Merge pull request #27660 from meeseeksmachine/auto-backport-of-pr-27624-on-v3.8.x

Backport PR #27624 on branch v3.8.x (Prepare for Pytest v8)

Author: rcomer

lib/matplotlib/backends/backend_pdf.py

@@ -2732,7 +2732,7 @@ def close(self):
             _api.warn_deprecated("3.8", message=(
                 "Keeping empty pdf files is deprecated since %(since)s and support "
                 "will be removed %(removal)s."))
-            PdfFile(self._filename, metadata=self._metadata)  # touch the file.
+            PdfFile(self._filename, metadata=self._metadata).close()  # touch the file.
 
     def infodict(self):
         """

lib/matplotlib/tests/test_colors.py

@@ -1,6 +1,7 @@
 import copy
 import itertools
 import unittest.mock
+from packaging.version import parse as parse_version
 
 from io import BytesIO
 import numpy as np
@@ -147,9 +148,13 @@ def test_double_register_builtin_cmap():
     with pytest.raises(ValueError, match='A colormap named "viridis"'):
         with pytest.warns(mpl.MatplotlibDeprecationWarning):
             cm.register_cmap(name, mpl.colormaps[name])
-    with pytest.warns(UserWarning):
-        # TODO is warning more than once!
-        cm.register_cmap(name, mpl.colormaps[name], override_builtin=True)
+
+    if parse_version(pytest.__version__).major < 8:
+        with pytest.warns(UserWarning):
+            cm.register_cmap(name, mpl.colormaps[name], override_builtin=True)
+    else:
+        with pytest.warns(UserWarning), pytest.warns(mpl.MatplotlibDeprecationWarning):
+            cm.register_cmap(name, mpl.colormaps[name], override_builtin=True)
 
 
 def test_unregister_builtin_cmap():

lib/matplotlib/tests/test_rcparams.py

@@ -106,14 +106,12 @@ def test_rcparams_update():
     rc = mpl.RcParams({'figure.figsize': (3.5, 42)})
     bad_dict = {'figure.figsize': (3.5, 42, 1)}
     # make sure validation happens on input
-    with pytest.raises(ValueError), \
-         pytest.warns(UserWarning, match="validate"):
+    with pytest.raises(ValueError):
         rc.update(bad_dict)
 
 
 def test_rcparams_init():
-    with pytest.raises(ValueError), \
-         pytest.warns(UserWarning, match="validate"):
+    with pytest.raises(ValueError):
         mpl.RcParams({'figure.figsize': (3.5, 42, 1)})
 
 

lib/matplotlib/tests/test_ticker.py

@@ -3,6 +3,7 @@
 import locale
 import logging
 import re
+from packaging.version import parse as parse_version
 
 import numpy as np
 from numpy.testing import assert_almost_equal, assert_array_equal
@@ -914,10 +915,17 @@ def test_mathtext_ticks(self):
             'axes.formatter.use_mathtext': False
         })
 
-        with pytest.warns(UserWarning, match='cmr10 font should ideally'):
-            fig, ax = plt.subplots()
-            ax.set_xticks([-1, 0, 1])
-            fig.canvas.draw()
+        if parse_version(pytest.__version__).major < 8:
+            with pytest.warns(UserWarning, match='cmr10 font should ideally'):
+                fig, ax = plt.subplots()
+                ax.set_xticks([-1, 0, 1])
+                fig.canvas.draw()
+        else:
+            with (pytest.warns(UserWarning, match="Glyph 8722"),
+                  pytest.warns(UserWarning, match='cmr10 font should ideally')):
+                fig, ax = plt.subplots()
+                ax.set_xticks([-1, 0, 1])
+                fig.canvas.draw()
 
     def test_cmr10_substitutions(self, caplog):
         mpl.rcParams.update({