[gnome-panel/wip/geiger/geometry] panel-struts: avoid negative strut_start

[Sebastian Geiger <segeiger src gnome org>]

commit 8663e9d9fa3890cc5093557c1ff6342c2007f435
Author: Sebastian Geiger <sbastig gmx net>
Date:   Sun Feb 18 21:50:14 2018 +0100

    panel-struts: avoid negative strut_start

 gnome-panel/panel-struts.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)
---
diff --git a/gnome-panel/panel-struts.c b/gnome-panel/panel-struts.c
index b6c9ad1..5d737e4 100644
--- a/gnome-panel/panel-struts.c
+++ b/gnome-panel/panel-struts.c
@@ -143,8 +143,13 @@ panel_struts_allocation_overlapped (PanelStrut   *strut,
                        *moved_down = TRUE;
                        break;
                case PANEL_ORIENTATION_BOTTOM:
-                       if (!*moved_down)
+                       if (!*moved_down) {
                                geometry->y = overlap_y1 - geometry->height;
+                               if (geometry->y < 0) {
+                                       geometry->height += geometry->y;
+                                       geometry->y = 0;
+                               }
+                       }
                        else if (overlap_y1 > geometry->y)
                                geometry->height = overlap_y1 - geometry->y;
                        else