diff -r 5214b33f954d -r a70cee06ae9c gui/graph_displayer_canvas-zoom.cc
--- a/gui/graph_displayer_canvas-zoom.cc	Fri Nov 04 17:44:13 2005 +0000
+++ b/gui/graph_displayer_canvas-zoom.cc	Fri Nov 04 19:07:15 2005 +0000
@@ -16,34 +16,36 @@
 
 void GraphDisplayerCanvas::zoomFit()
 {
+  updateScrollRegion();
+
   // get the height and width of the canvas
   Gtk::Allocation a = get_allocation();
   int aw = a.get_width();
   int ah = a.get_height();
-  // add some space
-  aw -= 5; if (aw < 0) aw = 0;
-  ah -= 5; if (ah < 0) ah = 0;
 
   // get the bounding box of the graph
-  double wx1, wy1, wx2, wy2;
-  Gnome::Canvas::Item* pCanvasItem = root();
-  pCanvasItem->get_bounds(wx1, wy1, wx2, wy2);
+  update_now();
+  double x1, y1, x2, y2;
+  root()->get_bounds(x1, y1, x2, y2);
 
   // fit the graph to the window
-  double ppu1 = (double) aw / fabs(wx2 - wx1);
-  double ppu2 = (double) ah / fabs(wy2 - wy1);
+  double ppu1 = (double) aw / fabs(x2 - x1);
+  double ppu2 = (double) ah / fabs(y2 - y1);
   set_pixels_per_unit((ppu1 < ppu2) ? ppu1 : ppu2);
 }
 
 void GraphDisplayerCanvas::zoom100()
 {
+  updateScrollRegion();
   set_pixels_per_unit(1.0);
 }
 
 void GraphDisplayerCanvas::updateScrollRegion()
 {
-  double wx1, wy1, wx2, wy2;
-  Gnome::Canvas::Item* pCanvasItem = root();
-  pCanvasItem->get_bounds(wx1, wy1, wx2, wy2);
-  set_scroll_region(wx1, wy1, wx2, wy2);
+  // get_bounds() yields something sane only when no updates are pending
+  // and it returns a sufficient, not an exact bounding box
+  update_now();
+  double x1, y1, x2, y2;
+  root()->get_bounds(x1, y1, x2, y2);
+  set_scroll_region(x1, y1, x2, y2);
 }