTER WEBP X11 XAW3D XDBE XIM XINPUT2 XPM
LUCID ZLIB

Important settings:
  value of $LC_MONETARY: en_IE.UTF-8
  value of $LC_NUMERIC: en_IE.UTF-8
  value of $LC_TIME: en_IE.UTF-8
  value of $LANG: en_GB.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Debugger

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  buffer-read-only: t
  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug help-fns cl-print debug backtrace
help-mode find-func compile comint ansi-osc ansi-color ring info
loaddefs-gen lisp-mnt radix-tree tar-mode arc-mode archive-mode cus-edit
pp cus-start cus-load icons wid-edit mm-archive message sendmail
yank-media dired dired-loaddefs rfc822 mml mml-sec epa derived gnus-util
text-property-search time-date mailabbrev gmm-utils mailheader mm-decode
mm-bodies mm-encode mail-utils gnutls network-stream url-cache url-http
url-auth mail-parse rfc2231 rfc2047 rfc2045 mm-util ietf-drums
mail-prsvr url-gw nsm puny epg rfc6068 epg-config finder-inf package
browse-url url url-proxy url-privacy url-expand url-methods url-history
url-cookie generate-lisp-file url-domsuf url-util mailcap url-handlers
url-parse auth-source cl-seq eieio eieio-core cl-macs password-cache
json subr-x map byte-opt gv bytecomp byte-compile url-vars cl-loaddefs
cl-lib rmc iso-transl tooltip cconv eldoc paren electric uniquify
ediff-hook vc-hooks lisp-float-type elisp-mode mwheel term/x-win x-win
term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode lisp-mode prog-mode register
page tab-bar menu-bar rfn-eshadow isearch easymenu timer select
scroll-bar mouse jit-lock font-lock syntax font-core term/tty-colors
frame minibuffer nadvice seq simple cl-generic indonesian philippine
cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech
european ethiopic indian cyrillic chinese composite emoji-zwj charscript
charprop case-table epa-hook jka-cmpr-hook help abbrev obarray oclosure
cl-preloaded button loaddefs theme-loaddefs faces cus-face macroexp
files window text-properties overlay sha1 md5 base64 format env
code-pages mule custom widget keymap hashtable-print-readable backquote
threads dbusbind inotify lcms2 dynamic-setting system-font-setting
font-render-setting cairo x-toolkit xinput2 x multi-tty
make-network-process emacs)

Memory information:
((conses 16 282927 159473)
 (symbols 48 16620 1)
 (strings 32 98218 50117)
 (string-bytes 1 2278870)
 (vectors 16 25526)
 (vector-slots 8 346646 26540)
 (floats 8 46 357)
 (intervals 56 468 3)
 (buffers 984 15))