Raise an ValueError when Axes.pie accepts negative values

Inception95 · Inception95 · commit 1e230033a8a6 · 2019-12-13T16:53:57.000-08:00
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -2921,6 +2921,10 @@ def pie(self, x, explode=None, labels=None, colors=None,
                 "and will be removed %(removal)s; pass a 1D array instead.")
             x = np.atleast_1d(x.squeeze())
 
+        for part in x:
+            if part < 0:
+                raise ValueError("wedge sizes must be non negative values")
+
         sx = x.sum()
         if sx > 1:
             x = x / sx
