EMFolderTree: Store an EMailBackend instead of an EMailSession.

All this so EMFolderTree can submit EActivity instances for async ops.
You can obtain an EMailSession from an EMailBackend, but not vice versa.

Creates lots of pretty ripples in the mail code, but ultimately reduces
complexity.  So it's a code cleanup of sorts.

1 files changed, 3 insertions, 4 deletions

diff --git a/mail/importers/evolution-mbox-importer.c b/mail/importers/evolution-mbox-importer.c
index 9c251027e3..174c34b7a0 100644
--- a/mail/importers/evolution-mbox-importer.c
+++ b/mail/importers/evolution-mbox-importer.c
@@ -82,18 +82,16 @@ mbox_getwidget (EImport *ei, EImportTarget *target, EImportImporter *im)
 {
 	EShell *shell;
 	EShellBackend *shell_backend;
-	EMailSession *session;
 	GtkWindow *window;
 	GtkWidget *hbox, *w;
 	GtkLabel *label;
 	gchar *select_uri = NULL;
 
-	/* XXX Dig up the EMailSession from the default EShell.
+	/* XXX Dig up the mail backend from the default EShell.
 	 *     Since the EImport framework doesn't allow for user
 	 *     data, I don't see how else to get to it. */
 	shell = e_shell_get_default ();
 	shell_backend = e_shell_get_backend_by_name (shell, "mail");
-	session = e_mail_backend_get_session (E_MAIL_BACKEND (shell_backend));
 
 	/* preselect the folder selected in a mail view */
 	window = e_shell_get_active_window (shell);
@@ -130,7 +128,8 @@ mbox_getwidget (EImport *ei, EImportTarget *target, EImportImporter *im)
 	label = GTK_LABEL (w);
 
 	w = em_folder_selection_button_new (
-		session, _("Select folder"),
+		E_MAIL_BACKEND (shell_backend),
+		_("Select folder"),
 		_("Select folder to import into"));
 	gtk_label_set_mnemonic_widget (label, w);
 	em_folder_selection_button_set_selection (