mq-impl/stream: Handle ECONNRESET gracefully.

The otherwise failing test will be added in the next commit.

* gnu/gnunet/mq-impl/stream.scm
  (handle-input!): Handle ECONNRESET with a input:regular-end-of-file
  error.
  (handle-input!)[return/thunked]: New procedure.
  (handle-input!)[return/overly-small,return/premature-eof,return/done-eof]:
  Thunk.

1 files changed, 19 insertions, 7 deletions

diff --git a/gnu/gnunet/mq-impl/stream.scm b/gnu/gnunet/mq-impl/stream.scm
index 72cd59c..df12cb6 100644
--- a/gnu/gnunet/mq-impl/stream.scm
+++ b/gnu/gnunet/mq-impl/stream.scm
@@ -75,7 +75,7 @@
           (only (guile)
                 error define* identity define-values
                 EACCES ENOENT ENOTDIR ELOOP ENAMETOOLONG EAGAIN ECONNREFUSED
-                EPROTOTYPE EPIPE
+                EPROTOTYPE EPIPE ECONNRESET
                 PF_UNIX SOCK_STREAM F_GETFD F_SETFD F_GETFL F_SETFL FD_CLOEXEC
                 O_NONBLOCK AF_UNIX
                 socket connect fcntl force-output close-port
@@ -133,7 +133,8 @@ When the end-of-file has been reached, inject the error
 happened while inside a (partial) message, inject
 @code{input:premature-end-of-file} instead.
 
-In case of an I/O error, TODO.
+@code{ECONNRESET} is treated as @code{input:regular-end-of-file}.
+This might or might not be correct.  In case of an I/O error, TODO.
 
 In these exceptional cases, the call to this procedure also returns
 after injecting the error. TODO closing message queues."
@@ -144,14 +145,25 @@ after injecting the error. TODO closing message queues."
                  ;; TODO: this allocates memory
                  (slice/read-only
                   (bv-slice/read-write bv offset length))))
+             ;; Thunk the call to 'inject-error!' such that
+             ;; the exception handler is only active for the call to
+             ;; 'add-from-port!' and not for the call to 'inject-error!'.
+             (! (return/thunked . stuff)
+                (lambda () (apply return stuff)))
              (! (return/overly-small type size)
-                (return 'input:overly-small type size))
+                (return/thunked 'input:overly-small type size))
              (! (return/premature-eof)
-                (return 'input:premature-end-of-file))
+                (return/thunked 'input:premature-end-of-file))
              (! (return/done-eof)
-                (return 'input:regular-end-of-file)))
-            (add-from-port! tok input handle/message return/overly-small
-                            return/done-eof return/premature-eof)))
+                (return/thunked 'input:regular-end-of-file)))
+            ;; Prevent ‘In procedure fport_read: Connection reset by peer’
+            ;; in tests/network-size.scm.  XXX can this also happen in
+            ;; 'handle-output!'?
+            ((guard (c ((and (eq? 'system-error (exception-kind c))
+                             (= ECONNRESET (car (list-ref (exception-args c) 3))))
+                        (return/done-eof)))
+               (add-from-port! tok input handle/message return/overly-small
+                               return/done-eof return/premature-eof)))))
 
     (define (handle-output! mq output wait!)
       "Keep sending message envelopes over the output port @var{output}.