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

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

* guix/profiles.scm (manifest-transaction-effects): Delete duplicates in
install and remove.  Let multiple upgrades and downgrades shadow previous
transactions of the same kind.
---
 guix/profiles.scm | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/guix/profiles.scm b/guix/profiles.scm
index 1b15257210..99b7dbf299 100644
--- a/guix/profiles.scm
+++ b/guix/profiles.scm
@@ -724,8 +724,11 @@ 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=?)
+                 (reverse upgrade) (reverse downgrade))))
       ((entry rest ...)
        ;; Check whether installing ENTRY corresponds to the installation of a
        ;; new package or to an upgrade.
@@ -740,10 +743,10 @@ replace it."
          (loop rest
                (if previous install (cons entry install))
                (if (and previous newer?)
-                   (alist-cons previous entry upgrade)
+                   (assoc-set! upgrade previous entry)
                    upgrade)
                (if (and previous (not newer?))
-                   (alist-cons previous entry downgrade)
+                   (assoc-set! downgrade previous entry)
                    downgrade)))))))
 
 (define (manifest-perform-transaction manifest transaction)
-- 
2.29.2