Merge pull request #18886 from jklymak/backport-18860

QuLogic · web-flow · commit b65885c17025 · 2020-11-04T00:49:00.000-05:00
Backport #18860 on branch v3.3.x
diff --git a/lib/matplotlib/colorbar.py b/lib/matplotlib/colorbar.py
@@ -788,6 +788,9 @@ def _add_solids(self, X, Y, C):
         Draw the colors using `~.axes.Axes.pcolormesh`;
         optionally add separators.
         """
+        if C.shape[0] == Y.shape[0]:
+            # trim the last one to be compatible with old behavior.
+            C = C[:-1]
         if self.orientation == 'vertical':
             args = (X, Y, C)
         else:
