bug#19151: 24.4; Batch mode doesn't call package-initialize, can't find packages

[npostavs]

Eli Zaretskii <eliz@gnu.org> writes:

>> +It calls the function @code{package-initialize} to activate any
>> +optional Emacs Lisp package that has been installed.  @xref{Packaging
>> +Basics}.  This is not done if @code{package-enable-at-startup} is
>> +@code{nil}, nor if the options @samp{-q}, @samp{-Q}, or @samp{--batch}
>> +were specified.
>
> I would rephrase the last sentence:
>
>   However, when @code{package-enable-at-startup} is @code{nil}, Emacs
>   doesn't initialize packages.  When Emacs is started with one of the
>   options @samp{-q}, @samp{-Q}, or @samp{--batch},
>   @code{package-enable-at-startup} is @code{nil} by default; to
>   initialize packages in that case, explicitly set that variable to a
>   non-@code{nil} value (e.g., via the @samp{--eval} option).

Phrasing is alright, but it's factually inaccurate.  In startup.el we
have

  ;; If any package directory exists, initialize the package system.
  (and user-init-file
       package-enable-at-startup
       ...[lots more file searching]
       (package-initialize))

The -q option sets user-init-file to nil.  I guess we needn't mention
user-init-file by name in the docs as it's an internal detail.  Here's a
new patch:

>From b1d2cf2c2ca86151c25d1c59c7eb210179086be2 Mon Sep 17 00:00:00 2001
From: Noam Postavsky <npostavs@gmail.com>
Date: Fri, 1 Jul 2016 21:15:28 -0400
Subject: [PATCH v2] Explain when package-initialize isn't called

* doc/lispref/os.texi (Startup Summary): Explain that package-initialize
is not called when options -q, -Q, or --batch were passed (Bug #19151).
---
 doc/lispref/os.texi | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/doc/lispref/os.texi b/doc/lispref/os.texi
index 5f189b9..ec14b01 100644
--- a/doc/lispref/os.texi
+++ b/doc/lispref/os.texi
@@ -155,9 +155,13 @@ Startup Summary
 option @samp{--batch} was specified.
 
 @item
-If @code{package-enable-at-startup} is non-@code{nil}, it calls the
-function @code{package-initialize} to activate any optional Emacs Lisp
-package that has been installed.  @xref{Packaging Basics}.
+It calls the function @code{package-initialize} to activate any
+optional Emacs Lisp package that has been installed.  @xref{Packaging
+Basics}.  However, Emacs doesn't initialize packages when
+@code{package-enable-at-startup} is @code{nil} or when it's started
+with one of the options @samp{-q}, @samp{-Q}, or @samp{--batch}.  To
+initialize packages in the latter case, @code{package-initialize}
+should be called explicitly (e.g., via the @samp{--funcall} option).
 
 @vindex after-init-time
 @item
-- 
2.8.0