More procedure-arguments-alist documentation and a bugfix

* doc/ref/api-procedures.texi (Compiled Procedures): Expand
  program-arguments-alist and program-lambda-list documentation.

* module/system/vm/program.scm (arity->arguments-alist): Fix the rest
  arg if there are also keyword args, a bug found while documenting!

* test-suite/tests/session.test ("procedure-arguments"): Update.

doc/ref/api-procedures.texi

@@ -1,7 +1,7 @@
 @c -*-texinfo-*-
 @c This is part of the GNU Guile Reference Manual.
 @c Copyright (C)  1996, 1997, 2000, 2001, 2002, 2003, 2004, 2009, 2010,
-@c   2011, 2012  Free Software Foundation, Inc.
+@c   2011, 2012, 2013  Free Software Foundation, Inc.
 @c See the file guile.texi for copying conditions.
 
 @node Procedures
@@ -271,7 +271,25 @@ sense at certain points in the program, delimited by these
 @end deffn
 
 @deffn {Scheme Procedure} program-arguments-alist program [ip]
-@deffnx {Scheme Procedure} program-lambda-list [ip]
+Return an association list describing the arguments that @var{program} accepts, or
+@code{#f} if the information cannot be obtained.
+
+For example:
+@example
+(program-arguments-alist
+ (lambda* (a b #:optional c #:key (d 1) #:rest e)
+   #t)) @result{}
+((required . (a b))
+ (optional . (c))
+ (keyword . ((#:d . 4)))
+ (allow-other-keys? . #f)
+ (rest . d))
+@end example
+
+The alist keys that are currently defined are `required', `optional',
+`keyword', `allow-other-keys?', and `rest'.
+
+@deffnx {Scheme Procedure} program-lambda-list program [ip]
 Accessors for a representation of the arguments of a program, with both
 names and types (ie. either required, optional or keywords)
 

module/system/vm/program.scm

@@ -1,6 +1,6 @@
 ;;; Guile VM program functions
 
-;;; Copyright (C) 2001, 2009, 2010 Free Software Foundation, Inc.
+;;; Copyright (C) 2001, 2009, 2010, 2013 Free Software Foundation, Inc.
 ;;;
 ;;; This library is free software; you can redistribute it and/or
 ;;; modify it under the terms of the GNU Lesser General Public
@@ -227,7 +227,7 @@
           rest? rest (1+ n)))
      (rest?
       (lp nreq req nopt opt
-          #f (var-by-index n)
+          #f (var-by-index (+ n (length (arity:kw arity))))
           (1+ n)))
      (else
       `((required . ,(reverse req))

test-suite/tests/session.test

@@ -1,7 +1,7 @@
 ;;;; session.test --- test suite for (ice-9 session)   -*- scheme -*-
 ;;;; Jose Antonio Ortega Ruiz <jao@gnu.org> -- August 2010
 ;;;;
-;;;; 	Copyright (C) 2010, 2012 Free Software Foundation, Inc.
+;;;; 	Copyright (C) 2010, 2012, 2013 Free Software Foundation, Inc.
 ;;;;
 ;;;; This library is free software; you can redistribute it and/or
 ;;;; modify it under the terms of the GNU Lesser General Public
@@ -88,7 +88,7 @@
     (lambda* (a b #:optional o p #:key k l #:rest r) #f)
     ((required . (a b)) (optional . (o p))
      (keyword . ((#:k . 5) (#:l . 6))) (allow-other-keys? . #f)
-     (rest . k)))
+     (rest . r)))
 
   (pass-if "aok? is preserved"
     ;; See <http://bugs.gnu.org/10938>.