FIX: make colorbars for log normed contour plots have logscale

Author: jklymak

lib/matplotlib/colorbar.py

@@ -1180,7 +1180,11 @@ def _reset_locator_formatter_scale(self):
         self._minorlocator = None
         self._formatter = None
         self._minorformatter = None
-        if (self.boundaries is not None or
+        if (isinstance(self.mappable, contour.ContourSet) and
+                isinstance(self.norm, colors.LogNorm)):
+            # if contours have lognorm, give them a log scale...
+            self._set_scale('log')
+        elif (self.boundaries is not None or
                 isinstance(self.norm, colors.BoundaryNorm)):
             if self.spacing == 'uniform':
                 funcs = (self._forward_boundaries, self._inverse_boundaries)