utils: Fix wrap-script argument handling.

* guix/build/utils.scm (wrap-script):
Don't add (car cl) one too many times, cl its self contains it's car.
Split the aguments string with string-tokenize to avoid leaving an empty
string argument when there should be none. These two bugs seemed to
be partially cancelling each other out so that scripts still worked when
ran with no arguments.

* tests/build-utils.scm: Adjust wrap-script to above changes.
Add two tests to ensure the command line arguments appear identical to a
script and its wrapped version.

Signed-off-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>

guix/build/utils.scm

@@ -8,6 +8,7 @@
 ;;; Copyright © 2020 Efraim Flashner <efraim@flashner.co.il>
 ;;; Copyright © 2020, 2021 Maxim Cournoyer <maxim.cournoyer@gmail.com>
 ;;; Copyright © 2021 Maxime Devos <maximedevos@telenet.be>
+;;; Copyright © 2021 Brendan Tildesley <mail@brendan.scot>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -1462,10 +1463,9 @@ not supported."
                                    `(let ((cl (command-line)))
                                       (apply execl ,interpreter
                                              (car cl)
-                                             (cons (car cl)
                                              (append
-                                                    ',(string-split args #\space)
+                                              ',(string-tokenize args char-set:graphic)
-                                                    cl))))))
+                                              cl)))))
                    (template (string-append prog ".XXXXXX"))
                    (out      (mkstemp! template))
                    (st       (stat prog))

tests/build-utils.scm

@@ -3,6 +3,7 @@
 ;;; Copyright © 2019 Ricardo Wurmus <rekado@elephly.net>
 ;;; Copyright © 2021 Maxim Cournoyer <maxim.cournoyer@gmail.com>
 ;;; Copyright © 2021 Maxime Devos <maximedevos@telenet.be>
+;;; Copyright © 2021 Brendan Tildesley <mail@brendan.scot>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -167,9 +168,7 @@ echo hello world"))
                                    "/some/path:/some/other/path"))))
              '(let ((cl (command-line)))
                 (apply execl "/anything/cabbage-bash-1.2.3/bin/sh"
-                       (car cl)
+                       (car cl) (append (quote ()) cl))))
-                       (cons (car cl)
-                             (append '("") cl)))))
      script-contents)
     (call-with-temporary-directory
      (lambda (directory)
@@ -208,8 +207,7 @@ print('hello world')"))
              `(let ((cl (command-line)))
                 (apply execl "/anything/cabbage-bash-1.2.3/bin/python3"
                        (car cl)
-                       (cons (car cl)
+                       (append '("-and" "-args") cl))))
-                             (append '("" "-and" "-args") cl)))))
      script-contents)
     (call-with-temporary-directory
      (lambda (directory)
@@ -243,6 +241,54 @@ print('hello world')"))
                                            "/some/other/path")))
          #f)))))
 
+(define (arg-test bash-args)
+  (call-with-temporary-directory
+   (lambda (directory)
+     (let ((script-file-name (string-append directory "/bash-test.sh")))
+       (call-with-output-file script-file-name
+         (lambda (port)
+           (display (string-append "\
+#!" (which "bash") bash-args "
+echo \"$#$0$*${A}\"")
+                    port)))
+
+       (display "Unwrapped script contents:\n")
+       (call-with-input-file script-file-name
+         (lambda (port) (display (get-string-all port))))
+       (newline) (newline)
+       (chmod script-file-name #o777)
+       (setenv "A" "A")
+       (let* ((run-script (lambda _
+                            (open-pipe*
+                             OPEN_READ
+                             script-file-name "1" "2" "3 3" "4")))
+              (pipe (run-script))
+              (unwrapped-output (get-string-all pipe)))
+         (close-pipe pipe)
+
+         (wrap-script script-file-name `("A" = ("A\nA")))
+
+         (display "Wrapped script contents:\n")
+         (call-with-input-file script-file-name
+           (lambda (port) (display (get-string-all port))))
+         (newline) (newline)
+
+         (let* ((pipe (run-script))
+                (wrapped-output (get-string-all pipe)))
+           (close-pipe pipe)
+           (display "./bash-test.sh 1 2 3\\ 3 4 # Output:\n")
+           (display unwrapped-output) (newline)
+           (display "./bash-test.sh 1 2 3\\ 3 4 # Output (wrapped):\n")
+           (display wrapped-output) (newline)
+           (string=? (string-append unwrapped-output "A\n")
+                     wrapped-output)))))))
+
+(test-assert "wrap-script, argument handling"
+  (arg-test ""))
+
+(test-assert "wrap-script, argument handling, bash --norc"
+  (arg-test " --norc"))
+
 (test-equal "substitute*, text contains a NUL byte, UTF-8"
   "c\0d"
   (with-fluids ((%default-port-encoding "UTF-8")
@@ -287,5 +333,4 @@ print('hello world')"))
           ("guile/bin" . ,(dirname (which "guile"))))
         "guile"))))
 
-
 (test-end)