01/10: Fix broken links to builds

[Christopher Baines]

cbaines pushed a commit to branch master
in repository data-service.

commit b5b89b3645e0868aa225926cff66602626b7a145
Author: Christopher Baines <mail@cbaines.net>
AuthorDate: Wed Oct 21 18:38:29 2020 +0100

    Fix broken links to builds
---
 guix-data-service/web/html-utils.scm | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/guix-data-service/web/html-utils.scm 
b/guix-data-service/web/html-utils.scm
index 5fa1ad4..660fcd3 100644
--- a/guix-data-service/web/html-utils.scm
+++ b/guix-data-service/web/html-utils.scm
@@ -70,7 +70,8 @@
    value))
 
 (define (build-url build-server-id build-server-build-id derivation-file-name)
-  (if (string? build-server-build-id)
+  (if (and (string? build-server-build-id)
+           (not (string-null? build-server-build-id)))
       (simple-format
        #f "/build-server/~A/build?build_server_build_id=~A"
        build-server-id