Make sure SubFigure has _cachedRenderer

oscargus · oscargus · commit ad1dfe5932ef · 2022-06-01T13:23:42.000+02:00
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -2056,6 +2056,10 @@ def __init__(self, parent, subplotspec, *,
     def dpi(self):
         return self._parent.dpi
 
+    @property
+    def _cachedRenderer(self):
+        return self._parent._cachedRenderer
+
     @dpi.setter
     def dpi(self, value):
         self._parent.dpi = value
@@ -2134,7 +2138,6 @@ def axes(self):
 
     def draw(self, renderer):
         # docstring inherited
-        self._cachedRenderer = renderer
 
         # draw the figure bounding box, perhaps none for white figure
         if not self.get_visible():
diff --git a/lib/matplotlib/tests/test_contour.py b/lib/matplotlib/tests/test_contour.py
@@ -585,3 +585,23 @@ def test_all_algorithms():
         ax.contourf(x, y, z, algorithm=algorithm)
         ax.contour(x, y, z, algorithm=algorithm, colors='k')
         ax.set_title(algorithm)
+
+
+def test_subfigure_clabel():
+    # Smoke test for gh#23173
+    delta = 0.025
+    x = np.arange(-3.0, 3.0, delta)
+    y = np.arange(-2.0, 2.0, delta)
+    X, Y = np.meshgrid(x, y)
+    Z1 = np.exp(-(X**2) - Y**2)
+    Z2 = np.exp(-((X - 1) ** 2) - (Y - 1) ** 2)
+    Z = (Z1 - Z2) * 2
+
+    fig = plt.figure()
+    figs = fig.subfigures(nrows=1, ncols=2)
+
+    for f in figs:
+        ax = f.subplots()
+        CS = ax.contour(X, Y, Z)
+        ax.clabel(CS, inline=True, fontsize=10)
+        ax.set_title("Simplest default with labels")
