BUG: handle colorbar ticks with boundaries and NoNorm; closes #5673

lib/matplotlib/colorbar.py

@@ -580,7 +580,7 @@ def _ticker(self):
             else:
                 b = self._boundaries[self._inside]
                 locator = ticker.FixedLocator(b, nbins=10)
-        if isinstance(self.norm, colors.NoNorm):
+        if isinstance(self.norm, colors.NoNorm) and self.boundaries is None:
             intv = self._values[0], self._values[-1]
         else:
             intv = self.vmin, self.vmax

lib/matplotlib/tests/test_colorbar.py

@@ -282,6 +282,22 @@ def test_colorbar_closed_patch():
                      extend='neither', values=values)
 
 
+@cleanup
+def test_colorbar_ticks():
+    # test fix for #5673
+    fig, ax = plt.subplots()
+    x = np.arange(-3.0, 4.001)
+    y = np.arange(-4.0, 3.001)
+    X, Y = np.meshgrid(x, y)
+    Z = X * Y
+    clevs = np.array([-12, -5, 0, 5, 12], dtype=float)
+    colors = ['r', 'g', 'b', 'c']
+    cs = ax.contourf(X, Y, Z, clevs, colors=colors)
+    cbar = fig.colorbar(cs, ax=ax, extend='neither',
+                        orientation='horizontal', ticks=clevs)
+    assert len(cbar.ax.xaxis.get_ticklocs()) == len(clevs)
+
+
 if __name__ == '__main__':
     import nose
     nose.runmodule(argv=['-s', '--with-doctest'], exit=False)