bug#14876: 24.3; load-path and environment variable EMACSLOADPATH

[Roland Winkler]

The node "Library Search" suggests to to set EMACSLOADPATH to some
user directory such as /home/foo/.emacs.d/lisp. Yet this does not
agree with the docstring of load-path and emacs fails miserably if
one uses

  export EMACSLOADPATH=/home/foo/.emacs.d/lisp

The proper meaning of EMACSLOADPATH seems to be the one given in the
docstring of load-path saying that EMACSLOADPATH overrides the
default value of load-path specified by file `epaths.h' when Emacs
was built.

The docstring of load-path also says that an element `nil' means
"try default directory". Yet what is the "default directory" in this
context?  default-directory is a buffer-local variable with default nil.

I looked into this because I was looking for a way to _extend_ the
emacs load path in a Makefile generated via autoconf.
Autoconf uses the shell script elisp-comp to compile lisp files.
This script uses

  echo "(setq load-path (cons nil load-path))" > script
  $EMACS -batch -q -l script -f batch-byte-compile *.el || exit $?

In such a hard-coded setting I cannot (easily) extend the load-path via
the emacs option --load.  But the purpose of loading the file script
is not clear to me either.


In GNU Emacs 24.3.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.20.1)
 of 2013-03-27 on regnitz
Windowing system distributor `The X.Org Foundation', version 11.0.10706000
System Description:     Ubuntu 10.04.4 LTS