web: Client treats TLS "premature termination" error as EOF.

Fixes <https://bugs.gnu.org/39800>.
Reported by <franco.rcr@gmail.com>.

* module/web/client.scm (tls-wrap)[read!]: Catch 'gnutls-error around
'get-bytevector-some' call.

1 files changed, 12 insertions, 1 deletions

diff --git a/module/web/client.scm b/module/web/client.scm
index 67d926f8a..769f3ecfa 100644
--- a/module/web/client.scm
+++ b/module/web/client.scm
@@ -243,7 +243,18 @@ host name without trailing dot."
     ;; underlying socket.
     (let ((record (session-record-port session)))
       (define (read! bv start count)
-        (define read-bv (get-bytevector-some record))
+        (define read-bv
+          (catch 'gnutls-error
+            (lambda ()
+              (get-bytevector-some record))
+            (lambda (key err proc . rest)
+              ;; When responding to "Connection: close" requests, some
+              ;; servers close the connection abruptly after sending the
+              ;; response body, without doing a proper TLS connection
+              ;; termination.  Treat it as EOF.
+              (if (eq? err error/premature-termination)
+                  the-eof-object
+                  (apply throw key err proc rest)))))
         (if (eof-object? read-bv)
             0  ; read! returns 0 on eof-object
             (let ((read-bv-len (bytevector-length read-bv)))