Add GnuTLS support for W32 and certificate and hostname verification in GnuTLS.

* src/gnutls.c: Renamed global_initialized to
gnutls_global_initialized.  Added internals for the
:verify-hostname-error, :verify-error, and :verify-flags
parameters of `gnutls-boot' and documented those parameters in the
docstring.  Start callback support.
(emacs_gnutls_handshake): Add Woe32 support. Retry handshake
unless a fatal error occured. Call gnutls_alert_send_appropriate
on error. Return error code.
(emacs_gnutls_write): Call emacs_gnutls_handle_error.
(emacs_gnutls_read): Likewise.
(Fgnutls_boot): Return handshake error code.
(emacs_gnutls_handle_error): New function.
(wsaerror_to_errno): Likewise.

* src/gnutls.h: Add GNUTLS_STAGE_CALLBACKS enum to denote we're in the
callbacks stage.

* src/w32.c (emacs_gnutls_pull): New function for GnuTLS on Woe32.
(emacs_gnutls_push): Likewise.

* src/w32.h (emacs_gnutls_pull): Add prototype.
(emacs_gnutls_push): Likewise.

1 files changed, 16 insertions, 0 deletions

diff --git a/src/process.c b/src/process.c
index d8851c56cf0..4253286196c 100644
--- a/src/process.c
+++ b/src/process.c
@@ -4532,6 +4532,22 @@ wait_reading_process_output (int time_limit, int microsecs, int read_kbd,
              &Available,
              (check_write ? &Writeok : (SELECT_TYPE *)0),
              (SELECT_TYPE *)0, &timeout);
+
+#ifdef HAVE_GNUTLS
+          /* GnuTLS buffers data internally.  In lowat mode it leaves
+             some data in the TCP buffers so that select works, but
+             with custom pull/push functions we need to check if some
+             data is available in the buffers manually.  */
+          if (nfds == 0 && 
+              wait_proc && wait_proc->gnutls_p /* Check for valid process.  */
+              /* Do we have pending data?  */
+              && gnutls_record_check_pending (wait_proc->gnutls_state) > 0)
+          {
+              nfds = 1;
+              /* Set to Available.  */
+              FD_SET (wait_proc->infd, &Available);
+          }
+#endif
         }
 
       xerrno = errno;