Bug 647698 - Selected calendar doesnt authenticate after offline/online

When I wrote e_load_cal_source_async() it didn't occur to me that a
calendar backend may emit "auth-required" after the initial connection
attempt.  And because I was passing the allocated context data for the
asynchronous load operation to e_cal_set_auth_func(), meaning the data
gets freed at the end of the load operation, I was then calling
e_cal_set_auth_func(cal, NULL, NULL) after the initial authentication
was complete so that the ECal would not try to access the freed context
data after the load operation finished.

But that turned out to break the case of switching to offline mode, then
back to online mode.  Most calendar backends need to re-authenticate when
they come back online.

This commit instead passes data to the authentication function by way of
g_object_set_data_full() so that the authentication function can be left
in place for the duration of the ECal instance.

Note that e_cal_set_auth_func() lacks a GDestroyNotify argument for the
user data passed to it, which rules out passing any kind of allocated
data structure.  This is an API design flaw, in my opinion.  But
g_object_set_data_full() *does* take a GDestroyNotify argument.

1 files changed, 39 insertions, 17 deletions

diff --git a/calendar/common/authentication.c b/calendar/common/authentication.c
index 286b7d6c46..ddcc0ffbd6 100644
--- a/calendar/common/authentication.c
+++ b/calendar/common/authentication.c
@@ -131,7 +131,6 @@ typedef struct {
 	icaltimezone *default_zone;
 
 	/* Authentication Details */
-	gchar *auth_uri;
 	gchar *auth_component;
 } LoadContext;
 
@@ -147,7 +146,6 @@ load_cal_source_context_free (LoadContext *context)
 	if (context->cancellable != NULL)
 		g_object_unref (context->cancellable);
 
-	g_free (context->auth_uri);
 	g_free (context->auth_component);
 
 	g_slice_free (LoadContext, context);
@@ -177,28 +175,39 @@ static gchar *
 load_cal_source_authenticate (ECal *cal,
                               const gchar *prompt,
                               const gchar *uri,
-                              LoadContext *context)
+                              gpointer not_used)
 {
+	const gchar *auth_component;
 	const gchar *title;
 	gboolean remember;  /* not used */
+	GtkWindow *parent;
 	gchar *password;
 
+	/* XXX Dig up authentication info embedded in the ECal instance.
+	 * (See load_cal_source_thread() for an explanation of why.) */
+	auth_component = g_object_get_data (G_OBJECT (cal), "auth-component");
+	g_return_val_if_fail (auth_component != NULL, NULL);
+
+	parent = g_object_get_data (G_OBJECT (cal), "parent-window");
+
 	/* Remember the URI so we don't have to reconstruct it if
 	 * authentication fails and we have to forget the password. */
-	g_free (context->auth_uri);
-	context->auth_uri = g_strdup (uri);
+	g_object_set_data_full (
+		G_OBJECT (cal),
+		"auth-uri", g_strdup (uri),
+		(GDestroyNotify) g_free);
 
 	/* XXX Dialog windows should not have titles. */
 	title = "";
 
-	password = e_passwords_get_password (context->auth_component, uri);
+	password = e_passwords_get_password (auth_component, uri);
 
 	if (password == NULL)
 		password = e_passwords_ask_password (
-			title, context->auth_component, uri,
+			title, auth_component, uri,
 			prompt, E_PASSWORDS_REMEMBER_FOREVER |
 			E_PASSWORDS_SECRET | E_PASSWORDS_ONLINE,
-			&remember, context->parent);
+			&remember, parent);
 
 	return password;
 }
@@ -233,20 +242,28 @@ load_cal_source_thread (GSimpleAsyncResult *simple,
 		return;
 	}
 
-	/* XXX Why doesn't EBook have something like this? */
+	/* XXX e_cal_set_auth_func() does not take a GDestroyNotify callback
+	 *     for the 'user_data' argument, which makes the argument rather
+	 *     useless.  So instead, we'll embed the information needed by
+	 *     the authentication callback directly into the ECal instance
+	 *     using g_object_set_data_full(). */
+	g_object_set_data_full (
+		G_OBJECT (cal), "auth-component",
+		g_strdup (context->auth_component),
+		(GDestroyNotify) g_free);
+	if (context->parent != NULL)
+		g_object_set_data_full (
+			G_OBJECT (cal), "parent-window",
+			g_object_ref (context->parent),
+			(GDestroyNotify) g_object_unref);
+
 	e_cal_set_auth_func (
-		cal, (ECalAuthFunc)
-		load_cal_source_authenticate, context);
+		cal, (ECalAuthFunc) load_cal_source_authenticate, NULL);
 
 try_again:
 	if (!e_cal_open (cal, FALSE, &error))
 		goto fail;
 
-	/* We should be authenticated now if we're going to be,
-	 * so remove the authentication callback so it doesn't
-	 * get triggered after we free the load context. */
-	e_cal_set_auth_func (cal, NULL, NULL);
-
 	if (g_cancellable_set_error_if_cancelled (cancellable, &error)) {
 		g_simple_async_result_set_from_error (simple, error);
 		g_object_unref (cal);
@@ -265,8 +282,13 @@ fail:
 	if (g_error_matches (
 		error, E_CALENDAR_ERROR,
 		E_CALENDAR_STATUS_AUTHENTICATION_FAILED)) {
+		const gchar *auth_uri;
+
+		/* Retrieve the URI set by the authentication function. */
+		auth_uri = g_object_get_data (G_OBJECT (cal), "auth-uri");
+
 		e_passwords_forget_password (
-			context->auth_component, context->auth_uri);
+			context->auth_component, auth_uri);
 		g_clear_error (&error);
 		goto try_again;