Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/matplotlib/tests/test_backend_tk.py

@@ -0,0 +1,41 @@
+import pytest
+import numpy as np
+from matplotlib import pyplot as plt
+
+
+@pytest.mark.backend('TkAgg', skip_on_importerror=True)
+def test_blit():
+    from matplotlib.backends import _tkagg
+    def evil_blit(photoimage, aggimage, offsets, bboxptr):
+        data = np.asarray(aggimage)
+        height, width = data.shape[:2]
+        dataptr = (height, width, data.ctypes.data)
+        _tkagg.blit(
+            photoimage.tk.interpaddr(), str(photoimage), dataptr, offsets,
+            bboxptr)
+
+    fig, ax = plt.subplots()
+    for bad_boxes in ((-1, 2, 0, 2),
+                      (2, 0, 0, 2),
+                      (1, 6, 0, 2),
+                      (0, 2, -1, 2),
+                      (0, 2, 2, 0),
+                      (0, 2, 1, 6)):
+        with pytest.raises(ValueError):
+            evil_blit(fig.canvas._tkphoto,
+                      np.ones((4, 4, 4)),
+                      (0, 1, 2, 3),
+                      bad_boxes)
+
+
+@pytest.mark.backend('TkAgg', skip_on_importerror=True)
+def test_missing_back_button():
+    from matplotlib.backends.backend_tkagg import NavigationToolbar2Tk
+    class Toolbar(NavigationToolbar2Tk):
+        # only display the buttons we need
+        toolitems = [t for t in NavigationToolbar2Tk.toolitems if
+                     t[0] in ('Home', 'Pan', 'Zoom')]
+
+    fig = plt.figure()
+    # this should not raise
+    Toolbar(fig.canvas, fig.canvas.manager.window)