run_unittests: add test for passing symlinks to setup and test

run_unittests.py

@@ -6896,6 +6896,18 @@ class LinuxlikeTests(BasePlatformTests):
             pcfile = f.read()
         self.assertFalse('blub_blob_blib' in pcfile)
 
+    def test_symlink_builddir(self):
+        '''
+        Test using a symlink as either the builddir for "setup" or
+        the argument for "-C".
+        '''
+        testdir = os.path.join(self.common_test_dir, '1 trivial')
+        os.symlink(self.builddir, self.builddir + '-symlink')
+        self.change_builddir(self.builddir + '-symlink')
+        self.init(testdir)
+        self.build()
+        self._run(self.mtest_command)
+
     def test_vala_c_warnings(self):
         '''
         Test that no warnings are emitted for C code generated by Vala. This