From: Noam Postavsky <npostavs@gmail.com>
Date: Mon, 6 May 2019 23:55:17 +0000 (-0400)
Subject: Handle GNUTLS_E_AGAIN in emacs_gnutls_read (Bug#34341)
X-Git-Tag: emacs-26.2.90~57
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=202ff53da267f9fa15f438e9c38603bbead6e890;p=emacs.git

Handle GNUTLS_E_AGAIN in emacs_gnutls_read (Bug#34341)

Don't merge to master, this has already been fixed there by 2019-01-15
"Fix unlikely races with GnuTLS, datagrams".
* src/gnutls.c (emacs_gnutls_read): Similar to emacs_gnutls_write,
when gnutls_record_recv returns GNUTLS_E_AGAIN set errno to EGAIN.
---

diff --git a/src/gnutls.c b/src/gnutls.c
index 3c16b6c9c31..b724c3592d0 100644
--- a/src/gnutls.c
+++ b/src/gnutls.c
@@ -753,8 +753,15 @@ emacs_gnutls_read (struct Lisp_Process *proc, char *buf, ptrdiff_t nbyte)
     /* The peer closed the connection. */
     return 0;
   else if (emacs_gnutls_handle_error (state, rtnval))
-    /* non-fatal error */
-    return -1;
+    {
+      /* If we get GNUTLS_E_AGAIN, then set errno appropriately so that
+         wait_reading_process_output retries the correct way instead of
+         erroring out.  */
+      if (rtnval == GNUTLS_E_AGAIN)
+        errno = EAGAIN;
+      /* non-fatal error */
+      return -1;
+    }
   else {
     /* a fatal error occurred */
     return 0;