store: 'export-paths' doesn't export references of the given files.

This fixes a regression introduced in
99fbddf9a623757e39d88bfb431f8f7d6f24b75b ("store: Change 'export-paths'
to always export in topological order.")

* guix/store.scm (export-paths): Define 'ordered' variable.  Iterate
  over it.
* tests/store.scm ("export/import paths, ensure topological order"): Add
  'file0'.  Adjust accordingly.

2 files changed, 11 insertions, 3 deletions

diff --git a/guix/store.scm b/guix/store.scm
index 54ed31cbbc..e92e159ff4 100644
--- a/guix/store.scm
+++ b/guix/store.scm
@@ -734,8 +734,13 @@ is raised if the set of paths read from PORT is not signed (as per
 (define* (export-paths server paths port #:key (sign? #t))
   "Export the store paths listed in PATHS to PORT, in topological order,
 signing them if SIGN? is true."
+  (define ordered
+    ;; Sort PATHS, but don't include their references.
+    (filter (cut member <> paths)
+            (topologically-sorted server paths)))
+
   (let ((s (nix-server-socket server)))
-    (let loop ((paths (topologically-sorted server paths)))
+    (let loop ((paths ordered))
       (match paths
         (()
          (write-int 0 port))
diff --git a/tests/store.scm b/tests/store.scm
index 7b0f3249d2..cc76ea5500 100644
--- a/tests/store.scm
+++ b/tests/store.scm
@@ -399,7 +399,9 @@ Deriver: ~a~%"
                              files)))))))
 
 (test-assert "export/import paths, ensure topological order"
-  (let* ((file1 (add-text-to-store %store "foo" (random-text)))
+  (let* ((file0 (add-text-to-store %store "baz" (random-text)))
+         (file1 (add-text-to-store %store "foo" (random-text)
+                                   (list file0)))
          (file2 (add-text-to-store %store "bar" (random-text)
                                    (list file1)))
          (files (list file1 file2))
@@ -412,9 +414,10 @@ Deriver: ~a~%"
          (bytevector=? dump1 dump2)
          (let* ((source   (open-bytevector-input-port dump1))
                 (imported (import-paths %store source)))
+           ;; DUMP1 should contain exactly FILE1 and FILE2, not FILE0.
            (and (equal? imported (list file1 file2))
                 (every file-exists? files)
-                (null? (references %store file1))
+                (equal? (list file0) (references %store file1))
                 (equal? (list file1) (references %store file2)))))))
 
 (test-assert "import corrupt path"