[goocanvasmm] Correct null pointer conversion from Goocanvas::Canvas* to GooCanvas*.

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 50ff86bdb1d5314403cc500dc63692b7723118d5
Author: Kjell Ahlstedt <kjell ahlstedt bredband net>
Date:   Sun Jun 12 17:06:49 2011 +0200

    Correct null pointer conversion from Goocanvas::Canvas* to GooCanvas*.
    
    * codegen/m4/convert_libgoocanvasmm.m4: Use Glib::unwrap(x) instead of
    x->gobj(), avoiding a crash when x is 0. Bug #606357.

 ChangeLog                            |    7 +++++++
 codegen/m4/convert_libgoocanvasmm.m4 |    2 +-
 2 files changed, 8 insertions(+), 1 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index ac5057f..d42067b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2011-06-12  Kjell Ahlstedt  <kjell ahlstedt bredband net>
+
+	Correct null pointer conversion from Goocanvas::Canvas* to GooCanvas*.
+
+	* codegen/m4/convert_libgoocanvasmm.m4: Use Glib::unwrap(x) instead of
+	x->gobj(), avoiding a crash when x is 0. Bug #606357.
+
 1.90.4:
 
 2011-03-30  Murray Cumming  <murrayc murrayc com>
diff --git a/codegen/m4/convert_libgoocanvasmm.m4 b/codegen/m4/convert_libgoocanvasmm.m4
index 47cd2a4..ed47814 100644
--- a/codegen/m4/convert_libgoocanvasmm.m4
+++ b/codegen/m4/convert_libgoocanvasmm.m4
@@ -17,7 +17,7 @@ _CONVERSION(`gint',`GooCanvas::StyleValuesMask',`static_cast<GooCanvas::StyleVal
 
 _CONVERSION(`GtkWidget*',`Canvas*',`Glib::Wrap((GtkCanvas*)($3))')
 _CONVERSION(`GooCanvas*',`Canvas*',`Glib::wrap($3)')
-_CONVERSION(`Canvas*',`GooCanvas*',`($3)->gobj()')
+_CONVERSION(`Canvas*',`GooCanvas*',`Glib::unwrap($3)')
 #_CONVERSION(`GooCanvas*',`Canvas*',__RP2P)
 #_CONVERSION(`GooCanvas*',`const Canvas*',__RP2P)
 #_CONVERSION(`Canvas&',`GooCanvas*',__FR2PD)