bug#21347: include-from-path and relative paths in load-path

[Taylan Ulrich Bayırlı/Kammer]

When there are relative paths in the load-path, `include-from-path'
seems to always interpret them relative to the directory of the file in
which the `include-from-path' is called, instead of relative to the
current working directory in effect when Guile is started.

Transcript:

--- SNIP ---
address@hidden:~$ unset GUILE_LOAD_COMPILED_PATH
address@hidden:~$ unset GUILE_LOAD_PATH
address@hidden:~$ echo '(display "foo\n")' > display.scm
address@hidden:~$ mkdir test
address@hidden:~$ echo '(include-from-path "display.scm")' > test/test.scm
address@hidden:~$ guile -q -L .
GNU Guile 2.0.11
Copyright (C) 1995-2014 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guile-user)> (load "test/test.scm")
;;; note: auto-compilation is enabled, set GUILE_AUTO_COMPILE=0
;;;       or pass the --no-auto-compile argument to disable.
;;; compiling /home/taylan/test/test.scm
;;; WARNING: compilation of /home/taylan/test/test.scm failed:
;;; ERROR: In procedure open-file: No such file or directory: 
"/home/taylan/test/./display.scm"
ERROR: In procedure open-file:
ERROR: In procedure open-file: No such file or directory: 
"/home/taylan/test/./display.scm"

Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
scheme@(guile-user) [1]>
--- SNIP ---

Is this behavior desired?  I would say not, because when passing "-L ."
to guile, one expects the current directory to be added to the load
path, not some symbolic "current directory" whose true value changes
dynamically.  (Well, I could understand if there were an explicit
`chdir' call, though even then I think the "."  would ideally be
evaluated once at startup, if possible.)

Taylan