[bug#43578] [PATCH 3/4] packages: 'package-mapping' correctly recurses into 'replacement'.

["Ludovic Courtès" <ludo@gnu.org>]

Previously, something like:

  guix build glib --with-graft=glibc=glibc@2.29

would produce a result showing that rewriting rules were not applied to
libx11@1.6.A (a replacement).

* guix/packages.scm (package-mapping): Call REPLACE instead of PROC to
'replacement'.
* tests/packages.scm ("package-input-rewriting/spec, graft"): New test.
---
 guix/packages.scm  |  2 +-
 tests/packages.scm | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/guix/packages.scm b/guix/packages.scm
index f696945e30..0d0d7492b6 100644
--- a/guix/packages.scm
+++ b/guix/packages.scm
@@ -1037,7 +1037,7 @@ applied to implicit inputs as well."
               (inputs (map rewrite (package-inputs p)))
               (native-inputs (map rewrite (package-native-inputs p)))
               (propagated-inputs (map rewrite (package-propagated-inputs p)))
-              (replacement (and=> (package-replacement p) proc))
+              (replacement (and=> (package-replacement p) replace))
               (properties `((,mapping-property . #t)
                             ,@(package-properties p))))))))
 
diff --git a/tests/packages.scm b/tests/packages.scm
index 6fa4ad2f1b..e31dea6f72 100644
--- a/tests/packages.scm
+++ b/tests/packages.scm
@@ -1364,6 +1364,33 @@
     (match (delete-duplicates pythons eq?)
       ((p) (eq? p (rewrite python))))))
 
+(test-equal "package-input-rewriting/spec, graft"
+  (derivation-file-name (package-derivation %store sed))
+
+  ;; Make sure replacements are rewritten.
+  (let* ((dep0 (dummy-package "dep"
+                 (version "1")
+                 (build-system trivial-build-system)
+                 (inputs `(("coreutils" ,coreutils)))))
+         (dep1 (dummy-package "dep"
+                 (version "0")
+                 (build-system trivial-build-system)
+                 (replacement dep0)))
+         (p0   (dummy-package "p"
+                 (build-system trivial-build-system)
+                 (inputs `(("dep" ,dep1)))))
+         (rewrite (package-input-rewriting/spec
+                   `(("coreutils" . ,(const sed)))))
+         (p1      (rewrite p0)))
+    (match (package-inputs p1)
+      ((("dep" dep))
+       (match (package-inputs (package-replacement dep))
+         ((("coreutils" coreutils))
+          ;; COREUTILS is not 'eq?' to SED, so the most reliable way to check
+          ;; for equality is to lower to a derivation.
+          (derivation-file-name
+           (package-derivation %store coreutils))))))))
+
 (test-equal "package-patched-vulnerabilities"
   '(("CVE-2015-1234")
     ("CVE-2016-1234" "CVE-2018-4567")
-- 
2.28.0