[evolution-ews] Make use of SOUP_MESSAGE_IDEMPOTENT SoupMessage flag, if available

[Milan Crha <mcrha src gnome org>]

commit 5ce8972b2f634d549038e4909e0f143642b8ce22
Author: Milan Crha <mcrha redhat com>
Date:   Mon Aug 20 14:12:00 2012 +0200

    Make use of SOUP_MESSAGE_IDEMPOTENT SoupMessage flag, if available
    
    This is used to indicate that the message might be considered
    idempotent, regardless the method being used. The thing is that
    POST is not idempotent, thus each request means disconnect from
    the server and reconnect. This flag allows EWS to not reconnect
    that often.

 configure.ac                |   14 ++++++++++++++
 src/server/e-soap-message.c |    8 ++++++++
 2 files changed, 22 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 8d7a645..b4851df 100644
--- a/configure.ac
+++ b/configure.ac
@@ -175,6 +175,20 @@ dnl ****************************
 EVO_KRB5_SUPPORT
 
 dnl ****************************
+dnl Check for libsoup's SOUP_MESSAGE_IDEMPOTENT SoupMessage flag
+dnl ****************************
+AC_MSG_CHECKING([libsoup SOUP_MESSAGE_IDEMPOTENT flag])
+save_cflags=$CFLAGS; CFLAGS=$SOUP_CFLAGS
+save_libs=$LIBS; LIBS="$SOUP_LIBS"
+AC_LINK_IFELSE([AC_LANG_PROGRAM(
+	[[#include <libsoup/soup.h>]],
+	[[SoupMessageFlags flag; flag = SOUP_MESSAGE_IDEMPOTENT]])],
+	[AC_DEFINE(HAVE_SOUP_MESSAGE_IDEMPOTENT_FLAG, 1, [libsoup provides SOUP_MESSAGE_IDEMPOTENT flag]) ac_cv_have_smi=yes],[ac_cv_have_smi=no])
+CFLAGS=$save_cflags
+LIBS=$save_libs
+AC_MSG_RESULT([$ac_cv_have_smi])
+
+dnl ****************************
 dnl Expose version information
 dnl ****************************
 API_VERSION=1.2
diff --git a/src/server/e-soap-message.c b/src/server/e-soap-message.c
index c2a900a..f43adc5 100644
--- a/src/server/e-soap-message.c
+++ b/src/server/e-soap-message.c
@@ -3,6 +3,10 @@
  * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
  */
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
 #include <libedataserver/eds-version.h>
 
 #include <string.h>
@@ -103,6 +107,10 @@ e_soap_message_init (ESoapMessage *msg)
 	msg->priv->doc->standalone = FALSE;
 	msg->priv->doc->encoding = xmlCharStrdup ("UTF-8");
 	msg->priv->steal_fd = -1;
+
+#ifdef HAVE_SOUP_MESSAGE_IDEMPOTENT_FLAG
+	soup_message_set_flags (SOUP_MESSAGE (msg), SOUP_MESSAGE_IDEMPOTENT);
+#endif
 }
 
 static xmlNsPtr