[gnumeric] Sheet: fix chain in constructed method.

[Morten Welinder <mortenw src gnome org>]

commit 1d8b33e10e2de92369f1e99d3d4694fd15b557ec
Author: Morten Welinder <terra gnome org>
Date:   Tue May 24 22:10:43 2011 -0400

    Sheet: fix chain in constructed method.

 ChangeLog   |    3 +++
 src/sheet.c |    3 ++-
 2 files changed, 5 insertions(+), 1 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 24b1fe6..71c35ae 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2011-05-24  Morten Welinder  <terra gnome org>
 
+	* src/sheet.c (gnm_sheet_constructed): Don't chain up before
+	actually checking that the parent has the method.
+
 	* src/wbc-gtk-edit.c (wbcg_auto_completing): Unused.  Remove.
 
 2011-05-23  Morten Welinder  <terra gnome org>
diff --git a/src/sheet.c b/src/sheet.c
index 0c1ab57..c44e21f 100644
--- a/src/sheet.c
+++ b/src/sheet.c
@@ -702,7 +702,8 @@ gnm_sheet_constructed (GObject *obj)
 
 	sheet_scale_changed (sheet, TRUE, TRUE);
 
-	parent_class->constructed (obj);
+	if (parent_class->constructed)
+		parent_class->constructed (obj);
 }
 
 static guint