git: 'update-cached-checkout' returns the commit relation.

* guix/git.scm (update-cached-checkout): Add #:starting-commit
parameter.  Call 'commit-relation' when #:starting-commit is true.
Always return the relation or #f as the third value.
(latest-repository-commit): Adjust accordingly.
* guix/import/opam.scm (get-opam-repository): Likewise.
* tests/channels.scm ("latest-channel-instances includes channel dependencies")
("latest-channel-instances excludes duplicate channel dependencies"):
Update mock of 'update-cached-checkout' accordingly.

1 files changed, 6 insertions, 6 deletions

diff --git a/tests/channels.scm b/tests/channels.scm
index 910088ba157..3578b57204c 100644
--- a/tests/channels.scm
+++ b/tests/channels.scm
@@ -136,11 +136,11 @@
                    (url "test")))
          (test-dir (channel-instance-checkout instance--simple)))
     (mock ((guix git) update-cached-checkout
-           (lambda* (url #:key ref)
+           (lambda* (url #:key ref starting-commit)
              (match url
-               ("test" (values test-dir "caf3cabba9e"))
+               ("test" (values test-dir "caf3cabba9e" #f))
                (_      (values (channel-instance-checkout instance--no-deps)
-                               "abcde1234")))))
+                               "abcde1234" #f)))))
           (with-store store
             (let ((instances (latest-channel-instances store (list channel))))
               (and (eq? 2 (length instances))
@@ -155,11 +155,11 @@
                    (url "test")))
          (test-dir (channel-instance-checkout instance--with-dupes)))
     (mock ((guix git) update-cached-checkout
-           (lambda* (url #:key ref)
+           (lambda* (url #:key ref starting-commit)
              (match url
-               ("test" (values test-dir "caf3cabba9e"))
+               ("test" (values test-dir "caf3cabba9e" #f))
                (_      (values (channel-instance-checkout instance--no-deps)
-                               "abcde1234")))))
+                               "abcde1234" #f)))))
           (with-store store
             (let ((instances (latest-channel-instances store (list channel))))
               (and (= 2 (length instances))