[3.10] bpo-38671: Add test that pathlib.Path.resolve() returns an absolute path. (pythonGH-26184)

Issue should be fixed in bpo-43757

Co-Authored-by: Tzu-ping Chung <uranusjr@gmail.com>
(cherry picked from commit 18f41c0)

Co-authored-by: Barney Gale <barney.gale@gmail.com>

Author: barneygale

Lib/test/test_pathlib.py

@@ -1799,6 +1799,16 @@ def test_resolve_dot(self):
         # Non-strict
         self.assertEqual(r.resolve(strict=False), p / '3' / '4')
 
+    def test_resolve_nonexist_relative_issue38671(self):
+        p = self.cls('non', 'exist')
+
+        old_cwd = os.getcwd()
+        os.chdir(BASE)
+        try:
+            self.assertEqual(p.resolve(), self.cls(BASE, p))
+        finally:
+            os.chdir(old_cwd)
+
     def test_with(self):
         p = self.cls(BASE)
         it = p.iterdir()