[devhelp] BookTree: add FIXME comment

[Sébastien Wilmet <swilmet src gnome org>]

commit c22dcdfc9b40ae1ea9488b49d1bb28ba99fb2eff
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Fri Jul 7 16:33:37 2017 +0200

    BookTree: add FIXME comment

 src/dh-book-tree.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/dh-book-tree.c b/src/dh-book-tree.c
index 9263d36..2231b15 100644
--- a/src/dh-book-tree.c
+++ b/src/dh-book-tree.c
@@ -873,6 +873,9 @@ dh_book_tree_select_uri (DhBookTree  *tree,
         if (gtk_tree_selection_iter_is_selected (selection, &data.iter))
                 return;
 
+        /* FIXME: it's strange to block the signal here. The signal handler
+         * should probably be blocked in DhWindow instead.
+         */
         g_signal_handlers_block_by_func (selection,
                                          book_tree_selection_changed_cb,
                                          tree);