[evolution-ews] Fix crasher in oal_response_cb().

[Matthew Barnes <mbarnes src gnome org>]

commit b96fcc0501bfa04a9c5a329af011a2b1140e19ed
Author: Matthew Barnes <mbarnes redhat com>
Date:   Fri Jul 6 10:20:51 2012 -0400

    Fix crasher in oal_response_cb().
    
    I introduced this in commit c85384779272821fcdf38383c8bc63891c88a04e.
    
    Accidentally changed "if (!data->oal_id)" to "if (data->oal_id != NULL)"
    when if should have been "if (data->oal_id == NULL)".
    
    Testing pointers with an negation operator (!p) is less readable than
    comparing to NULL explicitly (p == NULL).

 src/server/e-ews-connection.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/server/e-ews-connection.c b/src/server/e-ews-connection.c
index 2b68bf9..af6a02f 100644
--- a/src/server/e-ews-connection.c
+++ b/src/server/e-ews-connection.c
@@ -1933,7 +1933,7 @@ oal_response_cb (SoupSession *soup_session,
 
 	for (node = node->children; node; node = node->next) {
 		if (node->type == XML_ELEMENT_NODE && strcmp((gchar *) node->name, "OAL") == 0) {
-			if (data->oal_id != NULL) {
+			if (data->oal_id == NULL) {
 				EwsOAL *oal = g_new0 (EwsOAL, 1);
 
 				oal->id = get_property (node, "id");