[gnumeric] GUI: Fix crash on exit related to split panes.

[Morten Welinder <mortenw src gnome org>]

commit 4fec2df7dfd77330b8f19b295a93df92bcfc2396
Author: Morten Welinder <terra gnome org>
Date:   Tue May 27 18:38:11 2014 -0400

    GUI: Fix crash on exit related to split panes.

 ChangeLog      |    6 ++++++
 NEWS           |    1 +
 src/gnm-pane.c |    9 +++++++--
 3 files changed, 14 insertions(+), 2 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index db73ee4..4869f16 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2014-05-27  Morten Welinder  <terra gnome org>
+
+       * src/gnm-pane.c (gnm_pane_header_init): Hold references to
+       col/row canvas.  Fixes #730857.
+       (gnm_pane_dispose): Release references.
+
 2014-05-23  Morten Welinder <terra gnome org>
 
        * configure.ac: Post-release bump.
diff --git a/NEWS b/NEWS
index ad62193..10ec133 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,7 @@ Gnumeric 1.12.17
 
 Morten:
        * Fix UMR.  [#730727]
+       * Fix crash on exit.  [#730857]
 
 --------------------------------------------------------------------------
 Gnumeric 1.12.16
diff --git a/src/gnm-pane.c b/src/gnm-pane.c
index 8c0f7f0..3a4498a 100644
--- a/src/gnm-pane.c
+++ b/src/gnm-pane.c
@@ -851,11 +851,13 @@ gnm_pane_dispose (GObject *obj)
 
        if (pane->col.canvas != NULL) {
                gtk_widget_destroy (GTK_WIDGET (pane->col.canvas));
+               g_object_unref (pane->col.canvas);
                pane->col.canvas = NULL;
        }
 
        if (pane->row.canvas != NULL) {
                gtk_widget_destroy (GTK_WIDGET (pane->row.canvas));
+               g_object_unref (pane->row.canvas);
                pane->row.canvas = NULL;
        }
 
@@ -1044,6 +1046,9 @@ gnm_pane_class_init (GnmPaneClass *klass)
 GSF_CLASS (GnmPane, gnm_pane,
           gnm_pane_class_init, gnm_pane_init,
           GNM_SIMPLE_CANVAS_TYPE)
+#if 0
+;
+#endif
 
 static void
 gnm_pane_header_init (GnmPane *pane, SheetControlGUI *scg,
@@ -1063,10 +1068,10 @@ gnm_pane_header_init (GnmPane *pane, SheetControlGUI *scg,
        if (is_col_header) {
                if (sheet && sheet->text_is_rtl)
                        goc_canvas_set_direction (canvas, GOC_DIRECTION_RTL);
-               pane->col.canvas = canvas;
+               pane->col.canvas = g_object_ref_sink (canvas);
                pane->col.item = GNM_ITEM_BAR (item);
        } else {
-               pane->row.canvas = canvas;
+               pane->row.canvas = g_object_ref_sink (canvas);
                pane->row.item = GNM_ITEM_BAR (item);
        }