channels: Dependencies listed in '.guix-channel' can have an introduction.

Suggested by Ricardo Wurmus and Simon Tournier.

* guix/channels.scm (sexp->channel-introduction): New procedure.
(read-channel-metadata): Use it.
(profile-channels)[sexp->channel-introduction]: Remove.
* tests/channels.scm ("latest-channel-instances, authenticate dependency"):
New test.
* doc/guix.texi (Channels)[Declaring Channel Dependencies]: Augment example.

1 files changed, 50 insertions, 0 deletions

diff --git a/tests/channels.scm b/tests/channels.scm
index 7e593b84c4..cde3b668fb 100644
--- a/tests/channels.scm
+++ b/tests/channels.scm
@@ -536,4 +536,54 @@
                                        #:keyring-reference-prefix "")
                  'failed)))))))
 
+(unless (gpg+git-available?) (test-skip 1))
+(test-equal "latest-channel-instances, authenticate dependency"
+  #t
+  ;; Make sure that a channel dependency that has an introduction is
+  ;; authenticated.  This test checks that an authentication error is raised
+  ;; as it should when authenticating the dependency.
+  (with-fresh-gnupg-setup (list %ed25519-public-key-file
+                                %ed25519-secret-key-file)
+    (with-temporary-git-repository dependency-directory
+        `((add ".guix-channel"
+               ,(object->string
+                 '(channel (version 0)
+                           (keyring-reference "master"))))
+          (add ".guix-authorizations"
+               ,(object->string
+                 `(authorizations (version 0) ())))
+          (add "signer.key" ,(call-with-input-file %ed25519-public-key-file
+                               get-string-all))
+          (commit "zeroth commit"
+                  (signer ,(key-fingerprint %ed25519-public-key-file)))
+          (add "foo.txt" "evil")
+          (commit "unsigned commit"))
+      (with-repository dependency-directory dependency
+        (let* ((commit0 (find-commit dependency "zeroth"))
+               (commit1 (find-commit dependency "unsigned"))
+               (intro   `(channel-introduction
+                          (version 0)
+                          (commit ,(commit-id-string commit0))
+                          (signer ,(openpgp-format-fingerprint
+                                    (openpgp-public-key-fingerprint
+                                     (read-openpgp-packet
+                                      %ed25519-public-key-file)))))))
+          (with-temporary-git-repository directory
+              `((add ".guix-channel"
+                     ,(object->string
+                       `(channel (version 0)
+                                 (dependencies
+                                  (channel
+                                   (name test-channel)
+                                   (url ,dependency-directory)
+                                   (introduction ,intro))))))
+                (commit "single commit"))
+            (let ((channel (channel (name 'test) (url directory))))
+              (guard (c ((unsigned-commit-error? c)
+                         (oid=? (git-authentication-error-commit c)
+                                (commit-id commit1))))
+                (with-store store
+                  (latest-channel-instances store (list channel))
+                  'failed)))))))))
+
 (test-end "channels")