gexp: Native inputs of nested gexps are properly accounted for.

Previously, 'gexp-native-inputs' would not return the native inputs of
nested gexps.  For example, this:

  (gexp-native-inputs #~(foo #$#~(bar #+coreutils)))

would return '().

* guix/gexp.scm (gexp-inputs)[add-reference-inputs]: In the
non-recursive cases, check whether N? and NATIVE? are the same, and act
accordingly.
[native-input?]: Remove.
Fold over all of (gexp-references exp).
* tests/gexp.scm ("ungexp + ungexp-native, nested, special mixture"):
New test.
* tests/gexp.scm ("input list splicing + ungexp-native-splicing"): Pass
 #:native? #t to 'gexp-input'.

1 files changed, 12 insertions, 16 deletions

diff --git a/guix/gexp.scm b/guix/gexp.scm
index fd5dc49233..5021688ac7 100644
--- a/guix/gexp.scm
+++ b/guix/gexp.scm
@@ -678,32 +678,28 @@ references; otherwise, return only non-native references."
        (if (direct-store-path? str)
            (cons `(,str) result)
            result))
-      (($ <gexp-input> (? struct? thing) output)
-       (if (lookup-compiler thing)
+      (($ <gexp-input> (? struct? thing) output n?)
+       (if (and (eqv? n? native?) (lookup-compiler thing))
            ;; THING is a derivation, or a package, or an origin, etc.
            (cons `(,thing ,output) result)
            result))
       (($ <gexp-input> (lst ...) output n?)
-       (fold-right add-reference-inputs result
-                   ;; XXX: For now, automatically convert LST to a list of
-                   ;; gexp-inputs.
-                   (map (match-lambda
-                         ((? gexp-input? x) x)
-                         (x (%gexp-input x "out" (or n? native?))))
-                        lst)))
+       (if (eqv? native? n?)
+           (fold-right add-reference-inputs result
+                       ;; XXX: For now, automatically convert LST to a list of
+                       ;; gexp-inputs.
+                       (map (match-lambda
+                              ((? gexp-input? x) x)
+                              (x (%gexp-input x "out" (or n? native?))))
+                            lst))
+           result))
       (_
        ;; Ignore references to other kinds of objects.
        result)))
 
-  (define (native-input? x)
-    (and (gexp-input? x)
-         (gexp-input-native? x)))
-
   (fold-right add-reference-inputs
               '()
-              (if native?
-                  (filter native-input? (gexp-references exp))
-                  (remove native-input? (gexp-references exp)))))
+              (gexp-references exp)))
 
 (define gexp-native-inputs
   (cut gexp-inputs <> #:native? #t))