Skip perfschema.misc if "var" is a symlink (due to Bug 51447).

mysql-test/include/not_var_link.inc:
  Committed on behalf of Bjorn.

mysql-test/include/not_var_link.inc

+perl;
+  open (ISLINK, ">" . $ENV{'MYSQL_TMP_DIR'} . "/mtr_var_link");
+  my $mvr= -l $ENV{'MYSQLTEST_VARDIR'} ? 1 : 0;
+  print ISLINK "let \$mtr_var_link= $mvr;\n";
+  close ISLINK;
+EOF
+
+--source $MYSQL_TMP_DIR/mtr_var_link
+--remove_file $MYSQL_TMP_DIR/mtr_var_link
+
+if ($mtr_var_link) {
+  --skip Test does not work with var being softlink
+}

mysql-test/suite/perfschema/t/misc.test

@@ -18,6 +18,7 @@
 
 --source include/not_embedded.inc
 --source include/have_perfschema.inc
+--source include/not_var_link.inc
 
 #
 # Bug#45496 Performance schema: assertion fails in