[libsoup/wip/tpopela/negotiate] soup-auth: Introduce the can_authenticate virtual method

[Tomas Popela <tpopela src gnome org>]

commit 0b34a7b1618459405d8e0ad05bda11a295742e55
Author: Tomas Popela <tpopela redhat com>
Date:   Fri Feb 19 14:07:25 2016 +0100

    soup-auth: Introduce the can_authenticate virtual method
    
    It tests if the SoupAuth object is able to authenticate by providing credentials
    to the soup_auth_authenticate() method. For every authentication method it is
    true, but not for the soup-auth-negotiate where authentication with username and
    password is not allowed.

 libsoup/soup-auth-manager.c   |    7 +++----
 libsoup/soup-auth-negotiate.c |    7 +++++++
 libsoup/soup-auth.c           |   26 ++++++++++++++++++++++++++
 libsoup/soup-auth.h           |    4 ++++
 4 files changed, 40 insertions(+), 4 deletions(-)
---
diff --git a/libsoup/soup-auth-manager.c b/libsoup/soup-auth-manager.c
index b38c6b5..9455265 100644
--- a/libsoup/soup-auth-manager.c
+++ b/libsoup/soup-auth-manager.c
@@ -13,7 +13,6 @@
 
 #include "soup-auth-manager.h"
 #include "soup.h"
-#include "soup-auth-negotiate.h"
 #include "soup-connection-auth.h"
 #include "soup-message-private.h"
 #include "soup-message-queue.h"
@@ -469,6 +468,9 @@ authenticate_auth (SoupAuthManager *manager, SoupAuth *auth,
        SoupAuthManagerPrivate *priv = manager->priv;
        SoupURI *uri;
 
+       if (!soup_auth_can_authenticate (auth))
+               return;
+
        if (proxy) {
                SoupMessageQueue *queue;
                SoupMessageQueueItem *item;
@@ -486,9 +488,6 @@ authenticate_auth (SoupAuthManager *manager, SoupAuth *auth,
        } else
                uri = soup_message_get_uri (msg);
 
-       if (SOUP_IS_AUTH_NEGOTIATE (auth))
-               return;
-
        /* If a password is specified explicitly in the URI, use it
         * even if the auth had previously already been authenticated.
         */
diff --git a/libsoup/soup-auth-negotiate.c b/libsoup/soup-auth-negotiate.c
index c2bc135..37caaa5 100644
--- a/libsoup/soup-auth-negotiate.c
+++ b/libsoup/soup-auth-negotiate.c
@@ -228,6 +228,12 @@ soup_auth_negotiate_is_authenticated (SoupAuth *auth)
        return priv->is_authenticated;
 }
 
+static gboolean
+soup_auth_negotiate_can_authenticate (SoupAuth *auth)
+{
+       return FALSE;
+}
+
 static char *
 soup_auth_negotiate_get_connection_authorization (SoupConnectionAuth *auth,
                                                  SoupMessage *msg,
@@ -270,6 +276,7 @@ soup_auth_negotiate_class_init (SoupAuthNegotiateClass *auth_negotiate_class)
        auth_class->get_protection_space = soup_auth_negotiate_get_protection_space;
        auth_class->authenticate = soup_auth_negotiate_authenticate;
        auth_class->is_authenticated = soup_auth_negotiate_is_authenticated;
+       auth_class->can_authenticate = soup_auth_negotiate_can_authenticate;
 
        conn_auth_class->create_connection_state = soup_auth_negotiate_create_connection_state;
        conn_auth_class->free_connection_state = soup_auth_negotiate_free_connection_state;
diff --git a/libsoup/soup-auth.c b/libsoup/soup-auth.c
index 49d8df2..79aa7c3 100644
--- a/libsoup/soup-auth.c
+++ b/libsoup/soup-auth.c
@@ -129,6 +129,11 @@ soup_auth_get_property (GObject *object, guint prop_id,
        }
 }
 
+static gboolean
+auth_can_authenticate (SoupAuth *auth)
+{
+       return TRUE;
+}
 
 static void
 soup_auth_class_init (SoupAuthClass *auth_class)
@@ -137,6 +142,8 @@ soup_auth_class_init (SoupAuthClass *auth_class)
 
        g_type_class_add_private (auth_class, sizeof (SoupAuthPrivate));
 
+       auth_class->can_authenticate = auth_can_authenticate;
+
        object_class->finalize     = soup_auth_finalize;
        object_class->set_property = soup_auth_set_property;
        object_class->get_property = soup_auth_get_property;
@@ -491,6 +498,25 @@ soup_auth_is_ready (SoupAuth    *auth,
 }
 
 /**
+ * soup_auth_can_authenticate:
+ * @auth: a #SoupAuth
+ *
+ * Tests if @auth is able to authenticate by providing credentials to the
+ * soup_auth_authenticate().
+ *
+ * Return value: %TRUE if @auth is able to accept credentials.
+ *
+ * Since: 2.54
+ **/
+gboolean
+soup_auth_can_authenticate (SoupAuth *auth)
+{
+       g_return_val_if_fail (SOUP_IS_AUTH (auth), FALSE);
+
+       return SOUP_AUTH_GET_CLASS (auth)->can_authenticate (auth);
+}
+
+/**
  * soup_auth_get_protection_space:
  * @auth: a #SoupAuth
  * @source_uri: the URI of the request that @auth was generated in
diff --git a/libsoup/soup-auth.h b/libsoup/soup-auth.h
index 7c56e67..fbf6616 100644
--- a/libsoup/soup-auth.h
+++ b/libsoup/soup-auth.h
@@ -48,6 +48,8 @@ typedef struct {
        gboolean     (*is_ready)             (SoupAuth      *auth,
                                              SoupMessage   *msg);
 
+       gboolean     (*can_authenticate)     (SoupAuth      *auth);
+
        /* Padding for future expansion */
        void (*_libsoup_reserved2) (void);
        void (*_libsoup_reserved3) (void);
@@ -92,6 +94,8 @@ gboolean    soup_auth_is_authenticated      (SoupAuth      *auth);
 SOUP_AVAILABLE_IN_2_42
 gboolean    soup_auth_is_ready              (SoupAuth      *auth,
                                             SoupMessage   *msg);
+SOUP_AVAILABLE_IN_2_54
+gboolean    soup_auth_can_authenticate      (SoupAuth      *auth);
 
 SOUP_AVAILABLE_IN_2_4
 char       *soup_auth_get_authorization     (SoupAuth      *auth,