Fix the same bug as the last commit, but better. Deleting from a set doesn't invalid...

git-svn-id: http://svn.voria.com/code@1571 1f10aa63-cdf2-0310-b900-c93c546f37ac

diff --git a/synfig-core/trunk/src/synfig/canvas.cpp b/synfig-core/trunk/src/synfig/canvas.cpp
index 8cf1f20..66d3d06 100644 (file)
--- a/synfig-core/trunk/src/synfig/canvas.cpp
+++ b/synfig-core/trunk/src/synfig/canvas.cpp
@@ -90,32 +90,24 @@ Canvas::on_changed()
 
 Canvas::~Canvas()
 {
-       bool keep_going = true;
-
        // we were having a crash where pastecanvas layers were still
        // refering to a canvas after it had been destroyed;  this code
        // will stop the pastecanvas layers from refering to the canvas
        // before the canvas is destroyed
 
        // the set_sub_canvas(0) ends up deleting the parent-child link,
-       // which modifies the set we're iterating through, invalidating
-       // the set iterator.  the outer while loop makes sure that we
-       // recreate the set iterator each time the set itself is modified
-       while (keep_going)
+       // which deletes the current element from the set we're iterating
+       // through, so we have to make sure we've incremented the iterator
+       // before we mess with the pastecanvas
+       std::set<Node*>::iterator iter = parent_set.begin();
+       while (iter != parent_set.end())
        {
-               keep_going = false;             // only keep going if we find a pastecanvas parent to clear
-               for (std::set<Node*>::iterator iter = parent_set.begin(); iter != parent_set.end(); iter++)
-               {
-                       Layer_PasteCanvas* paste_canvas = dynamic_cast<Layer_PasteCanvas*>(*iter);
-                       if(paste_canvas)
-                       {
-                               paste_canvas->set_sub_canvas(0);
-                               keep_going = true;
-                               break;                  // out of the for loop to the while loop
-                       }
-                       else
-                               warning("destroyed canvas has a parent that is not a pastecanvas - please report if repeatable");
-               }
+               Layer_PasteCanvas* paste_canvas = dynamic_cast<Layer_PasteCanvas*>(*iter);
+               iter++;
+               if(paste_canvas)
+                       paste_canvas->set_sub_canvas(0);
+               else
+                       warning("destroyed canvas has a parent that is not a pastecanvas - please report if repeatable");
        }
 
        //if(is_inline() && parent_) assert(0);