[balsa/popover] balsa-index: Improve popup positioning at pointer

[Peter Bloomfield <peterb src gnome org>]

commit 0abab52aef2eb91ea83107a9a55c549f9409593c
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Thu May 21 17:30:35 2020 -0400

    balsa-index: Improve popup positioning at pointer

 src/balsa-index.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
---
diff --git a/src/balsa-index.c b/src/balsa-index.c
index 6c329d1ce..815afb8ab 100644
--- a/src/balsa-index.c
+++ b/src/balsa-index.c
@@ -2087,7 +2087,13 @@ bndx_do_popup(BalsaIndex * index, GdkEventButton * event)
     gtk_widget_get_allocation(GTK_WIDGET(index), &allocation);
     if (event != NULL && gdk_event_triggers_context_menu((GdkEvent *) event)) {
         /* Pop up to the right of the pointer */
-        allocation.width = event->x;
+        gtk_tree_view_convert_bin_window_to_widget_coords(GTK_TREE_VIEW(index),
+                                                          (gint) event->x,
+                                                          (gint) event->y,
+                                                          &allocation.x,
+                                                          &allocation.y);
+        allocation.width = 0;
+        allocation.height = 0;
     } else {
         /* Pop up to the right of the "From" column */
         allocation.width = balsa_app.index_num_width +