bug#23874: [PATCH v2 1/2] profiles: Remove duplicates in manifest transactions.

[Leo Prikler <leo.prikler@student.tugraz.at>]

* guix/profiles.scm (manifest-transaction-effects): Delete duplicate effects.
---
 guix/profiles.scm | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/guix/profiles.scm b/guix/profiles.scm
index 1b15257210..034591eb79 100644
--- a/guix/profiles.scm
+++ b/guix/profiles.scm
@@ -716,6 +716,12 @@ replace it."
     (manifest-pattern
       (name   (manifest-entry-name entry))
       (output (manifest-entry-output entry))))
+  (define manifest-entry-pair=?
+    (match-lambda*
+      (((m1a . m2a) (m1b . m2b))
+       (and (manifest-entry=? m1a m1b)
+            (manifest-entry=? m2a m2b)))
+      (_ #f)))

   (let loop ((input     (manifest-transaction-install transaction))
              (install   '())
@@ -724,8 +730,16 @@ replace it."
     (match input
       (()
        (let ((remove (manifest-transaction-remove transaction)))
-         (values (manifest-matching-entries manifest remove)
-                 (reverse install) (reverse upgrade) (reverse downgrade))))
+         (values (delete-duplicates
+                  (manifest-matching-entries manifest remove)
+                  manifest-entry=?)
+                 (delete-duplicates (reverse install) manifest-entry=?)
+                 (delete-duplicates
+                  (reverse upgrade)
+                  manifest-entry-pair=?)
+                 (delete-duplicates
+                  (reverse downgrade)
+                  manifest-entry-pair=?))))
       ((entry rest ...)
        ;; Check whether installing ENTRY corresponds to the installation of a
        ;; new package or to an upgrade.
--
2.29.2