Fix TexManager's support for openout_any = p

The "paranoid" default of Kpathsea (TeX Live's path resolution system)
disallows access to parent directories.

Author: jtracey

lib/matplotlib/tests/test_texmanager.py

@@ -1,5 +1,8 @@
+import os
 from pathlib import Path
 import re
+import subprocess
+import sys
 
 import matplotlib.pyplot as plt
 from matplotlib.texmanager import TexManager
@@ -57,3 +60,15 @@ def test_unicode_characters():
     with pytest.raises(RuntimeError):
         ax.set_title('\N{SNOWMAN}')
         fig.canvas.draw()
+
+
+@needs_usetex
+def test_openin_any_paranoid():
+    completed = subprocess.run(
+        [sys.executable, "-c",
+         'import matplotlib.pyplot as plt;'
+         'plt.rcParams.update({"text.usetex": True});'
+         'plt.title("paranoid");'
+         'plt.show(block=False);'],
+        env={**os.environ, 'openin_any': 'p'}, check=True, capture_output=True)
+    assert completed.stderr == b""

lib/matplotlib/texmanager.py

@@ -291,12 +291,16 @@ def make_dvi(cls, tex, fontsize):
             # and thus replace() works atomically.  It also allows referring to
             # the texfile with a relative path (for pathological MPLCONFIGDIRs,
             # the absolute path may contain characters (e.g. ~) that TeX does
-            # not support.)
-            with TemporaryDirectory(dir=Path(dvifile).parent) as tmpdir:
+            # not support; n.b. relative paths cannot traverse parents, or it
+            # will be blocked when `openin_any = p` in texmf.cnf).
+            cwd = Path(dvifile).parent
+            with TemporaryDirectory(dir=cwd) as tmpdir:
+                tmppath = Path(tmpdir)
                 cls._run_checked_subprocess(
                     ["latex", "-interaction=nonstopmode", "--halt-on-error",
-                     f"../{texfile.name}"], tex, cwd=tmpdir)
-                (Path(tmpdir) / Path(dvifile).name).replace(dvifile)
+                     f"--output-directory={tmppath.name}",
+                     f"{texfile.name}"], tex, cwd=cwd)
+                (tmppath / Path(dvifile).name).replace(dvifile)
         return dvifile
 
     @classmethod