substitutes: Add #:keep-alive? keyword argument to download-nar.issue-70494

To be consistent with other procedures that make network requests.

* guix/substitutes.scm (download-nar): Add #:keep-alive? option.
* guix/scripts/substitute.scm (process-substitution/fallback,
process-substitution): Call download-nar with #:keep-alive? #t.

Change-Id: I83b27d0c3a0916d058fbbbeb7aa77dbb8a742768

1 files changed, 9 insertions, 2 deletions

diff --git a/guix/substitutes.scm b/guix/substitutes.scm
index 5089f3a6da..7c8f8cc973 100644
--- a/guix/substitutes.scm
+++ b/guix/substitutes.scm
@@ -462,7 +462,8 @@ again."
                        #:key deduplicate? print-build-trace?
                        (fetch-timeout %fetch-timeout)
                        prefer-fast-decompression?
-                       (open-connection-for-uri guix:open-connection-for-uri))
+                       (open-connection-for-uri guix:open-connection-for-uri)
+                       (keep-alive? #f))
   "Download the nar prescribed in NARINFO, which is assumed to be authentic
 and authorized, and write it to DESTINATION.  When DEDUPLICATE? is true, and
 if DESTINATION is in the store, deduplicate its files."
@@ -505,7 +506,7 @@ if DESTINATION is in the store, deduplicate its files."
                           (raise c))))
              (http-fetch uri #:text? #f
                          #:port port
-                         #:keep-alive? #t
+                         #:keep-alive? keep-alive?
                          #:buffered? #f)))))
       (else
        (raise
@@ -586,6 +587,12 @@ if DESTINATION is in the store, deduplicate its files."
       ;; Wait for the reporter to finish.
       (every (compose zero? cdr waitpid) pids)
 
+      ;; TODO The port should also be closed if the relevant HTTP response
+      ;; header is set, but http-fetch doesn't currently share that
+      ;; information
+      (unless keep-alive?
+        (close-port raw))
+
       (values expected
               (get-hash)))))