Fix bug produced on Transform tool state.

When use Scale Constrained (ALT+SHIFT) it was produced a division by zero.

diff --git a/synfig-studio/src/gtkmm/state_normal.cpp b/synfig-studio/src/gtkmm/state_normal.cpp
index c8ef101..7cd9b31 100644 (file)
--- a/synfig-studio/src/gtkmm/state_normal.cpp
+++ b/synfig-studio/src/gtkmm/state_normal.cpp
@@ -124,7 +124,7 @@ public:
        void refresh_cursor();
 
        bool get_rotate_flag()const { if(duck_dragger_) return duck_dragger_->rotate; else return false; }
-       void set_rotate_flag(bool x) { if(duck_dragger_ && x!=duck_dragger_->rotate) 
+       void set_rotate_flag(bool x) { if(duck_dragger_ && x!=duck_dragger_->rotate)
                                               {duck_dragger_->rotate=x; refresh_cursor();} }
 
        bool get_scale_flag()const { if(duck_dragger_) return duck_dragger_->scale; else return false; }
@@ -441,8 +441,12 @@ DuckDrag_Combo::duck_drag(Duckmatic* duckmatic, const synfig::Vector& vector)
                        }
                else
                {
-                       //vect[0]=vect[1]=vect.mag()*0.707106781;
-                       Real amount(vect.mag()/(drag_offset-center).mag());
+                       Real amount;
+                       if((drag_offset-center).mag() < EPSILON)
+                               amount = 1;
+                       else
+                               amount = vect.mag()/(drag_offset-center).mag();
+
                        vect[0]=vect[1]=amount;
                }
 
@@ -473,6 +477,7 @@ DuckDrag_Combo::duck_drag(Duckmatic* duckmatic, const synfig::Vector& vector)
                        p+=center;
                        (*iter)->set_trans_point(p, time);
                }
+
        }
 
        // then patch up the tangents for the vertices we've moved