progress: Do not display the last 0B transfer when size is unknown.

* guix/progress.scm (display-download-progress): Don't display anything when
both SIZE and TRANSFERRED are null.

1 files changed, 14 insertions, 11 deletions

diff --git a/guix/progress.scm b/guix/progress.scm
index 7a25f11bd4..65080bcf24 100644
--- a/guix/progress.scm
+++ b/guix/progress.scm
@@ -212,17 +212,20 @@ throughput."
                                     (current-terminal-columns))
                  log-port)
         (force-output log-port))
-      (let* ((throughput (/ transferred elapsed))
-             (left       (format #f " ~a" file))
-             (right      (format #f "~a/s ~a | ~a transferred"
-                                 (byte-count->string throughput)
-                                 (seconds->string elapsed)
-                                 (byte-count->string transferred))))
-        (erase-current-line log-port)
-        (display (string-pad-middle left right
-                                    (current-terminal-columns))
-                 log-port)
-        (force-output log-port))))
+      ;; If we don't know the total size, the last transfer will have a 0B
+      ;; size.  Don't display it.
+      (unless (zero? transferred)
+        (let* ((throughput (/ transferred elapsed))
+               (left       (format #f " ~a" file))
+               (right      (format #f "~a/s ~a | ~a transferred"
+                                   (byte-count->string throughput)
+                                   (seconds->string elapsed)
+                                   (byte-count->string transferred))))
+          (erase-current-line log-port)
+          (display (string-pad-middle left right
+                                      (current-terminal-columns))
+                   log-port)
+          (force-output log-port)))))
 
 (define %progress-interval
   ;; Default interval between subsequent outputs for rate-limited displays.