fix crash on uninitialized unittracker for spinbuttons. fixes crash on changing major grid line number, possibly other random crashes

Fixed bugs:
  - https://launchpad.net/bugs/1229183

(bzr r12581)

2 files changed, 9 insertions, 7 deletions

diff --git a/src/ui/widget/spinbutton.cpp b/src/ui/widget/spinbutton.cpp
index 62c17f821..1114ff32b 100644
--- a/src/ui/widget/spinbutton.cpp
+++ b/src/ui/widget/spinbutton.cpp
@@ -65,7 +65,7 @@ int SpinButton::on_input(double* newvalue)
 
 bool SpinButton::on_my_focus_in_event(GdkEventFocus* /*event*/)
 {
-    on_focus_in_value = get_value();
+    _on_focus_in_value = get_value();
     return false; // do not consume the event
 }
 
@@ -92,7 +92,7 @@ bool SpinButton::on_my_key_press_event(GdkEventKey* event)
 
 void SpinButton::undo()
 {
-    set_value(on_focus_in_value);
+    set_value(_on_focus_in_value);
 }
 
 
diff --git a/src/ui/widget/spinbutton.h b/src/ui/widget/spinbutton.h
index c772fe2a2..812b5f515 100644
--- a/src/ui/widget/spinbutton.h
+++ b/src/ui/widget/spinbutton.h
@@ -38,7 +38,9 @@ class SpinButton : public Gtk::SpinButton
 public:
   SpinButton(double climb_rate = 0.0, guint digits = 0)
     : Gtk::SpinButton(climb_rate, digits),
-      _unit_menu(NULL)
+      _unit_menu(NULL),
+      _unit_tracker(NULL),
+      _on_focus_in_value(0.)
   {
       connect_signals();
   };
@@ -48,10 +50,11 @@ public:
   explicit SpinButton(Gtk::Adjustment& adjustment, double climb_rate = 0.0, guint digits = 0)
 #endif
     : Gtk::SpinButton(adjustment, climb_rate, digits),
-      _unit_menu(NULL)
+      _unit_menu(NULL),
+      _unit_tracker(NULL),
+      _on_focus_in_value(0.)
   {
       connect_signals();
-      _unit_tracker = NULL;
   };
 
   virtual ~SpinButton() {};
@@ -63,6 +66,7 @@ public:
 protected:
   UnitMenu *_unit_menu; /// Linked unit menu for unit conversion in entered expressions.
   UnitTracker *_unit_tracker; // Linked unit tracker for unit conversion in entered expressions.
+  double _on_focus_in_value;
 
   void connect_signals();
 
@@ -95,8 +99,6 @@ protected:
      */
     void undo();
 
-  double on_focus_in_value;
-
 private:
   // noncopyable
   SpinButton(const SpinButton&);